深入理解Yii2.0 行为

<?php
namespace common\behaviors;

use common\models\UserActionStatis;
use Yii;
use yii\base\Behavior;
use yii\base\Event;

/**
 * 用户操作统计行为类
 * Class UserActionStatisBehavior
 * @package common\behaviors
 */
class UserActionStatisBehavior extends Behavior
{
    const UPDATE_ONE_OF_USER_ACTION_STATIS = "updateOneOfUserActionStatis";

    // 操作人id
    public $do_user_id;
    // 操作地址
    public $action_addr;

    /**
     * @return array
     */
    public function events()
    {
        return [
            self::UPDATE_ONE_OF_USER_ACTION_STATIS => [$this, "updateOneOfUserActionStatis"]
        ];
    }

    /**
     * 获取当前操作次数
     * @return int|mixed
     */
    public function getActionSatisNum()
    {
        $user_id = $this->do_user_id;
        $action_addr = $this->action_addr;
        if (empty($action_addr)) {
            $action_addr = $this->owner->id .'/' .$this->owner->action->id;
        }
        $action_hash = hash("md5", $action_addr);

        $model = UserActionStatis::find()
            ->andWhere("user_id = :user_id", [":user_id" => $user_id])
            ->andWhere("action_hash = :action_hash", [":action_hash" => $action_hash])
            ->one();

        if (!empty($model)) {
            return $model->num;
        }

        return 0;
    }

    /**
     * 更新用户操作统计
     * @param Event $event
     * @return bool
     */
    public function updateOneOfUserActionStatis(Event $event)
    {
        $user_id = $this->do_user_id;
        $action_addr = $event->sender->id .'/' .$event->sender->action->id;
        $action_hash = hash("md5", $action_addr);

        $model = UserActionStatis::find()
            ->andWhere("user_id = :user_id", [":user_id" => $user_id])
            ->andWhere("action_hash = :action_hash", [":action_hash" => $action_hash])
            ->one();

        if (empty($model)) {
            $model = new UserActionStatis;
            $model->user_id = $user_id;
            $model->action_addr = $action_addr;
            $model->action_hash = $action_hash;
            $model->num = 1;
            $model->created_time = $model->updated_time = time();
        } else {
            $model->num++;
            $model->updated_time = time();
        }

        return $model->save();
    }
}

<?php
namespace common\models;

use Yii;
use yii\db\ActiveRecord;

class UserActionStatis extends ActiveRecord
{
    public static function getDb()
    {
        return Yii::$app->db;
    }

    public static function tableName()
    {
        return 'user_action_statis';
    }
}

<?php
namespace backend\controllers;

use Yii;
use yii\web\Controller;

class UserController extends Controller
{
    public function actionEditInfo()
    {
        /*保存操作*/
        
        // 附加行为
        $this->attachBehavior("userActionStatisBehavior", "\common\behaviors\UserActionStatisBehavior");
        $this->do_user_id = Yii::$app->user->id;
        
        // 触发事件
        $this->trigger(\common\behaviors\UserActionStatisBehavior::UPDATE_ONE_OF_USER_ACTION_STATIS);
        
        // 打印操作统计数
        echo $this->actionSatisNum;
    }
}
?>

<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\base;

use Yii;

/**
 * BaseObject is the base class that implements the *property* feature.
 *
 * A property is defined by a getter method (e.g. `getLabel`), and/or a setter method (e.g. `setLabel`). For example,
 * the following getter and setter methods define a property named `label`:
 *
 * 
 * private $_label;
 *
 * public function getLabel()
 * {
 *     return $this->_label;
 * }
 *
 * public function setLabel($value)
 * {
 *     $this->_label = $value;
 * }
 * 
 *
 * Property names are *case-insensitive*.
 *
 * A property can be accessed like a member variable of an object. Reading or writing a property will cause the invocation
 * of the corresponding getter or setter method. For example,
 *
 * 
 * // equivalent to $label = $object->getLabel();
 * $label = $object->label;
 * // equivalent to $object->setLabel('abc');
 * $object->label = 'abc';
 * 
 *
 * If a property has only a getter method and has no setter method, it is considered as *read-only*. In this case, trying
 * to modify the property value will cause an exception.
 *
 * One can call [[hasProperty()]], [[canGetProperty()]] and/or [[canSetProperty()]] to check the existence of a property.
 *
 * Besides the property feature, BaseObject also introduces an important object initialization life cycle. In particular,
 * creating an new instance of BaseObject or its derived class will involve the following life cycles sequentially:
 *
 * 1. the class constructor is invoked;
 * 2. object properties are initialized according to the given configuration;
 * 3. the `init()` method is invoked.
 *
 * In the above, both Step 2 and 3 occur at the end of the class constructor. It is recommended that
 * you perform object initialization in the `init()` method because at that stage, the object configuration
 * is already applied.
 *
 * In order to ensure the above life cycles, if a child class of BaseObject needs to override the constructor,
 * it should be done like the following:
 *
 * 
 * public function __construct($param1, $param2, ..., $config = [])
 * {
 *     ...
 *     parent::__construct($config);
 * }
 * 
 *
 * That is, a `$config` parameter (defaults to `[]`) should be declared as the last parameter
 * of the constructor, and the parent implementation should be called at the end of the constructor.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0.13
 */
class BaseObject implements Configurable
{
    /**
     * Returns the fully qualified name of this class.
     * @return string the fully qualified name of this class.
     * @deprecated since 2.0.14. On PHP >=5.5, use `::class` instead.
     */
    public static function className()
    {
        return get_called_class();
    }

    /**
     * Constructor.
     *
     * The default implementation does two things:
     *
     * - Initializes the object with the given configuration `$config`.
     * - Call [[init()]].
     *
     * If this method is overridden in a child class, it is recommended that
     *
     * - the last parameter of the constructor is a configuration array, like `$config` here.
     * - call the parent implementation at the end of the constructor.
     *
     * @param array $config name-value pairs that will be used to initialize the object properties
     */
    public function __construct($config = [])
    {
        if (!empty($config)) {
            Yii::configure($this, $config);
        }
        $this->init();
    }

    /**
     * Initializes the object.
     * This method is invoked at the end of the constructor after the object is initialized with the
     * given configuration.
     */
    public function init()
    {
    }

    /**
     * Returns the value of an object property.
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `$value = $object->property;`.
     * @param string $name the property name
     * @return mixed the property value
     * @throws UnknownPropertyException if the property is not defined
     * @throws InvalidCallException if the property is write-only
     * @see __set()
     */
    public function __get($name)
    {
        $getter = 'get' . $name;
        if (method_exists($this, $getter)) {
            return $this->$getter();
        } elseif (method_exists($this, 'set' . $name)) {
            throw new InvalidCallException('Getting write-only property: ' . get_class($this) . '::' . $name);
        }

        throw new UnknownPropertyException('Getting unknown property: ' . get_class($this) . '::' . $name);
    }

    /**
     * Sets value of an object property.
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `$object->property = $value;`.
     * @param string $name the property name or the event name
     * @param mixed $value the property value
     * @throws UnknownPropertyException if the property is not defined
     * @throws InvalidCallException if the property is read-only
     * @see __get()
     */
    public function __set($name, $value)
    {
        $setter = 'set' . $name;
        if (method_exists($this, $setter)) {
            $this->$setter($value);
        } elseif (method_exists($this, 'get' . $name)) {
            throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);
        } else {
            throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);
        }
    }

    /**
     * Checks if a property is set, i.e. defined and not null.
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `isset($object->property)`.
     *
     * Note that if the property is not defined, false will be returned.
     * @param string $name the property name or the event name
     * @return bool whether the named property is set (not null).
     * @see https://www.php.net/manual/en/function.isset.php
     */
    public function __isset($name)
    {
        $getter = 'get' . $name;
        if (method_exists($this, $getter)) {
            return $this->$getter() !== null;
        }

        return false;
    }

    /**
     * Sets an object property to null.
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `unset($object->property)`.
     *
     * Note that if the property is not defined, this method will do nothing.
     * If the property is read-only, it will throw an exception.
     * @param string $name the property name
     * @throws InvalidCallException if the property is read only.
     * @see https://www.php.net/manual/en/function.unset.php
     */
    public function __unset($name)
    {
        $setter = 'set' . $name;
        if (method_exists($this, $setter)) {
            $this->$setter(null);
        } elseif (method_exists($this, 'get' . $name)) {
            throw new InvalidCallException('Unsetting read-only property: ' . get_class($this) . '::' . $name);
        }
    }

    /**
     * Calls the named method which is not a class method.
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when an unknown method is being invoked.
     * @param string $name the method name
     * @param array $params method parameters
     * @throws UnknownMethodException when calling unknown method
     * @return mixed the method return value
     */
    public function __call($name, $params)
    {
        throw new UnknownMethodException('Calling unknown method: ' . get_class($this) . "::$name()");
    }

    /**
     * Returns a value indicating whether a property is defined.
     *
     * A property is defined if:
     *
     * - the class has a getter or setter method associated with the specified name
     *   (in this case, property name is case-insensitive);
     * - the class has a member variable with the specified name (when `$checkVars` is true);
     *
     * @param string $name the property name
     * @param bool $checkVars whether to treat member variables as properties
     * @return bool whether the property is defined
     * @see canGetProperty()
     * @see canSetProperty()
     */
    public function hasProperty($name, $checkVars = true)
    {
        return $this->canGetProperty($name, $checkVars) || $this->canSetProperty($name, false);
    }

    /**
     * Returns a value indicating whether a property can be read.
     *
     * A property is readable if:
     *
     * - the class has a getter method associated with the specified name
     *   (in this case, property name is case-insensitive);
     * - the class has a member variable with the specified name (when `$checkVars` is true);
     *
     * @param string $name the property name
     * @param bool $checkVars whether to treat member variables as properties
     * @return bool whether the property can be read
     * @see canSetProperty()
     */
    public function canGetProperty($name, $checkVars = true)
    {
        return method_exists($this, 'get' . $name) || $checkVars && property_exists($this, $name);
    }

    /**
     * Returns a value indicating whether a property can be set.
     *
     * A property is writable if:
     *
     * - the class has a setter method associated with the specified name
     *   (in this case, property name is case-insensitive);
     * - the class has a member variable with the specified name (when `$checkVars` is true);
     *
     * @param string $name the property name
     * @param bool $checkVars whether to treat member variables as properties
     * @return bool whether the property can be written
     * @see canGetProperty()
     */
    public function canSetProperty($name, $checkVars = true)
    {
        return method_exists($this, 'set' . $name) || $checkVars && property_exists($this, $name);
    }

    /**
     * Returns a value indicating whether a method is defined.
     *
     * The default implementation is a call to php function `method_exists()`.
     * You may override this method when you implemented the php magic method `__call()`.
     * @param string $name the method name
     * @return bool whether the method is defined
     */
    public function hasMethod($name)
    {
        return method_exists($this, $name);
    }
}

<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\base;

use Yii;
use yii\helpers\StringHelper;

/**
 * Component is the base class that implements the *property*, *event* and *behavior* features.
 *
 * Component provides the *event* and *behavior* features, in addition to the *property* feature which is implemented in
 * its parent class [[\yii\base\BaseObject|BaseObject]].
 *
 * Event is a way to "inject" custom code into existing code at certain places. For example, a comment object can trigger
 * an "add" event when the user adds a comment. We can write custom code and attach it to this event so that when the event
 * is triggered (i.e. comment will be added), our custom code will be executed.
 *
 * An event is identified by a name that should be unique within the class it is defined at. Event names are *case-sensitive*.
 *
 * One or multiple PHP callbacks, called *event handlers*, can be attached to an event. You can call [[trigger()]] to
 * raise an event. When an event is raised, the event handlers will be invoked automatically in the order they were
 * attached.
 *
 * To attach an event handler to an event, call [[on()]]:
 *
 * 
 * $post->on('update', function ($event) {
 *     // send email notification
 * });
 * 
 *
 * In the above, an anonymous function is attached to the "update" event of the post. You may attach
 * the following types of event handlers:
 *
 * - anonymous function: `function ($event) { ... }`
 * - object method: `[$object, 'handleAdd']`
 * - static class method: `['Page', 'handleAdd']`
 * - global function: `'handleAdd'`
 *
 * The signature of an event handler should be like the following:
 *
 * 
 * function foo($event)
 * 
 *
 * where `$event` is an [[Event]] object which includes parameters associated with the event.
 *
 * You can also attach a handler to an event when configuring a component with a configuration array.
 * The syntax is like the following:
 *
 * 
 * [
 *     'on add' => function ($event) { ... }
 * ]
 * 
 *
 * where `on add` stands for attaching an event to the `add` event.
 *
 * Sometimes, you may want to associate extra data with an event handler when you attach it to an event
 * and then access it when the handler is invoked. You may do so by
 *
 * 
 * $post->on('update', function ($event) {
 *     // the data can be accessed via $event->data
 * }, $data);
 * 
 *
 * A behavior is an instance of [[Behavior]] or its child class. A component can be attached with one or multiple
 * behaviors. When a behavior is attached to a component, its public properties and methods can be accessed via the
 * component directly, as if the component owns those properties and methods.
 *
 * To attach a behavior to a component, declare it in [[behaviors()]], or explicitly call [[attachBehavior]]. Behaviors
 * declared in [[behaviors()]] are automatically attached to the corresponding component.
 *
 * One can also attach a behavior to a component when configuring it with a configuration array. The syntax is like the
 * following:
 *
 * 
 * [
 *     'as tree' => [
 *         'class' => 'Tree',
 *     ],
 * ]
 * 
 *
 * where `as tree` stands for attaching a behavior named `tree`, and the array will be passed to [[\Yii::createObject()]]
 * to create the behavior object.
 *
 * For more details and usage information on Component, see the [guide article on components](guide:concept-components).
 *
 * @property-read Behavior[] $behaviors List of behaviors attached to this component.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class Component extends BaseObject
{
    /**
     * @var array the attached event handlers (event name => handlers)
     */
    private $_events = [];
    /**
     * @var array the event handlers attached for wildcard patterns (event name wildcard => handlers)
     * @since 2.0.14
     */
    private $_eventWildcards = [];
    /**
     * @var Behavior[]|null the attached behaviors (behavior name => behavior). This is `null` when not initialized.
     */
    private $_behaviors;


    /**
     * Returns the value of a component property.
     *
     * This method will check in the following order and act accordingly:
     *
     *  - a property defined by a getter: return the getter result
     *  - a property of a behavior: return the behavior property value
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `$value = $component->property;`.
     * @param string $name the property name
     * @return mixed the property value or the value of a behavior's property
     * @throws UnknownPropertyException if the property is not defined
     * @throws InvalidCallException if the property is write-only.
     * @see __set()
     */
    public function __get($name)
    {
        $getter = 'get' . $name;
        if (method_exists($this, $getter)) {
            // read property, e.g. getName()
            return $this->$getter();
        }

        // behavior property
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canGetProperty($name)) {
                return $behavior->$name;
            }
        }

        if (method_exists($this, 'set' . $name)) {
            throw new InvalidCallException('Getting write-only property: ' . get_class($this) . '::' . $name);
        }

        throw new UnknownPropertyException('Getting unknown property: ' . get_class($this) . '::' . $name);
    }

    /**
     * Sets the value of a component property.
     *
     * This method will check in the following order and act accordingly:
     *
     *  - a property defined by a setter: set the property value
     *  - an event in the format of "on xyz": attach the handler to the event "xyz"
     *  - a behavior in the format of "as xyz": attach the behavior named as "xyz"
     *  - a property of a behavior: set the behavior property value
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `$component->property = $value;`.
     * @param string $name the property name or the event name
     * @param mixed $value the property value
     * @throws UnknownPropertyException if the property is not defined
     * @throws InvalidCallException if the property is read-only.
     * @see __get()
     */
    public function __set($name, $value)
    {
        $setter = 'set' . $name;
        if (method_exists($this, $setter)) {
            // set property
            $this->$setter($value);

            return;
        } elseif (strncmp($name, 'on ', 3) === 0) {
            // on event: attach event handler
            $this->on(trim(substr($name, 3)), $value);

            return;
        } elseif (strncmp($name, 'as ', 3) === 0) {
            // as behavior: attach behavior
            $name = trim(substr($name, 3));
            $this->attachBehavior($name, $value instanceof Behavior ? $value : Yii::createObject($value));

            return;
        }

        // behavior property
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canSetProperty($name)) {
                $behavior->$name = $value;
                return;
            }
        }

        if (method_exists($this, 'get' . $name)) {
            throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);
        }

        throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);
    }

    /**
     * Checks if a property is set, i.e. defined and not null.
     *
     * This method will check in the following order and act accordingly:
     *
     *  - a property defined by a setter: return whether the property is set
     *  - a property of a behavior: return whether the property is set
     *  - return `false` for non existing properties
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `isset($component->property)`.
     * @param string $name the property name or the event name
     * @return bool whether the named property is set
     * @see https://www.php.net/manual/en/function.isset.php
     */
    public function __isset($name)
    {
        $getter = 'get' . $name;
        if (method_exists($this, $getter)) {
            return $this->$getter() !== null;
        }

        // behavior property
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canGetProperty($name)) {
                return $behavior->$name !== null;
            }
        }

        return false;
    }

    /**
     * Sets a component property to be null.
     *
     * This method will check in the following order and act accordingly:
     *
     *  - a property defined by a setter: set the property value to be null
     *  - a property of a behavior: set the property value to be null
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `unset($component->property)`.
     * @param string $name the property name
     * @throws InvalidCallException if the property is read only.
     * @see https://www.php.net/manual/en/function.unset.php
     */
    public function __unset($name)
    {
        $setter = 'set' . $name;
        if (method_exists($this, $setter)) {
            $this->$setter(null);
            return;
        }

        // behavior property
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canSetProperty($name)) {
                $behavior->$name = null;
                return;
            }
        }

        throw new InvalidCallException('Unsetting an unknown or read-only property: ' . get_class($this) . '::' . $name);
    }

    /**
     * Calls the named method which is not a class method.
     *
     * This method will check if any attached behavior has
     * the named method and will execute it if available.
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when an unknown method is being invoked.
     * @param string $name the method name
     * @param array $params method parameters
     * @return mixed the method return value
     * @throws UnknownMethodException when calling unknown method
     */
    public function __call($name, $params)
    {
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $object) {
            if ($object->hasMethod($name)) {
                return call_user_func_array([$object, $name], $params);
            }
        }
        throw new UnknownMethodException('Calling unknown method: ' . get_class($this) . "::$name()");
    }

    /**
     * This method is called after the object is created by cloning an existing one.
     * It removes all behaviors because they are attached to the old object.
     */
    public function __clone()
    {
        $this->_events = [];
        $this->_eventWildcards = [];
        $this->_behaviors = null;
    }

    /**
     * Returns a value indicating whether a property is defined for this component.
     *
     * A property is defined if:
     *
     * - the class has a getter or setter method associated with the specified name
     *   (in this case, property name is case-insensitive);
     * - the class has a member variable with the specified name (when `$checkVars` is true);
     * - an attached behavior has a property of the given name (when `$checkBehaviors` is true).
     *
     * @param string $name the property name
     * @param bool $checkVars whether to treat member variables as properties
     * @param bool $checkBehaviors whether to treat behaviors' properties as properties of this component
     * @return bool whether the property is defined
     * @see canGetProperty()
     * @see canSetProperty()
     */
    public function hasProperty($name, $checkVars = true, $checkBehaviors = true)
    {
        return $this->canGetProperty($name, $checkVars, $checkBehaviors) || $this->canSetProperty($name, false, $checkBehaviors);
    }

    /**
     * Returns a value indicating whether a property can be read.
     *
     * A property can be read if:
     *
     * - the class has a getter method associated with the specified name
     *   (in this case, property name is case-insensitive);
     * - the class has a member variable with the specified name (when `$checkVars` is true);
     * - an attached behavior has a readable property of the given name (when `$checkBehaviors` is true).
     *
     * @param string $name the property name
     * @param bool $checkVars whether to treat member variables as properties
     * @param bool $checkBehaviors whether to treat behaviors' properties as properties of this component
     * @return bool whether the property can be read
     * @see canSetProperty()
     */
    public function canGetProperty($name, $checkVars = true, $checkBehaviors = true)
    {
        if (method_exists($this, 'get' . $name) || $checkVars && property_exists($this, $name)) {
            return true;
        } elseif ($checkBehaviors) {
            $this->ensureBehaviors();
            foreach ($this->_behaviors as $behavior) {
                if ($behavior->canGetProperty($name, $checkVars)) {
                    return true;
                }
            }
        }

        return false;
    }

    /**
     * Returns a value indicating whether a property can be set.
     *
     * A property can be written if:
     *
     * - the class has a setter method associated with the specified name
     *   (in this case, property name is case-insensitive);
     * - the class has a member variable with the specified name (when `$checkVars` is true);
     * - an attached behavior has a writable property of the given name (when `$checkBehaviors` is true).
     *
     * @param string $name the property name
     * @param bool $checkVars whether to treat member variables as properties
     * @param bool $checkBehaviors whether to treat behaviors' properties as properties of this component
     * @return bool whether the property can be written
     * @see canGetProperty()
     */
    public function canSetProperty($name, $checkVars = true, $checkBehaviors = true)
    {
        if (method_exists($this, 'set' . $name) || $checkVars && property_exists($this, $name)) {
            return true;
        } elseif ($checkBehaviors) {
            $this->ensureBehaviors();
            foreach ($this->_behaviors as $behavior) {
                if ($behavior->canSetProperty($name, $checkVars)) {
                    return true;
                }
            }
        }

        return false;
    }

    /**
     * Returns a value indicating whether a method is defined.
     *
     * A method is defined if:
     *
     * - the class has a method with the specified name
     * - an attached behavior has a method with the given name (when `$checkBehaviors` is true).
     *
     * @param string $name the property name
     * @param bool $checkBehaviors whether to treat behaviors' methods as methods of this component
     * @return bool whether the method is defined
     */
    public function hasMethod($name, $checkBehaviors = true)
    {
        if (method_exists($this, $name)) {
            return true;
        } elseif ($checkBehaviors) {
            $this->ensureBehaviors();
            foreach ($this->_behaviors as $behavior) {
                if ($behavior->hasMethod($name)) {
                    return true;
                }
            }
        }

        return false;
    }

    /**
     * Returns a list of behaviors that this component should behave as.
     *
     * Child classes may override this method to specify the behaviors they want to behave as.
     *
     * The return value of this method should be an array of behavior objects or configurations
     * indexed by behavior names. A behavior configuration can be either a string specifying
     * the behavior class or an array of the following structure:
     *
     * ```php
     * 'behaviorName' => [
     *     'class' => 'BehaviorClass',
     *     'property1' => 'value1',
     *     'property2' => 'value2',
     * ]
     * ```
     *
     * Note that a behavior class must extend from [[Behavior]]. Behaviors can be attached using a name or anonymously.
     * When a name is used as the array key, using this name, the behavior can later be retrieved using [[getBehavior()]]
     * or be detached using [[detachBehavior()]]. Anonymous behaviors can not be retrieved or detached.
     *
     * Behaviors declared in this method will be attached to the component automatically (on demand).
     *
     * @return array the behavior configurations.
     */
    public function behaviors()
    {
        return [];
    }

    /**
     * Returns a value indicating whether there is any handler attached to the named event.
     * @param string $name the event name
     * @return bool whether there is any handler attached to the event.
     */
    public function hasEventHandlers($name)
    {
        $this->ensureBehaviors();

        if (!empty($this->_events[$name])) {
            return true;
        }

        foreach ($this->_eventWildcards as $wildcard => $handlers) {
            if (!empty($handlers) && StringHelper::matchWildcard($wildcard, $name)) {
                return true;
            }
        }

        return Event::hasHandlers($this, $name);
    }

    /**
     * Attaches an event handler to an event.
     *
     * The event handler must be a valid PHP callback. The following are
     * some examples:
     *
     * ```
     * function ($event) { ... }         // anonymous function
     * [$object, 'handleClick']          // $object->handleClick()
     * ['Page', 'handleClick']           // Page::handleClick()
     * 'handleClick'                     // global function handleClick()
     * ```
     *
     * The event handler must be defined with the following signature,
     *
     * ```
     * function ($event)
     * ```
     *
     * where `$event` is an [[Event]] object which includes parameters associated with the event.
     *
     * Since 2.0.14 you can specify event name as a wildcard pattern:
     *
     * ```php
     * $component->on('event.group.*', function ($event) {
     *     Yii::trace($event->name . ' is triggered.');
     * });
     * ```
     *
     * @param string $name the event name
     * @param callable $handler the event handler
     * @param mixed $data the data to be passed to the event handler when the event is triggered.
     * When the event handler is invoked, this data can be accessed via [[Event::data]].
     * @param bool $append whether to append new event handler to the end of the existing
     * handler list. If false, the new handler will be inserted at the beginning of the existing
     * handler list.
     * @see off()
     */
    public function on($name, $handler, $data = null, $append = true)
    {
        $this->ensureBehaviors();

        if (strpos($name, '*') !== false) {
            if ($append || empty($this->_eventWildcards[$name])) {
                $this->_eventWildcards[$name][] = [$handler, $data];
            } else {
                array_unshift($this->_eventWildcards[$name], [$handler, $data]);
            }
            return;
        }

        if ($append || empty($this->_events[$name])) {
            $this->_events[$name][] = [$handler, $data];
        } else {
            array_unshift($this->_events[$name], [$handler, $data]);
        }
    }

    /**
     * Detaches an existing event handler from this component.
     *
     * This method is the opposite of [[on()]].
     *
     * Note: in case wildcard pattern is passed for event name, only the handlers registered with this
     * wildcard will be removed, while handlers registered with plain names matching this wildcard will remain.
     *
     * @param string $name event name
     * @param callable $handler the event handler to be removed.
     * If it is null, all handlers attached to the named event will be removed.
     * @return bool if a handler is found and detached
     * @see on()
     */
    public function off($name, $handler = null)
    {
        $this->ensureBehaviors();
        if (empty($this->_events[$name]) && empty($this->_eventWildcards[$name])) {
            return false;
        }
        if ($handler === null) {
            unset($this->_events[$name], $this->_eventWildcards[$name]);
            return true;
        }

        $removed = false;
        // plain event names
        if (isset($this->_events[$name])) {
            foreach ($this->_events[$name] as $i => $event) {
                if ($event[0] === $handler) {
                    unset($this->_events[$name][$i]);
                    $removed = true;
                }
            }
            if ($removed) {
                $this->_events[$name] = array_values($this->_events[$name]);
                return true;
            }
        }

        // wildcard event names
        if (isset($this->_eventWildcards[$name])) {
            foreach ($this->_eventWildcards[$name] as $i => $event) {
                if ($event[0] === $handler) {
                    unset($this->_eventWildcards[$name][$i]);
                    $removed = true;
                }
            }
            if ($removed) {
                $this->_eventWildcards[$name] = array_values($this->_eventWildcards[$name]);
                // remove empty wildcards to save future redundant regex checks:
                if (empty($this->_eventWildcards[$name])) {
                    unset($this->_eventWildcards[$name]);
                }
            }
        }

        return $removed;
    }

    /**
     * Triggers an event.
     *
     * This method represents the happening of an event. It invokes all attached handlers for the event
     * including class-level handlers.
     *
     * @param string $name the event name
     * @param Event|null $event the event instance. If not set, a default [[Event]] object will be created.
     */
    public function trigger($name, Event $event = null)
    {
        $this->ensureBehaviors();

        $eventHandlers = [];
        foreach ($this->_eventWildcards as $wildcard => $handlers) {
            if (StringHelper::matchWildcard($wildcard, $name)) {
                $eventHandlers[] = $handlers;
            }
        }
        if (!empty($this->_events[$name])) {
            $eventHandlers[] = $this->_events[$name];
        }

        if (!empty($eventHandlers)) {
            $eventHandlers = call_user_func_array('array_merge', $eventHandlers);
            if ($event === null) {
                $event = new Event();
            }
            if ($event->sender === null) {
                $event->sender = $this;
            }
            $event->handled = false;
            $event->name = $name;
            foreach ($eventHandlers as $handler) {
                $event->data = $handler[1];
                call_user_func($handler[0], $event);
                // stop further handling if the event is handled
                if ($event->handled) {
                    return;
                }
            }
        }

        // invoke class-level attached handlers
        Event::trigger($this, $name, $event);
    }

    /**
     * Returns the named behavior object.
     * @param string $name the behavior name
     * @return null|Behavior the behavior object, or null if the behavior does not exist
     */
    public function getBehavior($name)
    {
        $this->ensureBehaviors();
        return isset($this->_behaviors[$name]) ? $this->_behaviors[$name] : null;
    }

    /**
     * Returns all behaviors attached to this component.
     * @return Behavior[] list of behaviors attached to this component
     */
    public function getBehaviors()
    {
        $this->ensureBehaviors();
        return $this->_behaviors;
    }

    /**
     * Attaches a behavior to this component.
     * This method will create the behavior object based on the given
     * configuration. After that, the behavior object will be attached to
     * this component by calling the [[Behavior::attach()]] method.
     * @param string $name the name of the behavior.
     * @param string|array|Behavior $behavior the behavior configuration. This can be one of the following:
     *
     *  - a [[Behavior]] object
     *  - a string specifying the behavior class
     *  - an object configuration array that will be passed to [[Yii::createObject()]] to create the behavior object.
     *
     * @return Behavior the behavior object
     * @see detachBehavior()
     */
    public function attachBehavior($name, $behavior)
    {
        $this->ensureBehaviors();
        return $this->attachBehaviorInternal($name, $behavior);
    }

    /**
     * Attaches a list of behaviors to the component.
     * Each behavior is indexed by its name and should be a [[Behavior]] object,
     * a string specifying the behavior class, or an configuration array for creating the behavior.
     * @param array $behaviors list of behaviors to be attached to the component
     * @see attachBehavior()
     */
    public function attachBehaviors($behaviors)
    {
        $this->ensureBehaviors();
        foreach ($behaviors as $name => $behavior) {
            $this->attachBehaviorInternal($name, $behavior);
        }
    }

    /**
     * Detaches a behavior from the component.
     * The behavior's [[Behavior::detach()]] method will be invoked.
     * @param string $name the behavior's name.
     * @return null|Behavior the detached behavior. Null if the behavior does not exist.
     */
    public function detachBehavior($name)
    {
        $this->ensureBehaviors();
        if (isset($this->_behaviors[$name])) {
            $behavior = $this->_behaviors[$name];
            unset($this->_behaviors[$name]);
            $behavior->detach();
            return $behavior;
        }

        return null;
    }

    /**
     * Detaches all behaviors from the component.
     */
    public function detachBehaviors()
    {
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $name => $behavior) {
            $this->detachBehavior($name);
        }
    }

    /**
     * Makes sure that the behaviors declared in [[behaviors()]] are attached to this component.
     */
    public function ensureBehaviors()
    {
        if ($this->_behaviors === null) {
            $this->_behaviors = [];
            foreach ($this->behaviors() as $name => $behavior) {
                $this->attachBehaviorInternal($name, $behavior);
            }
        }
    }

    /**
     * Attaches a behavior to this component.
     * @param string|int $name the name of the behavior. If this is an integer, it means the behavior
     * is an anonymous one. Otherwise, the behavior is a named one and any existing behavior with the same name
     * will be detached first.
     * @param string|array|Behavior $behavior the behavior to be attached
     * @return Behavior the attached behavior.
     */
    private function attachBehaviorInternal($name, $behavior)
    {
        if (!($behavior instanceof Behavior)) {
            $behavior = Yii::createObject($behavior);
        }
        if (is_int($name)) {
            $behavior->attach($this);
            $this->_behaviors[] = $behavior;
        } else {
            if (isset($this->_behaviors[$name])) {
                $this->_behaviors[$name]->detach();
            }
            $behavior->attach($this);
            $this->_behaviors[$name] = $behavior;
        }

        return $behavior;
    }
}

<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\base;

/**
 * Behavior is the base class for all behavior classes.
 *
 * A behavior can be used to enhance the functionality of an existing component without modifying its code.
 * In particular, it can "inject" its own methods and properties into the component
 * and make them directly accessible via the component. It can also respond to the events triggered in the component
 * and thus intercept the normal code execution.
 *
 * For more details and usage information on Behavior, see the [guide article on behaviors](guide:concept-behaviors).
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class Behavior extends BaseObject
{
    /**
     * @var Component|null the owner of this behavior
     */
    public $owner;

    /**
     * @var array Attached events handlers
     */
    private $_attachedEvents = [];


    /**
     * Declares event handlers for the [[owner]]'s events.
     *
     * Child classes may override this method to declare what PHP callbacks should
     * be attached to the events of the [[owner]] component.
     *
     * The callbacks will be attached to the [[owner]]'s events when the behavior is
     * attached to the owner; and they will be detached from the events when
     * the behavior is detached from the component.
     *
     * The callbacks can be any of the following:
     *
     * - method in this behavior: `'handleClick'`, equivalent to `[$this, 'handleClick']`
     * - object method: `[$object, 'handleClick']`
     * - static method: `['Page', 'handleClick']`
     * - anonymous function: `function ($event) { ... }`
     *
     * The following is an example:
     *
     * ```php
     * [
     *     Model::EVENT_BEFORE_VALIDATE => 'myBeforeValidate',
     *     Model::EVENT_AFTER_VALIDATE => 'myAfterValidate',
     * ]
     * ```
     *
     * @return array events (array keys) and the corresponding event handler methods (array values).
     */
    public function events()
    {
        return [];
    }

    /**
     * Attaches the behavior object to the component.
     * The default implementation will set the [[owner]] property
     * and attach event handlers as declared in [[events]].
     * Make sure you call the parent implementation if you override this method.
     * @param Component $owner the component that this behavior is to be attached to.
     */
    public function attach($owner)
    {
        $this->owner = $owner;
        foreach ($this->events() as $event => $handler) {
            $this->_attachedEvents[$event] = $handler;
            $owner->on($event, is_string($handler) ? [$this, $handler] : $handler);
        }
    }

    /**
     * Detaches the behavior object from the component.
     * The default implementation will unset the [[owner]] property
     * and detach event handlers declared in [[events]].
     * Make sure you call the parent implementation if you override this method.
     */
    public function detach()
    {
        if ($this->owner) {
            foreach ($this->_attachedEvents as $event => $handler) {
                $this->owner->off($event, is_string($handler) ? [$this, $handler] : $handler);
            }
            $this->_attachedEvents = [];
            $this->owner = null;
        }
    }
}

<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\behaviors;

use Closure;
use yii\base\Behavior;
use yii\base\Event;
use yii\db\ActiveRecord;

/**
 * AttributeBehavior automatically assigns a specified value to one or multiple attributes of an ActiveRecord
 * object when certain events happen.
 *
 * To use AttributeBehavior, configure the [[attributes]] property which should specify the list of attributes
 * that need to be updated and the corresponding events that should trigger the update. Then configure the
 * [[value]] property with a PHP callable whose return value will be used to assign to the current attribute(s).
 * For example,
 *
 * 
 * use yii\behaviors\AttributeBehavior;
 *
 * public function behaviors()
 * {
 *     return [
 *         [
 *             'class' => AttributeBehavior::class,
 *             'attributes' => [
 *                 ActiveRecord::EVENT_BEFORE_INSERT => 'attribute1',
 *                 ActiveRecord::EVENT_BEFORE_UPDATE => 'attribute2',
 *             ],
 *             'value' => function ($event) {
 *                 return 'some value';
 *             },
 *         ],
 *     ];
 * }
 * 
 *
 * Because attribute values will be set automatically by this behavior, they are usually not user input and should therefore
 * not be validated, i.e. they should not appear in the [[\yii\base\Model::rules()|rules()]] method of the model.
 *
 * @author Luciano Baraglia <luciano.baraglia@gmail.com>
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class AttributeBehavior extends Behavior
{
    /**
     * @var array list of attributes that are to be automatically filled with the value specified via [[value]].
     * The array keys are the ActiveRecord events upon which the attributes are to be updated,
     * and the array values are the corresponding attribute(s) to be updated. You can use a string to represent
     * a single attribute, or an array to represent a list of attributes. For example,
     *
     * ```php
     * [
     *     ActiveRecord::EVENT_BEFORE_INSERT => ['attribute1', 'attribute2'],
     *     ActiveRecord::EVENT_BEFORE_UPDATE => 'attribute2',
     * ]
     * ```
     */
    public $attributes = [];
    /**
     * @var mixed the value that will be assigned to the current attributes. This can be an anonymous function,
     * callable in array format (e.g. `[$this, 'methodName']`), an [[\yii\db\Expression|Expression]] object representing a DB expression
     * (e.g. `new Expression('NOW()')`), scalar, string or an arbitrary value. If the former, the return value of the
     * function will be assigned to the attributes.
     * The signature of the function should be as follows,
     *
     * ```php
     * function ($event)
     * {
     *     // return value will be assigned to the attribute
     * }
     * ```
     */
    public $value;
    /**
     * @var bool whether to skip this behavior when the `$owner` has not been
     * modified
     * @since 2.0.8
     */
    public $skipUpdateOnClean = true;
    /**
     * @var bool whether to preserve non-empty attribute values.
     * @since 2.0.13
     */
    public $preserveNonEmptyValues = false;


    /**
     * {@inheritdoc}
     */
    public function events()
    {
        return array_fill_keys(
            array_keys($this->attributes),
            'evaluateAttributes'
        );
    }

    /**
     * Evaluates the attribute value and assigns it to the current attributes.
     * @param Event $event
     */
    public function evaluateAttributes($event)
    {
        if ($this->skipUpdateOnClean
            && $event->name == ActiveRecord::EVENT_BEFORE_UPDATE
            && empty($this->owner->dirtyAttributes)
        ) {
            return;
        }

        if (!empty($this->attributes[$event->name])) {
            $attributes = (array) $this->attributes[$event->name];
            $value = $this->getValue($event);
            foreach ($attributes as $attribute) {
                // ignore attribute names which are not string (e.g. when set by TimestampBehavior::updatedAtAttribute)
                if (is_string($attribute)) {
                    if ($this->preserveNonEmptyValues && !empty($this->owner->$attribute)) {
                        continue;
                    }
                    $this->owner->$attribute = $value;
                }
            }
        }
    }

    /**
     * Returns the value for the current attributes.
     * This method is called by [[evaluateAttributes()]]. Its return value will be assigned
     * to the attributes corresponding to the triggering event.
     * @param Event $event the event that triggers the current attribute updating.
     * @return mixed the attribute value
     */
    protected function getValue($event)
    {
        if ($this->value instanceof Closure || (is_array($this->value) && is_callable($this->value))) {
            return call_user_func($this->value, $event);
        }

        return $this->value;
    }
}

<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\behaviors;

use yii\base\InvalidCallException;
use yii\db\BaseActiveRecord;

/**
 * TimestampBehavior automatically fills the specified attributes with the current timestamp.
 *
 * To use TimestampBehavior, insert the following code to your ActiveRecord class:
 *
 * 
 * use yii\behaviors\TimestampBehavior;
 *
 * public function behaviors()
 * {
 *     return [
 *         TimestampBehavior::class,
 *     ];
 * }
 * 
 *
 * By default, TimestampBehavior will fill the `created_at` and `updated_at` attributes with the current timestamp
 * when the associated AR object is being inserted; it will fill the `updated_at` attribute
 * with the timestamp when the AR object is being updated. The timestamp value is obtained by `time()`.
 *
 * Because attribute values will be set automatically by this behavior, they are usually not user input and should therefore
 * not be validated, i.e. `created_at` and `updated_at` should not appear in the [[\yii\base\Model::rules()|rules()]] method of the model.
 *
 * For the above implementation to work with MySQL database, please declare the columns(`created_at`, `updated_at`) as int(11) for being UNIX timestamp.
 *
 * If your attribute names are different or you want to use a different way of calculating the timestamp,
 * you may configure the [[createdAtAttribute]], [[updatedAtAttribute]] and [[value]] properties like the following:
 *
 * 
 * use yii\db\Expression;
 *
 * public function behaviors()
 * {
 *     return [
 *         [
 *             'class' => TimestampBehavior::class,
 *             'createdAtAttribute' => 'create_time',
 *             'updatedAtAttribute' => 'update_time',
 *             'value' => new Expression('NOW()'),
 *         ],
 *     ];
 * }
 * 
 *
 * In case you use an [[\yii\db\Expression]] object as in the example above, the attribute will not hold the timestamp value, but
 * the Expression object itself after the record has been saved. If you need the value from DB afterwards you should call
 * the [[\yii\db\ActiveRecord::refresh()|refresh()]] method of the record.
 *
 * TimestampBehavior also provides a method named [[touch()]] that allows you to assign the current
 * timestamp to the specified attribute(s) and save them to the database. For example,
 *
 * 
 * $model->touch('creation_time');
 *
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @author Alexander Kochetov <creocoder@gmail.com>
 * @since 2.0
 */
class TimestampBehavior extends AttributeBehavior
{
    /**
     * @var string the attribute that will receive timestamp value
     * Set this property to false if you do not want to record the creation time.
     */
    public $createdAtAttribute = 'created_at';
    /**
     * @var string the attribute that will receive timestamp value.
     * Set this property to false if you do not want to record the update time.
     */
    public $updatedAtAttribute = 'updated_at';
    /**
     * {@inheritdoc}
     *
     * In case, when the value is `null`, the result of the PHP function [time()](https://www.php.net/manual/en/function.time.php)
     * will be used as value.
     */
    public $value;


    /**
     * {@inheritdoc}
     */
    public function init()
    {
        parent::init();

        if (empty($this->attributes)) {
            $this->attributes = [
                BaseActiveRecord::EVENT_BEFORE_INSERT => [$this->createdAtAttribute, $this->updatedAtAttribute],
                BaseActiveRecord::EVENT_BEFORE_UPDATE => $this->updatedAtAttribute,
            ];
        }
    }

    /**
     * {@inheritdoc}
     *
     * In case, when the [[value]] is `null`, the result of the PHP function [time()](https://www.php.net/manual/en/function.time.php)
     * will be used as value.
     */
    protected function getValue($event)
    {
        if ($this->value === null) {
            return time();
        }

        return parent::getValue($event);
    }

    /**
     * Updates a timestamp attribute to the current timestamp.
     *
     * ```php
     * $model->touch('lastVisit');
     * ```
     * @param string $attribute the name of the attribute to update.
     * @throws InvalidCallException if owner is a new record (since version 2.0.6).
     */
    public function touch($attribute)
    {
        /* @var $owner BaseActiveRecord */
        $owner = $this->owner;
        if ($owner->getIsNewRecord()) {
            throw new InvalidCallException('Updating the timestamp is not possible on a new record.');
        }
        $owner->updateAttributes(array_fill_keys((array) $attribute, $this->getValue(null)));
    }
}

<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\base;

use ArrayAccess;
use ArrayIterator;
use ArrayObject;
use IteratorAggregate;
use ReflectionClass;
use Yii;
use yii\helpers\Inflector;
use yii\validators\RequiredValidator;
use yii\validators\Validator;

/**
 * Model is the base class for data models.
 *
 * Model implements the following commonly used features:
 *
 * - attribute declaration: by default, every public class member is considered as
 *   a model attribute
 * - attribute labels: each attribute may be associated with a label for display purpose
 * - massive attribute assignment
 * - scenario-based validation
 *
 * Model also raises the following events when performing data validation:
 *
 * - [[EVENT_BEFORE_VALIDATE]]: an event raised at the beginning of [[validate()]]
 * - [[EVENT_AFTER_VALIDATE]]: an event raised at the end of [[validate()]]
 *
 * You may directly use Model to store model data, or extend it with customization.
 *
 * For more details and usage information on Model, see the [guide article on models](guide:structure-models).
 *
 * @property-read \yii\validators\Validator[] $activeValidators The validators applicable to the current
 * [[scenario]].
 * @property array $attributes Attribute values (name => value).
 * @property-read array $errors Errors for all attributes or the specified attribute. Empty array is returned
 * if no error. See [[getErrors()]] for detailed description. Note that when returning errors for all attributes,
 * the result is a two-dimensional array, like the following: ```php [ 'username' => [ 'Username is required.',
 * 'Username must contain only word characters.', ], 'email' => [ 'Email address is invalid.', ] ] ``` .
 * @property-read array $firstErrors The first errors. The array keys are the attribute names, and the array
 * values are the corresponding error messages. An empty array will be returned if there is no error.
 * @property-read ArrayIterator $iterator An iterator for traversing the items in the list.
 * @property string $scenario The scenario that this model is in. Defaults to [[SCENARIO_DEFAULT]].
 * @property-read ArrayObject|\yii\validators\Validator[] $validators All the validators declared in the
 * model.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class Model extends Component implements StaticInstanceInterface, IteratorAggregate, ArrayAccess, Arrayable
{
    use ArrayableTrait;
    use StaticInstanceTrait;

    /**
     * The name of the default scenario.
     */
    const SCENARIO_DEFAULT = 'default';
    /**
     * @event ModelEvent an event raised at the beginning of [[validate()]]. You may set
     * [[ModelEvent::isValid]] to be false to stop the validation.
     */
    const EVENT_BEFORE_VALIDATE = 'beforeValidate';
    /**
     * @event Event an event raised at the end of [[validate()]]
     */
    const EVENT_AFTER_VALIDATE = 'afterValidate';

    /**
     * @var array validation errors (attribute name => array of errors)
     */
    private $_errors;
    /**
     * @var ArrayObject list of validators
     */
    private $_validators;
    /**
     * @var string current scenario
     */
    private $_scenario = self::SCENARIO_DEFAULT;


    /**
     * Returns the validation rules for attributes.
     *
     * Validation rules are used by [[validate()]] to check if attribute values are valid.
     * Child classes may override this method to declare different validation rules.
     *
     * Each rule is an array with the following structure:
     *
     * ```php
     * [
     *     ['attribute1', 'attribute2'],
     *     'validator type',
     *     'on' => ['scenario1', 'scenario2'],
     *     //...other parameters...
     * ]
     * ```
     *
     * where
     *
     *  - attribute list: required, specifies the attributes array to be validated, for single attribute you can pass a string;
     *  - validator type: required, specifies the validator to be used. It can be a built-in validator name,
     *    a method name of the model class, an anonymous function, or a validator class name.
     *  - on: optional, specifies the [[scenario|scenarios]] array in which the validation
     *    rule can be applied. If this option is not set, the rule will apply to all scenarios.
     *  - additional name-value pairs can be specified to initialize the corresponding validator properties.
     *    Please refer to individual validator class API for possible properties.
     *
     * A validator can be either an object of a class extending [[Validator]], or a model class method
     * (called *inline validator*) that has the following signature:
     *
     * ```php
     * // $params refers to validation parameters given in the rule
     * function validatorName($attribute, $params)
     * ```
     *
     * In the above `$attribute` refers to the attribute currently being validated while `$params` contains an array of
     * validator configuration options such as `max` in case of `string` validator. The value of the attribute currently being validated
     * can be accessed as `$this->$attribute`. Note the `$` before `attribute`; this is taking the value of the variable
     * `$attribute` and using it as the name of the property to access.
     *
     * Yii also provides a set of [[Validator::builtInValidators|built-in validators]].
     * Each one has an alias name which can be used when specifying a validation rule.
     *
     * Below are some examples:
     *
     * ```php
     * [
     *     // built-in "required" validator
     *     [['username', 'password'], 'required'],
     *     // built-in "string" validator customized with "min" and "max" properties
     *     ['username', 'string', 'min' => 3, 'max' => 12],
     *     // built-in "compare" validator that is used in "register" scenario only
     *     ['password', 'compare', 'compareAttribute' => 'password2', 'on' => 'register'],
     *     // an inline validator defined via the "authenticate()" method in the model class
     *     ['password', 'authenticate', 'on' => 'login'],
     *     // a validator of class "DateRangeValidator"
     *     ['dateRange', 'DateRangeValidator'],
     * ];
     * ```
     *
     * Note, in order to inherit rules defined in the parent class, a child class needs to
     * merge the parent rules with child rules using functions such as `array_merge()`.
     *
     * @return array validation rules
     * @see scenarios()
     */
    public function rules()
    {
        return [];
    }

    /**
     * Returns a list of scenarios and the corresponding active attributes.
     *
     * An active attribute is one that is subject to validation in the current scenario.
     * The returned array should be in the following format:
     *
     * ```php
     * [
     *     'scenario1' => ['attribute11', 'attribute12', ...],
     *     'scenario2' => ['attribute21', 'attribute22', ...],
     *     ...
     * ]
     * ```
     *
     * By default, an active attribute is considered safe and can be massively assigned.
     * If an attribute should NOT be massively assigned (thus considered unsafe),
     * please prefix the attribute with an exclamation character (e.g. `'!rank'`).
     *
     * The default implementation of this method will return all scenarios found in the [[rules()]]
     * declaration. A special scenario named [[SCENARIO_DEFAULT]] will contain all attributes
     * found in the [[rules()]]. Each scenario will be associated with the attributes that
     * are being validated by the validation rules that apply to the scenario.
     *
     * @return array a list of scenarios and the corresponding active attributes.
     */
    public function scenarios()
    {
        $scenarios = [self::SCENARIO_DEFAULT => []];
        foreach ($this->getValidators() as $validator) {
            foreach ($validator->on as $scenario) {
                $scenarios[$scenario] = [];
            }
            foreach ($validator->except as $scenario) {
                $scenarios[$scenario] = [];
            }
        }
        $names = array_keys($scenarios);

        foreach ($this->getValidators() as $validator) {
            if (empty($validator->on) && empty($validator->except)) {
                foreach ($names as $name) {
                    foreach ($validator->attributes as $attribute) {
                        $scenarios[$name][$attribute] = true;
                    }
                }
            } elseif (empty($validator->on)) {
                foreach ($names as $name) {
                    if (!in_array($name, $validator->except, true)) {
                        foreach ($validator->attributes as $attribute) {
                            $scenarios[$name][$attribute] = true;
                        }
                    }
                }
            } else {
                foreach ($validator->on as $name) {
                    foreach ($validator->attributes as $attribute) {
                        $scenarios[$name][$attribute] = true;
                    }
                }
            }
        }

        foreach ($scenarios as $scenario => $attributes) {
            if (!empty($attributes)) {
                $scenarios[$scenario] = array_keys($attributes);
            }
        }

        return $scenarios;
    }

    /**
     * Returns the form name that this model class should use.
     *
     * The form name is mainly used by [[\yii\widgets\ActiveForm]] to determine how to name
     * the input fields for the attributes in a model. If the form name is "A" and an attribute
     * name is "b", then the corresponding input name would be "A[b]". If the form name is
     * an empty string, then the input name would be "b".
     *
     * The purpose of the above naming schema is that for forms which contain multiple different models,
     * the attributes of each model are grouped in sub-arrays of the POST-data and it is easier to
     * differentiate between them.
     *
     * By default, this method returns the model class name (without the namespace part)
     * as the form name. You may override it when the model is used in different forms.
     *
     * @return string the form name of this model class.
     * @see load()
     * @throws InvalidConfigException when form is defined with anonymous class and `formName()` method is
     * not overridden.
     */
    public function formName()
    {
        $reflector = new ReflectionClass($this);
        if (PHP_VERSION_ID >= 70000 && $reflector->isAnonymous()) {
            throw new InvalidConfigException('The "formName()" method should be explicitly defined for anonymous models');
        }
        return $reflector->getShortName();
    }

    /**
     * Returns the list of attribute names.
     * By default, this method returns all public non-static properties of the class.
     * You may override this method to change the default behavior.
     * @return array list of attribute names.
     */
    public function attributes()
    {
        $class = new ReflectionClass($this);
        $names = [];
        foreach ($class->getProperties(\ReflectionProperty::IS_PUBLIC) as $property) {
            if (!$property->isStatic()) {
                $names[] = $property->getName();
            }
        }

        return $names;
    }

    /**
     * Returns the attribute labels.
     *
     * Attribute labels are mainly used for display purpose. For example, given an attribute
     * `firstName`, we can declare a label `First Name` which is more user-friendly and can
     * be displayed to end users.
     *
     * By default an attribute label is generated using [[generateAttributeLabel()]].
     * This method allows you to explicitly specify attribute labels.
     *
     * Note, in order to inherit labels defined in the parent class, a child class needs to
     * merge the parent labels with child labels using functions such as `array_merge()`.
     *
     * @return array attribute labels (name => label)
     * @see generateAttributeLabel()
     */
    public function attributeLabels()
    {
        return [];
    }

    /**
     * Returns the attribute hints.
     *
     * Attribute hints are mainly used for display purpose. For example, given an attribute
     * `isPublic`, we can declare a hint `Whether the post should be visible for not logged in users`,
     * which provides user-friendly description of the attribute meaning and can be displayed to end users.
     *
     * Unlike label hint will not be generated, if its explicit declaration is omitted.
     *
     * Note, in order to inherit hints defined in the parent class, a child class needs to
     * merge the parent hints with child hints using functions such as `array_merge()`.
     *
     * @return array attribute hints (name => hint)
     * @since 2.0.4
     */
    public function attributeHints()
    {
        return [];
    }

    /**
     * Performs the data validation.
     *
     * This method executes the validation rules applicable to the current [[scenario]].
     * The following criteria are used to determine whether a rule is currently applicable:
     *
     * - the rule must be associated with the attributes relevant to the current scenario;
     * - the rules must be effective for the current scenario.
     *
     * This method will call [[beforeValidate()]] and [[afterValidate()]] before and
     * after the actual validation, respectively. If [[beforeValidate()]] returns false,
     * the validation will be cancelled and [[afterValidate()]] will not be called.
     *
     * Errors found during the validation can be retrieved via [[getErrors()]],
     * [[getFirstErrors()]] and [[getFirstError()]].
     *
     * @param string[]|string|null $attributeNames attribute name or list of attribute names
     * that should be validated. If this parameter is empty, it means any attribute listed in
     * the applicable validation rules should be validated.
     * @param bool $clearErrors whether to call [[clearErrors()]] before performing validation
     * @return bool whether the validation is successful without any error.
     * @throws InvalidArgumentException if the current scenario is unknown.
     */
    public function validate($attributeNames = null, $clearErrors = true)
    {
        if ($clearErrors) {
            $this->clearErrors();
        }

        if (!$this->beforeValidate()) {
            return false;
        }

        $scenarios = $this->scenarios();
        $scenario = $this->getScenario();
        if (!isset($scenarios[$scenario])) {
            throw new InvalidArgumentException("Unknown scenario: $scenario");
        }

        if ($attributeNames === null) {
            $attributeNames = $this->activeAttributes();
        }

        $attributeNames = (array)$attributeNames;

        foreach ($this->getActiveValidators() as $validator) {
            $validator->validateAttributes($this, $attributeNames);
        }
        $this->afterValidate();

        return !$this->hasErrors();
    }

    /**
     * This method is invoked before validation starts.
     * The default implementation raises a `beforeValidate` event.
     * You may override this method to do preliminary checks before validation.
     * Make sure the parent implementation is invoked so that the event can be raised.
     * @return bool whether the validation should be executed. Defaults to true.
     * If false is returned, the validation will stop and the model is considered invalid.
     */
    public function beforeValidate()
    {
        $event = new ModelEvent();
        $this->trigger(self::EVENT_BEFORE_VALIDATE, $event);

        return $event->isValid;
    }

    /**
     * This method is invoked after validation ends.
     * The default implementation raises an `afterValidate` event.
     * You may override this method to do postprocessing after validation.
     * Make sure the parent implementation is invoked so that the event can be raised.
     */
    public function afterValidate()
    {
        $this->trigger(self::EVENT_AFTER_VALIDATE);
    }

    /**
     * Returns all the validators declared in [[rules()]].
     *
     * This method differs from [[getActiveValidators()]] in that the latter
     * only returns the validators applicable to the current [[scenario]].
     *
     * Because this method returns an ArrayObject object, you may
     * manipulate it by inserting or removing validators (useful in model behaviors).
     * For example,
     *
     * ```php
     * $model->validators[] = $newValidator;
     * ```
     *
     * @return ArrayObject|\yii\validators\Validator[] all the validators declared in the model.
     */
    public function getValidators()
    {
        if ($this->_validators === null) {
            $this->_validators = $this->createValidators();
        }

        return $this->_validators;
    }

    /**
     * Returns the validators applicable to the current [[scenario]].
     * @param string|null $attribute the name of the attribute whose applicable validators should be returned.
     * If this is null, the validators for ALL attributes in the model will be returned.
     * @return \yii\validators\Validator[] the validators applicable to the current [[scenario]].
     */
    public function getActiveValidators($attribute = null)
    {
        $activeAttributes = $this->activeAttributes();
        if ($attribute !== null && !in_array($attribute, $activeAttributes, true)) {
            return [];
        }
        $scenario = $this->getScenario();
        $validators = [];
        foreach ($this->getValidators() as $validator) {
            if ($attribute === null) {
                $validatorAttributes = $validator->getValidationAttributes($activeAttributes);
                $attributeValid = !empty($validatorAttributes);
            } else {
                $attributeValid = in_array($attribute, $validator->getValidationAttributes($attribute), true);
            }
            if ($attributeValid && $validator->isActive($scenario)) {
                $validators[] = $validator;
            }
        }

        return $validators;
    }

    /**
     * Creates validator objects based on the validation rules specified in [[rules()]].
     * Unlike [[getValidators()]], each time this method is called, a new list of validators will be returned.
     * @return ArrayObject validators
     * @throws InvalidConfigException if any validation rule configuration is invalid
     */
    public function createValidators()
    {
        $validators = new ArrayObject();
        foreach ($this->rules() as $rule) {
            if ($rule instanceof Validator) {
                $validators->append($rule);
            } elseif (is_array($rule) && isset($rule[0], $rule[1])) { // attributes, validator type
                $validator = Validator::createValidator($rule[1], $this, (array) $rule[0], array_slice($rule, 2));
                $validators->append($validator);
            } else {
                throw new InvalidConfigException('Invalid validation rule: a rule must specify both attribute names and validator type.');
            }
        }

        return $validators;
    }

    /**
     * Returns a value indicating whether the attribute is required.
     * This is determined by checking if the attribute is associated with a
     * [[\yii\validators\RequiredValidator|required]] validation rule in the
     * current [[scenario]].
     *
     * Note that when the validator has a conditional validation applied using
     * [[\yii\validators\RequiredValidator::$when|$when]] this method will return
     * `false` regardless of the `when` condition because it may be called be
     * before the model is loaded with data.
     *
     * @param string $attribute attribute name
     * @return bool whether the attribute is required
     */
    public function isAttributeRequired($attribute)
    {
        foreach ($this->getActiveValidators($attribute) as $validator) {
            if ($validator instanceof RequiredValidator && $validator->when === null) {
                return true;
            }
        }

        return false;
    }

    /**
     * Returns a value indicating whether the attribute is safe for massive assignments.
     * @param string $attribute attribute name
     * @return bool whether the attribute is safe for massive assignments
     * @see safeAttributes()
     */
    public function isAttributeSafe($attribute)
    {
        return in_array($attribute, $this->safeAttributes(), true);
    }

    /**
     * Returns a value indicating whether the attribute is active in the current scenario.
     * @param string $attribute attribute name
     * @return bool whether the attribute is active in the current scenario
     * @see activeAttributes()
     */
    public function isAttributeActive($attribute)
    {
        return in_array($attribute, $this->activeAttributes(), true);
    }

    /**
     * Returns the text label for the specified attribute.
     * @param string $attribute the attribute name
     * @return string the attribute label
     * @see generateAttributeLabel()
     * @see attributeLabels()
     */
    public function getAttributeLabel($attribute)
    {
        $labels = $this->attributeLabels();
        return isset($labels[$attribute]) ? $labels[$attribute] : $this->generateAttributeLabel($attribute);
    }

    /**
     * Returns the text hint for the specified attribute.
     * @param string $attribute the attribute name
     * @return string the attribute hint
     * @see attributeHints()
     * @since 2.0.4
     */
    public function getAttributeHint($attribute)
    {
        $hints = $this->attributeHints();
        return isset($hints[$attribute]) ? $hints[$attribute] : '';
    }

    /**
     * Returns a value indicating whether there is any validation error.
     * @param string|null $attribute attribute name. Use null to check all attributes.
     * @return bool whether there is any error.
     */
    public function hasErrors($attribute = null)
    {
        return $attribute === null ? !empty($this->_errors) : isset($this->_errors[$attribute]);
    }

    /**
     * Returns the errors for all attributes or a single attribute.
     * @param string|null $attribute attribute name. Use null to retrieve errors for all attributes.
     * @return array errors for all attributes or the specified attribute. Empty array is returned if no error.
     * See [[getErrors()]] for detailed description.
     * Note that when returning errors for all attributes, the result is a two-dimensional array, like the following:
     *
     * ```php
     * [
     *     'username' => [
     *         'Username is required.',
     *         'Username must contain only word characters.',
     *     ],
     *     'email' => [
     *         'Email address is invalid.',
     *     ]
     * ]
     * ```
     *
     * @see getFirstErrors()
     * @see getFirstError()
     */
    public function getErrors($attribute = null)
    {
        if ($attribute === null) {
            return $this->_errors === null ? [] : $this->_errors;
        }

        return isset($this->_errors[$attribute]) ? $this->_errors[$attribute] : [];
    }

    /**
     * Returns the first error of every attribute in the model.
     * @return array the first errors. The array keys are the attribute names, and the array
     * values are the corresponding error messages. An empty array will be returned if there is no error.
     * @see getErrors()
     * @see getFirstError()
     */
    public function getFirstErrors()
    {
        if (empty($this->_errors)) {
            return [];
        }

        $errors = [];
        foreach ($this->_errors as $name => $es) {
            if (!empty($es)) {
                $errors[$name] = reset($es);
            }
        }

        return $errors;
    }

    /**
     * Returns the first error of the specified attribute.
     * @param string $attribute attribute name.
     * @return string|null the error message. Null is returned if no error.
     * @see getErrors()
     * @see getFirstErrors()
     */
    public function getFirstError($attribute)
    {
        return isset($this->_errors[$attribute]) ? reset($this->_errors[$attribute]) : null;
    }

    /**
     * Returns the errors for all attributes as a one-dimensional array.
     * @param bool $showAllErrors boolean, if set to true every error message for each attribute will be shown otherwise
     * only the first error message for each attribute will be shown.
     * @return array errors for all attributes as a one-dimensional array. Empty array is returned if no error.
     * @see getErrors()
     * @see getFirstErrors()
     * @since 2.0.14
     */
    public function getErrorSummary($showAllErrors)
    {
        $lines = [];
        $errors = $showAllErrors ? $this->getErrors() : $this->getFirstErrors();
        foreach ($errors as $es) {
            $lines = array_merge($lines, (array)$es);
        }
        return $lines;
    }

    /**
     * Adds a new error to the specified attribute.
     * @param string $attribute attribute name
     * @param string $error new error message
     */
    public function addError($attribute, $error = '')
    {
        $this->_errors[$attribute][] = $error;
    }

    /**
     * Adds a list of errors.
     * @param array $items a list of errors. The array keys must be attribute names.
     * The array values should be error messages. If an attribute has multiple errors,
     * these errors must be given in terms of an array.
     * You may use the result of [[getErrors()]] as the value for this parameter.
     * @since 2.0.2
     */
    public function addErrors(array $items)
    {
        foreach ($items as $attribute => $errors) {
            if (is_array($errors)) {
                foreach ($errors as $error) {
                    $this->addError($attribute, $error);
                }
            } else {
                $this->addError($attribute, $errors);
            }
        }
    }

    /**
     * Removes errors for all attributes or a single attribute.
     * @param string|null $attribute attribute name. Use null to remove errors for all attributes.
     */
    public function clearErrors($attribute = null)
    {
        if ($attribute === null) {
            $this->_errors = [];
        } else {
            unset($this->_errors[$attribute]);
        }
    }

    /**
     * Generates a user friendly attribute label based on the give attribute name.
     * This is done by replacing underscores, dashes and dots with blanks and
     * changing the first letter of each word to upper case.
     * For example, 'department_name' or 'DepartmentName' will generate 'Department Name'.
     * @param string $name the column name
     * @return string the attribute label
     */
    public function generateAttributeLabel($name)
    {
        return Inflector::camel2words($name, true);
    }

    /**
     * Returns attribute values.
     * @param array|null $names list of attributes whose value needs to be returned.
     * Defaults to null, meaning all attributes listed in [[attributes()]] will be returned.
     * If it is an array, only the attributes in the array will be returned.
     * @param array $except list of attributes whose value should NOT be returned.
     * @return array attribute values (name => value).
     */
    public function getAttributes($names = null, $except = [])
    {
        $values = [];
        if ($names === null) {
            $names = $this->attributes();
        }
        foreach ($names as $name) {
            $values[$name] = $this->$name;
        }
        foreach ($except as $name) {
            unset($values[$name]);
        }

        return $values;
    }

    /**
     * Sets the attribute values in a massive way.
     * @param array $values attribute values (name => value) to be assigned to the model.
     * @param bool $safeOnly whether the assignments should only be done to the safe attributes.
     * A safe attribute is one that is associated with a validation rule in the current [[scenario]].
     * @see safeAttributes()
     * @see attributes()
     */
    public function setAttributes($values, $safeOnly = true)
    {
        if (is_array($values)) {
            $attributes = array_flip($safeOnly ? $this->safeAttributes() : $this->attributes());
            foreach ($values as $name => $value) {
                if (isset($attributes[$name])) {
                    $this->$name = $value;
                } elseif ($safeOnly) {
                    $this->onUnsafeAttribute($name, $value);
                }
            }
        }
    }

    /**
     * This method is invoked when an unsafe attribute is being massively assigned.
     * The default implementation will log a warning message if YII_DEBUG is on.
     * It does nothing otherwise.
     * @param string $name the unsafe attribute name
     * @param mixed $value the attribute value
     */
    public function onUnsafeAttribute($name, $value)
    {
        if (YII_DEBUG) {
            Yii::debug("Failed to set unsafe attribute '$name' in '" . get_class($this) . "'.", __METHOD__);
        }
    }

    /**
     * Returns the scenario that this model is used in.
     *
     * Scenario affects how validation is performed and which attributes can
     * be massively assigned.
     *
     * @return string the scenario that this model is in. Defaults to [[SCENARIO_DEFAULT]].
     */
    public function getScenario()
    {
        return $this->_scenario;
    }

    /**
     * Sets the scenario for the model.
     * Note that this method does not check if the scenario exists or not.
     * The method [[validate()]] will perform this check.
     * @param string $value the scenario that this model is in.
     */
    public function setScenario($value)
    {
        $this->_scenario = $value;
    }

    /**
     * Returns the attribute names that are safe to be massively assigned in the current scenario.
     * @return string[] safe attribute names
     */
    public function safeAttributes()
    {
        $scenario = $this->getScenario();
        $scenarios = $this->scenarios();
        if (!isset($scenarios[$scenario])) {
            return [];
        }
        $attributes = [];
        foreach ($scenarios[$scenario] as $attribute) {
            if (strncmp($attribute, '!', 1) !== 0 && !in_array('!' . $attribute, $scenarios[$scenario])) {
                $attributes[] = $attribute;
            }
        }

        return $attributes;
    }

    /**
     * Returns the attribute names that are subject to validation in the current scenario.
     * @return string[] safe attribute names
     */
    public function activeAttributes()
    {
        $scenario = $this->getScenario();
        $scenarios = $this->scenarios();
        if (!isset($scenarios[$scenario])) {
            return [];
        }
        $attributes = array_keys(array_flip($scenarios[$scenario]));
        foreach ($attributes as $i => $attribute) {
            if (strncmp($attribute, '!', 1) === 0) {
                $attributes[$i] = substr($attribute, 1);
            }
        }

        return $attributes;
    }

    /**
     * Populates the model with input data.
     *
     * This method provides a convenient shortcut for:
     *
     * ```php
     * if (isset($_POST['FormName'])) {
     *     $model->attributes = $_POST['FormName'];
     *     if ($model->save()) {
     *         // handle success
     *     }
     * }
     * ```
     *
     * which, with `load()` can be written as:
     *
     * ```php
     * if ($model->load($_POST) && $model->save()) {
     *     // handle success
     * }
     * ```
     *
     * `load()` gets the `'FormName'` from the model's [[formName()]] method (which you may override), unless the
     * `$formName` parameter is given. If the form name is empty, `load()` populates the model with the whole of `$data`,
     * instead of `$data['FormName']`.
     *
     * Note, that the data being populated is subject to the safety check by [[setAttributes()]].
     *
     * @param array $data the data array to load, typically `$_POST` or `$_GET`.
     * @param string|null $formName the form name to use to load the data into the model, empty string when form not use.
     * If not set, [[formName()]] is used.
     * @return bool whether `load()` found the expected form in `$data`.
     */
    public function load($data, $formName = null)
    {
        $scope = $formName === null ? $this->formName() : $formName;
        if ($scope === '' && !empty($data)) {
            $this->setAttributes($data);

            return true;
        } elseif (isset($data[$scope])) {
            $this->setAttributes($data[$scope]);

            return true;
        }

        return false;
    }

    /**
     * Populates a set of models with the data from end user.
     * This method is mainly used to collect tabular data input.
     * The data to be loaded for each model is `$data[formName][index]`, where `formName`
     * refers to the value of [[formName()]], and `index` the index of the model in the `$models` array.
     * If [[formName()]] is empty, `$data[index]` will be used to populate each model.
     * The data being populated to each model is subject to the safety check by [[setAttributes()]].
     * @param array $models the models to be populated. Note that all models should have the same class.
     * @param array $data the data array. This is usually `$_POST` or `$_GET`, but can also be any valid array
     * supplied by end user.
     * @param string|null $formName the form name to be used for loading the data into the models.
     * If not set, it will use the [[formName()]] value of the first model in `$models`.
     * This parameter is available since version 2.0.1.
     * @return bool whether at least one of the models is successfully populated.
     */
    public static function loadMultiple($models, $data, $formName = null)
    {
        if ($formName === null) {
            /* @var $first Model|false */
            $first = reset($models);
            if ($first === false) {
                return false;
            }
            $formName = $first->formName();
        }

        $success = false;
        foreach ($models as $i => $model) {
            /* @var $model Model */
            if ($formName == '') {
                if (!empty($data[$i]) && $model->load($data[$i], '')) {
                    $success = true;
                }
            } elseif (!empty($data[$formName][$i]) && $model->load($data[$formName][$i], '')) {
                $success = true;
            }
        }

        return $success;
    }

    /**
     * Validates multiple models.
     * This method will validate every model. The models being validated may
     * be of the same or different types.
     * @param array $models the models to be validated
     * @param array|null $attributeNames list of attribute names that should be validated.
     * If this parameter is empty, it means any attribute listed in the applicable
     * validation rules should be validated.
     * @return bool whether all models are valid. False will be returned if one
     * or multiple models have validation error.
     */
    public static function validateMultiple($models, $attributeNames = null)
    {
        $valid = true;
        /* @var $model Model */
        foreach ($models as $model) {
            $valid = $model->validate($attributeNames) && $valid;
        }

        return $valid;
    }

    /**
     * Returns the list of fields that should be returned by default by [[toArray()]] when no specific fields are specified.
     *
     * A field is a named element in the returned array by [[toArray()]].
     *
     * This method should return an array of field names or field definitions.
     * If the former, the field name will be treated as an object property name whose value will be used
     * as the field value. If the latter, the array key should be the field name while the array value should be
     * the corresponding field definition which can be either an object property name or a PHP callable
     * returning the corresponding field value. The signature of the callable should be:
     *
     * ```php
     * function ($model, $field) {
     *     // return field value
     * }
     * ```
     *
     * For example, the following code declares four fields:
     *
     * - `email`: the field name is the same as the property name `email`;
     * - `firstName` and `lastName`: the field names are `firstName` and `lastName`, and their
     *   values are obtained from the `first_name` and `last_name` properties;
     * - `fullName`: the field name is `fullName`. Its value is obtained by concatenating `first_name`
     *   and `last_name`.
     *
     * ```php
     * return [
     *     'email',
     *     'firstName' => 'first_name',
     *     'lastName' => 'last_name',
     *     'fullName' => function ($model) {
     *         return $model->first_name . ' ' . $model->last_name;
     *     },
     * ];
     * ```
     *
     * In this method, you may also want to return different lists of fields based on some context
     * information. For example, depending on [[scenario]] or the privilege of the current application user,
     * you may return different sets of visible fields or filter out some fields.
     *
     * The default implementation of this method returns [[attributes()]] indexed by the same attribute names.
     *
     * @return array the list of field names or field definitions.
     * @see toArray()
     */
    public function fields()
    {
        $fields = $this->attributes();

        return array_combine($fields, $fields);
    }

    /**
     * Returns an iterator for traversing the attributes in the model.
     * This method is required by the interface [[\IteratorAggregate]].
     * @return ArrayIterator an iterator for traversing the items in the list.
     */
    #[\ReturnTypeWillChange]
    public function getIterator()
    {
        $attributes = $this->getAttributes();
        return new ArrayIterator($attributes);
    }

    /**
     * Returns whether there is an element at the specified offset.
     * This method is required by the SPL interface [[\ArrayAccess]].
     * It is implicitly called when you use something like `isset($model[$offset])`.
     * @param string $offset the offset to check on.
     * @return bool whether or not an offset exists.
     */
    #[\ReturnTypeWillChange]
    public function offsetExists($offset)
    {
        return isset($this->$offset);
    }

    /**
     * Returns the element at the specified offset.
     * This method is required by the SPL interface [[\ArrayAccess]].
     * It is implicitly called when you use something like `$value = $model[$offset];`.
     * @param string $offset the offset to retrieve element.
     * @return mixed the element at the offset, null if no element is found at the offset
     */
    #[\ReturnTypeWillChange]
    public function offsetGet($offset)
    {
        return $this->$offset;
    }

    /**
     * Sets the element at the specified offset.
     * This method is required by the SPL interface [[\ArrayAccess]].
     * It is implicitly called when you use something like `$model[$offset] = $value;`.
     * @param string $offset the offset to set element
     * @param mixed $value the element value
     */
    #[\ReturnTypeWillChange]
    public function offsetSet($offset, $value)
    {
        $this->$offset = $value;
    }

    /**
     * Sets the element value at the specified offset to null.
     * This method is required by the SPL interface [[\ArrayAccess]].
     * It is implicitly called when you use something like `unset($model[$offset])`.
     * @param string $offset the offset to unset element
     */
    #[\ReturnTypeWillChange]
    public function offsetUnset($offset)
    {
        $this->$offset = null;
    }
}

<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\db;

use Yii;
use yii\base\InvalidArgumentException;
use yii\base\InvalidCallException;
use yii\base\InvalidConfigException;
use yii\base\InvalidParamException;
use yii\base\Model;
use yii\base\ModelEvent;
use yii\base\NotSupportedException;
use yii\base\UnknownMethodException;
use yii\helpers\ArrayHelper;

/**
 * ActiveRecord is the base class for classes representing relational data in terms of objects.
 *
 * See [[\yii\db\ActiveRecord]] for a concrete implementation.
 *
 * @property-read array $dirtyAttributes The changed attribute values (name-value pairs).
 * @property bool $isNewRecord Whether the record is new and should be inserted when calling [[save()]].
 * @property array $oldAttributes The old attribute values (name-value pairs). Note that the type of this
 * property differs in getter and setter. See [[getOldAttributes()]] and [[setOldAttributes()]] for details.
 * @property-read mixed $oldPrimaryKey The old primary key value. An array (column name => column value) is
 * returned if the primary key is composite. A string is returned otherwise (null will be returned if the key
 * value is null).
 * @property-read mixed $primaryKey The primary key value. An array (column name => column value) is returned
 * if the primary key is composite. A string is returned otherwise (null will be returned if the key value is
 * null).
 * @property-read array $relatedRecords An array of related records indexed by relation names.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @author Carsten Brandt <mail@cebe.cc>
 * @since 2.0
 */
abstract class BaseActiveRecord extends Model implements ActiveRecordInterface
{
    /**
     * @event Event an event that is triggered when the record is initialized via [[init()]].
     */
    const EVENT_INIT = 'init';
    /**
     * @event Event an event that is triggered after the record is created and populated with query result.
     */
    const EVENT_AFTER_FIND = 'afterFind';
    /**
     * @event ModelEvent an event that is triggered before inserting a record.
     * You may set [[ModelEvent::isValid]] to be `false` to stop the insertion.
     */
    const EVENT_BEFORE_INSERT = 'beforeInsert';
    /**
     * @event AfterSaveEvent an event that is triggered after a record is inserted.
     */
    const EVENT_AFTER_INSERT = 'afterInsert';
    /**
     * @event ModelEvent an event that is triggered before updating a record.
     * You may set [[ModelEvent::isValid]] to be `false` to stop the update.
     */
    const EVENT_BEFORE_UPDATE = 'beforeUpdate';
    /**
     * @event AfterSaveEvent an event that is triggered after a record is updated.
     */
    const EVENT_AFTER_UPDATE = 'afterUpdate';
    /**
     * @event ModelEvent an event that is triggered before deleting a record.
     * You may set [[ModelEvent::isValid]] to be `false` to stop the deletion.
     */
    const EVENT_BEFORE_DELETE = 'beforeDelete';
    /**
     * @event Event an event that is triggered after a record is deleted.
     */
    const EVENT_AFTER_DELETE = 'afterDelete';
    /**
     * @event Event an event that is triggered after a record is refreshed.
     * @since 2.0.8
     */
    const EVENT_AFTER_REFRESH = 'afterRefresh';

    /**
     * @var array attribute values indexed by attribute names
     */
    private $_attributes = [];
    /**
     * @var array|null old attribute values indexed by attribute names.
     * This is `null` if the record [[isNewRecord|is new]].
     */
    private $_oldAttributes;
    /**
     * @var array related models indexed by the relation names
     */
    private $_related = [];
    /**
     * @var array relation names indexed by their link attributes
     */
    private $_relationsDependencies = [];


    /**
     * {@inheritdoc}
     * @return static|null ActiveRecord instance matching the condition, or `null` if nothing matches.
     */
    public static function findOne($condition)
    {
        return static::findByCondition($condition)->one();
    }

    /**
     * {@inheritdoc}
     * @return static[] an array of ActiveRecord instances, or an empty array if nothing matches.
     */
    public static function findAll($condition)
    {
        return static::findByCondition($condition)->all();
    }

    /**
     * Finds ActiveRecord instance(s) by the given condition.
     * This method is internally called by [[findOne()]] and [[findAll()]].
     * @param mixed $condition please refer to [[findOne()]] for the explanation of this parameter
     * @return ActiveQueryInterface the newly created [[ActiveQueryInterface|ActiveQuery]] instance.
     * @throws InvalidConfigException if there is no primary key defined
     * @internal
     */
    protected static function findByCondition($condition)
    {
        $query = static::find();

        if (!ArrayHelper::isAssociative($condition) && !$condition instanceof ExpressionInterface) {
            // query by primary key
            $primaryKey = static::primaryKey();
            if (isset($primaryKey[0])) {
                // if condition is scalar, search for a single primary key, if it is array, search for multiple primary key values
                $condition = [$primaryKey[0] => is_array($condition) ? array_values($condition) : $condition];
            } else {
                throw new InvalidConfigException('"' . get_called_class() . '" must have a primary key.');
            }
        }

        return $query->andWhere($condition);
    }

    /**
     * Updates the whole table using the provided attribute values and conditions.
     *
     * For example, to change the status to be 1 for all customers whose status is 2:
     *
     * ```php
     * Customer::updateAll(['status' => 1], 'status = 2');
     * ```
     *
     * @param array $attributes attribute values (name-value pairs) to be saved into the table
     * @param string|array $condition the conditions that will be put in the WHERE part of the UPDATE SQL.
     * Please refer to [[Query::where()]] on how to specify this parameter.
     * @return int the number of rows updated
     * @throws NotSupportedException if not overridden
     */
    public static function updateAll($attributes, $condition = '')
    {
        throw new NotSupportedException(__METHOD__ . ' is not supported.');
    }

    /**
     * Updates the whole table using the provided counter changes and conditions.
     *
     * For example, to increment all customers' age by 1,
     *
     * ```php
     * Customer::updateAllCounters(['age' => 1]);
     * ```
     *
     * @param array $counters the counters to be updated (attribute name => increment value).
     * Use negative values if you want to decrement the counters.
     * @param string|array $condition the conditions that will be put in the WHERE part of the UPDATE SQL.
     * Please refer to [[Query::where()]] on how to specify this parameter.
     * @return int the number of rows updated
     * @throws NotSupportedException if not overrided
     */
    public static function updateAllCounters($counters, $condition = '')
    {
        throw new NotSupportedException(__METHOD__ . ' is not supported.');
    }

    /**
     * Deletes rows in the table using the provided conditions.
     * WARNING: If you do not specify any condition, this method will delete ALL rows in the table.
     *
     * For example, to delete all customers whose status is 3:
     *
     * ```php
     * Customer::deleteAll('status = 3');
     * ```
     *
     * @param string|array $condition the conditions that will be put in the WHERE part of the DELETE SQL.
     * Please refer to [[Query::where()]] on how to specify this parameter.
     * @return int the number of rows deleted
     * @throws NotSupportedException if not overridden.
     */
    public static function deleteAll($condition = null)
    {
        throw new NotSupportedException(__METHOD__ . ' is not supported.');
    }

    /**
     * Returns the name of the column that stores the lock version for implementing optimistic locking.
     *
     * Optimistic locking allows multiple users to access the same record for edits and avoids
     * potential conflicts. In case when a user attempts to save the record upon some staled data
     * (because another user has modified the data), a [[StaleObjectException]] exception will be thrown,
     * and the update or deletion is skipped.
     *
     * Optimistic locking is only supported by [[update()]] and [[delete()]].
     *
     * To use Optimistic locking:
     *
     * 1. Create a column to store the version number of each row. The column type should be `BIGINT DEFAULT 0`.
     *    Override this method to return the name of this column.
     * 2. Ensure the version value is submitted and loaded to your model before any update or delete.
     *    Or add [[\yii\behaviors\OptimisticLockBehavior|OptimisticLockBehavior]] to your model
     *    class in order to automate the process.
     * 3. In the Web form that collects the user input, add a hidden field that stores
     *    the lock version of the record being updated.
     * 4. In the controller action that does the data updating, try to catch the [[StaleObjectException]]
     *    and implement necessary business logic (e.g. merging the changes, prompting stated data)
     *    to resolve the conflict.
     *
     * @return string the column name that stores the lock version of a table row.
     * If `null` is returned (default implemented), optimistic locking will not be supported.
     */
    public function optimisticLock()
    {
        return null;
    }

    /**
     * {@inheritdoc}
     */
    public function canGetProperty($name, $checkVars = true, $checkBehaviors = true)
    {
        if (parent::canGetProperty($name, $checkVars, $checkBehaviors)) {
            return true;
        }

        try {
            return $this->hasAttribute($name);
        } catch (\Exception $e) {
            // `hasAttribute()` may fail on base/abstract classes in case automatic attribute list fetching used
            return false;
        }
    }

    /**
     * {@inheritdoc}
     */
    public function canSetProperty($name, $checkVars = true, $checkBehaviors = true)
    {
        if (parent::canSetProperty($name, $checkVars, $checkBehaviors)) {
            return true;
        }

        try {
            return $this->hasAttribute($name);
        } catch (\Exception $e) {
            // `hasAttribute()` may fail on base/abstract classes in case automatic attribute list fetching used
            return false;
        }
    }

    /**
     * PHP getter magic method.
     * This method is overridden so that attributes and related objects can be accessed like properties.
     *
     * @param string $name property name
     * @throws InvalidArgumentException if relation name is wrong
     * @return mixed property value
     * @see getAttribute()
     */
    public function __get($name)
    {
        if (isset($this->_attributes[$name]) || array_key_exists($name, $this->_attributes)) {
            return $this->_attributes[$name];
        }

        if ($this->hasAttribute($name)) {
            return null;
        }

        if (isset($this->_related[$name]) || array_key_exists($name, $this->_related)) {
            return $this->_related[$name];
        }
        $value = parent::__get($name);
        if ($value instanceof ActiveQueryInterface) {
            $this->setRelationDependencies($name, $value);
            return $this->_related[$name] = $value->findFor($name, $this);
        }

        return $value;
    }

    /**
     * PHP setter magic method.
     * This method is overridden so that AR attributes can be accessed like properties.
     * @param string $name property name
     * @param mixed $value property value
     */
    public function __set($name, $value)
    {
        if ($this->hasAttribute($name)) {
            if (
                !empty($this->_relationsDependencies[$name])
                && (!array_key_exists($name, $this->_attributes) || $this->_attributes[$name] !== $value)
            ) {
                $this->resetDependentRelations($name);
            }
            $this->_attributes[$name] = $value;
        } else {
            parent::__set($name, $value);
        }
    }

    /**
     * Checks if a property value is null.
     * This method overrides the parent implementation by checking if the named attribute is `null` or not.
     * @param string $name the property name or the event name
     * @return bool whether the property value is null
     */
    public function __isset($name)
    {
        try {
            return $this->__get($name) !== null;
        } catch (\Exception $t) {
            return false;
        } catch (\Throwable $e) {
            return false;
        }
    }

    /**
     * Sets a component property to be null.
     * This method overrides the parent implementation by clearing
     * the specified attribute value.
     * @param string $name the property name or the event name
     */
    public function __unset($name)
    {
        if ($this->hasAttribute($name)) {
            unset($this->_attributes[$name]);
            if (!empty($this->_relationsDependencies[$name])) {
                $this->resetDependentRelations($name);
            }
        } elseif (array_key_exists($name, $this->_related)) {
            unset($this->_related[$name]);
        } elseif ($this->getRelation($name, false) === null) {
            parent::__unset($name);
        }
    }

    /**
     * Declares a `has-one` relation.
     * The declaration is returned in terms of a relational [[ActiveQuery]] instance
     * through which the related record can be queried and retrieved back.
     *
     * A `has-one` relation means that there is at most one related record matching
     * the criteria set by this relation, e.g., a customer has one country.
     *
     * For example, to declare the `country` relation for `Customer` class, we can write
     * the following code in the `Customer` class:
     *
     * ```php
     * public function getCountry()
     * {
     *     return $this->hasOne(Country::class, ['id' => 'country_id']);
     * }
     * ```
     *
     * Note that in the above, the 'id' key in the `$link` parameter refers to an attribute name
     * in the related class `Country`, while the 'country_id' value refers to an attribute name
     * in the current AR class.
     *
     * Call methods declared in [[ActiveQuery]] to further customize the relation.
     *
     * @param string $class the class name of the related record
     * @param array $link the primary-foreign key constraint. The keys of the array refer to
     * the attributes of the record associated with the `$class` model, while the values of the
     * array refer to the corresponding attributes in **this** AR class.
     * @return ActiveQueryInterface the relational query object.
     */
    public function hasOne($class, $link)
    {
        return $this->createRelationQuery($class, $link, false);
    }

    /**
     * Declares a `has-many` relation.
     * The declaration is returned in terms of a relational [[ActiveQuery]] instance
     * through which the related record can be queried and retrieved back.
     *
     * A `has-many` relation means that there are multiple related records matching
     * the criteria set by this relation, e.g., a customer has many orders.
     *
     * For example, to declare the `orders` relation for `Customer` class, we can write
     * the following code in the `Customer` class:
     *
     * ```php
     * public function getOrders()
     * {
     *     return $this->hasMany(Order::class, ['customer_id' => 'id']);
     * }
     * ```
     *
     * Note that in the above, the 'customer_id' key in the `$link` parameter refers to
     * an attribute name in the related class `Order`, while the 'id' value refers to
     * an attribute name in the current AR class.
     *
     * Call methods declared in [[ActiveQuery]] to further customize the relation.
     *
     * @param string $class the class name of the related record
     * @param array $link the primary-foreign key constraint. The keys of the array refer to
     * the attributes of the record associated with the `$class` model, while the values of the
     * array refer to the corresponding attributes in **this** AR class.
     * @return ActiveQueryInterface the relational query object.
     */
    public function hasMany($class, $link)
    {
        return $this->createRelationQuery($class, $link, true);
    }

    /**
     * Creates a query instance for `has-one` or `has-many` relation.
     * @param string $class the class name of the related record.
     * @param array $link the primary-foreign key constraint.
     * @param bool $multiple whether this query represents a relation to more than one record.
     * @return ActiveQueryInterface the relational query object.
     * @since 2.0.12
     * @see hasOne()
     * @see hasMany()
     */
    protected function createRelationQuery($class, $link, $multiple)
    {
        /* @var $class ActiveRecordInterface */
        /* @var $query ActiveQuery */
        $query = $class::find();
        $query->primaryModel = $this;
        $query->link = $link;
        $query->multiple = $multiple;
        return $query;
    }

    /**
     * Populates the named relation with the related records.
     * Note that this method does not check if the relation exists or not.
     * @param string $name the relation name, e.g. `orders` for a relation defined via `getOrders()` method (case-sensitive).
     * @param ActiveRecordInterface|array|null $records the related records to be populated into the relation.
     * @see getRelation()
     */
    public function populateRelation($name, $records)
    {
        foreach ($this->_relationsDependencies as &$relationNames) {
            unset($relationNames[$name]);
        }

        $this->_related[$name] = $records;
    }

    /**
     * Check whether the named relation has been populated with records.
     * @param string $name the relation name, e.g. `orders` for a relation defined via `getOrders()` method (case-sensitive).
     * @return bool whether relation has been populated with records.
     * @see getRelation()
     */
    public function isRelationPopulated($name)
    {
        return array_key_exists($name, $this->_related);
    }

    /**
     * Returns all populated related records.
     * @return array an array of related records indexed by relation names.
     * @see getRelation()
     */
    public function getRelatedRecords()
    {
        return $this->_related;
    }

    /**
     * Returns a value indicating whether the model has an attribute with the specified name.
     * @param string $name the name of the attribute
     * @return bool whether the model has an attribute with the specified name.
     */
    public function hasAttribute($name)
    {
        return isset($this->_attributes[$name]) || in_array($name, $this->attributes(), true);
    }

    /**
     * Returns the named attribute value.
     * If this record is the result of a query and the attribute is not loaded,
     * `null` will be returned.
     * @param string $name the attribute name
     * @return mixed the attribute value. `null` if the attribute is not set or does not exist.
     * @see hasAttribute()
     */
    public function getAttribute($name)
    {
        return isset($this->_attributes[$name]) ? $this->_attributes[$name] : null;
    }

    /**
     * Sets the named attribute value.
     * @param string $name the attribute name
     * @param mixed $value the attribute value.
     * @throws InvalidArgumentException if the named attribute does not exist.
     * @see hasAttribute()
     */
    public function setAttribute($name, $value)
    {
        if ($this->hasAttribute($name)) {
            if (
                !empty($this->_relationsDependencies[$name])
                && (!array_key_exists($name, $this->_attributes) || $this->_attributes[$name] !== $value)
            ) {
                $this->resetDependentRelations($name);
            }
            $this->_attributes[$name] = $value;
        } else {
            throw new InvalidArgumentException(get_class($this) . ' has no attribute named "' . $name . '".');
        }
    }

    /**
     * Returns the old attribute values.
     * @return array the old attribute values (name-value pairs)
     */
    public function getOldAttributes()
    {
        return $this->_oldAttributes === null ? [] : $this->_oldAttributes;
    }

    /**
     * Sets the old attribute values.
     * All existing old attribute values will be discarded.
     * @param array|null $values old attribute values to be set.
     * If set to `null` this record is considered to be [[isNewRecord|new]].
     */
    public function setOldAttributes($values)
    {
        $this->_oldAttributes = $values;
    }

    /**
     * Returns the old value of the named attribute.
     * If this record is the result of a query and the attribute is not loaded,
     * `null` will be returned.
     * @param string $name the attribute name
     * @return mixed the old attribute value. `null` if the attribute is not loaded before
     * or does not exist.
     * @see hasAttribute()
     */
    public function getOldAttribute($name)
    {
        return isset($this->_oldAttributes[$name]) ? $this->_oldAttributes[$name] : null;
    }

    /**
     * Sets the old value of the named attribute.
     * @param string $name the attribute name
     * @param mixed $value the old attribute value.
     * @throws InvalidArgumentException if the named attribute does not exist.
     * @see hasAttribute()
     */
    public function setOldAttribute($name, $value)
    {
        if (isset($this->_oldAttributes[$name]) || $this->hasAttribute($name)) {
            $this->_oldAttributes[$name] = $value;
        } else {
            throw new InvalidArgumentException(get_class($this) . ' has no attribute named "' . $name . '".');
        }
    }

    /**
     * Marks an attribute dirty.
     * This method may be called to force updating a record when calling [[update()]],
     * even if there is no change being made to the record.
     * @param string $name the attribute name
     */
    public function markAttributeDirty($name)
    {
        unset($this->_oldAttributes[$name]);
    }

    /**
     * Returns a value indicating whether the named attribute has been changed.
     * @param string $name the name of the attribute.
     * @param bool $identical whether the comparison of new and old value is made for
     * identical values using `===`, defaults to `true`. Otherwise `==` is used for comparison.
     * This parameter is available since version 2.0.4.
     * @return bool whether the attribute has been changed
     */
    public function isAttributeChanged($name, $identical = true)
    {
        if (isset($this->_attributes[$name], $this->_oldAttributes[$name])) {
            if ($identical) {
                return $this->_attributes[$name] !== $this->_oldAttributes[$name];
            }

            return $this->_attributes[$name] != $this->_oldAttributes[$name];
        }

        return isset($this->_attributes[$name]) || isset($this->_oldAttributes[$name]);
    }

    /**
     * Returns the attribute values that have been modified since they are loaded or saved most recently.
     *
     * The comparison of new and old values is made for identical values using `===`.
     *
     * @param string[]|null $names the names of the attributes whose values may be returned if they are
     * changed recently. If null, [[attributes()]] will be used.
     * @return array the changed attribute values (name-value pairs)
     */
    public function getDirtyAttributes($names = null)
    {
        if ($names === null) {
            $names = $this->attributes();
        }
        $names = array_flip($names);
        $attributes = [];
        if ($this->_oldAttributes === null) {
            foreach ($this->_attributes as $name => $value) {
                if (isset($names[$name])) {
                    $attributes[$name] = $value;
                }
            }
        } else {
            foreach ($this->_attributes as $name => $value) {
                if (isset($names[$name]) && (!array_key_exists($name, $this->_oldAttributes) || $value !== $this->_oldAttributes[$name])) {
                    $attributes[$name] = $value;
                }
            }
        }

        return $attributes;
    }

    /**
     * Saves the current record.
     *
     * This method will call [[insert()]] when [[isNewRecord]] is `true`, or [[update()]]
     * when [[isNewRecord]] is `false`.
     *
     * For example, to save a customer record:
     *
     * ```php
     * $customer = new Customer; // or $customer = Customer::findOne($id);
     * $customer->name = $name;
     * $customer->email = $email;
     * $customer->save();
     * ```
     *
     * @param bool $runValidation whether to perform validation (calling [[validate()]])
     * before saving the record. Defaults to `true`. If the validation fails, the record
     * will not be saved to the database and this method will return `false`.
     * @param array $attributeNames list of attribute names that need to be saved. Defaults to null,
     * meaning all attributes that are loaded from DB will be saved.
     * @return bool whether the saving succeeded (i.e. no validation errors occurred).
     */
    public function save($runValidation = true, $attributeNames = null)
    {
        if ($this->getIsNewRecord()) {
            return $this->insert($runValidation, $attributeNames);
        }

        return $this->update($runValidation, $attributeNames) !== false;
    }

    /**
     * Saves the changes to this active record into the associated database table.
     *
     * This method performs the following steps in order:
     *
     * 1. call [[beforeValidate()]] when `$runValidation` is `true`. If [[beforeValidate()]]
     *    returns `false`, the rest of the steps will be skipped;
     * 2. call [[afterValidate()]] when `$runValidation` is `true`. If validation
     *    failed, the rest of the steps will be skipped;
     * 3. call [[beforeSave()]]. If [[beforeSave()]] returns `false`,
     *    the rest of the steps will be skipped;
     * 4. save the record into database. If this fails, it will skip the rest of the steps;
     * 5. call [[afterSave()]];
     *
     * In the above step 1, 2, 3 and 5, events [[EVENT_BEFORE_VALIDATE]],
     * [[EVENT_AFTER_VALIDATE]], [[EVENT_BEFORE_UPDATE]], and [[EVENT_AFTER_UPDATE]]
     * will be raised by the corresponding methods.
     *
     * Only the [[dirtyAttributes|changed attribute values]] will be saved into database.
     *
     * For example, to update a customer record:
     *
     * ```php
     * $customer = Customer::findOne($id);
     * $customer->name = $name;
     * $customer->email = $email;
     * $customer->update();
     * ```
     *
     * Note that it is possible the update does not affect any row in the table.
     * In this case, this method will return 0. For this reason, you should use the following
     * code to check if update() is successful or not:
     *
     * ```php
     * if ($customer->update() !== false) {
     *     // update successful
     * } else {
     *     // update failed
     * }
     * ```
     *
     * @param bool $runValidation whether to perform validation (calling [[validate()]])
     * before saving the record. Defaults to `true`. If the validation fails, the record
     * will not be saved to the database and this method will return `false`.
     * @param array $attributeNames list of attribute names that need to be saved. Defaults to null,
     * meaning all attributes that are loaded from DB will be saved.
     * @return int|false the number of rows affected, or `false` if validation fails
     * or [[beforeSave()]] stops the updating process.
     * @throws StaleObjectException if [[optimisticLock|optimistic locking]] is enabled and the data
     * being updated is outdated.
     * @throws Exception in case update failed.
     */
    public function update($runValidation = true, $attributeNames = null)
    {
        if ($runValidation && !$this->validate($attributeNames)) {
            return false;
        }

        return $this->updateInternal($attributeNames);
    }

    /**
     * Updates the specified attributes.
     *
     * This method is a shortcut to [[update()]] when data validation is not needed
     * and only a small set attributes need to be updated.
     *
     * You may specify the attributes to be updated as name list or name-value pairs.
     * If the latter, the corresponding attribute values will be modified accordingly.
     * The method will then save the specified attributes into database.
     *
     * Note that this method will **not** perform data validation and will **not** trigger events.
     *
     * @param array $attributes the attributes (names or name-value pairs) to be updated
     * @return int the number of rows affected.
     */
    public function updateAttributes($attributes)
    {
        $attrs = [];
        foreach ($attributes as $name => $value) {
            if (is_int($name)) {
                $attrs[] = $value;
            } else {
                $this->$name = $value;
                $attrs[] = $name;
            }
        }

        $values = $this->getDirtyAttributes($attrs);
        if (empty($values) || $this->getIsNewRecord()) {
            return 0;
        }

        $rows = static::updateAll($values, $this->getOldPrimaryKey(true));

        foreach ($values as $name => $value) {
            $this->_oldAttributes[$name] = $this->_attributes[$name];
        }

        return $rows;
    }

    /**
     * @see update()
     * @param array $attributes attributes to update
     * @return int|false the number of rows affected, or false if [[beforeSave()]] stops the updating process.
     * @throws StaleObjectException
     */
    protected function updateInternal($attributes = null)
    {
        if (!$this->beforeSave(false)) {
            return false;
        }
        $values = $this->getDirtyAttributes($attributes);
        if (empty($values)) {
            $this->afterSave(false, $values);
            return 0;
        }
        $condition = $this->getOldPrimaryKey(true);
        $lock = $this->optimisticLock();
        if ($lock !== null) {
            $values[$lock] = $this->$lock + 1;
            $condition[$lock] = $this->$lock;
        }
        // We do not check the return value of updateAll() because it's possible
        // that the UPDATE statement doesn't change anything and thus returns 0.
        $rows = static::updateAll($values, $condition);

        if ($lock !== null && !$rows) {
            throw new StaleObjectException('The object being updated is outdated.');
        }

        if (isset($values[$lock])) {
            $this->$lock = $values[$lock];
        }

        $changedAttributes = [];
        foreach ($values as $name => $value) {
            $changedAttributes[$name] = isset($this->_oldAttributes[$name]) ? $this->_oldAttributes[$name] : null;
            $this->_oldAttributes[$name] = $value;
        }
        $this->afterSave(false, $changedAttributes);

        return $rows;
    }

    /**
     * Updates one or several counter columns for the current AR object.
     * Note that this method differs from [[updateAllCounters()]] in that it only
     * saves counters for the current AR object.
     *
     * An example usage is as follows:
     *
     * ```php
     * $post = Post::findOne($id);
     * $post->updateCounters(['view_count' => 1]);
     * ```
     *
     * @param array $counters the counters to be updated (attribute name => increment value)
     * Use negative values if you want to decrement the counters.
     * @return bool whether the saving is successful
     * @see updateAllCounters()
     */
    public function updateCounters($counters)
    {
        if (static::updateAllCounters($counters, $this->getOldPrimaryKey(true)) > 0) {
            foreach ($counters as $name => $value) {
                if (!isset($this->_attributes[$name])) {
                    $this->_attributes[$name] = $value;
                } else {
                    $this->_attributes[$name] += $value;
                }
                $this->_oldAttributes[$name] = $this->_attributes[$name];
            }

            return true;
        }

        return false;
    }

    /**
     * Deletes the table row corresponding to this active record.
     *
     * This method performs the following steps in order:
     *
     * 1. call [[beforeDelete()]]. If the method returns `false`, it will skip the
     *    rest of the steps;
     * 2. delete the record from the database;
     * 3. call [[afterDelete()]].
     *
     * In the above step 1 and 3, events named [[EVENT_BEFORE_DELETE]] and [[EVENT_AFTER_DELETE]]
     * will be raised by the corresponding methods.
     *
     * @return int|false the number of rows deleted, or `false` if the deletion is unsuccessful for some reason.
     * Note that it is possible the number of rows deleted is 0, even though the deletion execution is successful.
     * @throws StaleObjectException if [[optimisticLock|optimistic locking]] is enabled and the data
     * being deleted is outdated.
     * @throws Exception in case delete failed.
     */
    public function delete()
    {
        $result = false;
        if ($this->beforeDelete()) {
            // we do not check the return value of deleteAll() because it's possible
            // the record is already deleted in the database and thus the method will return 0
            $condition = $this->getOldPrimaryKey(true);
            $lock = $this->optimisticLock();
            if ($lock !== null) {
                $condition[$lock] = $this->$lock;
            }
            $result = static::deleteAll($condition);
            if ($lock !== null && !$result) {
                throw new StaleObjectException('The object being deleted is outdated.');
            }
            $this->_oldAttributes = null;
            $this->afterDelete();
        }

        return $result;
    }

    /**
     * Returns a value indicating whether the current record is new.
     * @return bool whether the record is new and should be inserted when calling [[save()]].
     */
    public function getIsNewRecord()
    {
        return $this->_oldAttributes === null;
    }

    /**
     * Sets the value indicating whether the record is new.
     * @param bool $value whether the record is new and should be inserted when calling [[save()]].
     * @see getIsNewRecord()
     */
    public function setIsNewRecord($value)
    {
        $this->_oldAttributes = $value ? null : $this->_attributes;
    }

    /**
     * Initializes the object.
     * This method is called at the end of the constructor.
     * The default implementation will trigger an [[EVENT_INIT]] event.
     */
    public function init()
    {
        parent::init();
        $this->trigger(self::EVENT_INIT);
    }

    /**
     * This method is called when the AR object is created and populated with the query result.
     * The default implementation will trigger an [[EVENT_AFTER_FIND]] event.
     * When overriding this method, make sure you call the parent implementation to ensure the
     * event is triggered.
     */
    public function afterFind()
    {
        $this->trigger(self::EVENT_AFTER_FIND);
    }

    /**
     * This method is called at the beginning of inserting or updating a record.
     *
     * The default implementation will trigger an [[EVENT_BEFORE_INSERT]] event when `$insert` is `true`,
     * or an [[EVENT_BEFORE_UPDATE]] event if `$insert` is `false`.
     * When overriding this method, make sure you call the parent implementation like the following:
     *
     * ```php
     * public function beforeSave($insert)
     * {
     *     if (!parent::beforeSave($insert)) {
     *         return false;
     *     }
     *
     *     // ...custom code here...
     *     return true;
     * }
     * ```
     *
     * @param bool $insert whether this method called while inserting a record.
     * If `false`, it means the method is called while updating a record.
     * @return bool whether the insertion or updating should continue.
     * If `false`, the insertion or updating will be cancelled.
     */
    public function beforeSave($insert)
    {
        $event = new ModelEvent();
        $this->trigger($insert ? self::EVENT_BEFORE_INSERT : self::EVENT_BEFORE_UPDATE, $event);

        return $event->isValid;
    }

    /**
     * This method is called at the end of inserting or updating a record.
     * The default implementation will trigger an [[EVENT_AFTER_INSERT]] event when `$insert` is `true`,
     * or an [[EVENT_AFTER_UPDATE]] event if `$insert` is `false`. The event class used is [[AfterSaveEvent]].
     * When overriding this method, make sure you call the parent implementation so that
     * the event is triggered.
     * @param bool $insert whether this method called while inserting a record.
     * If `false`, it means the method is called while updating a record.
     * @param array $changedAttributes The old values of attributes that had changed and were saved.
     * You can use this parameter to take action based on the changes made for example send an email
     * when the password had changed or implement audit trail that tracks all the changes.
     * `$changedAttributes` gives you the old attribute values while the active record (`$this`) has
     * already the new, updated values.
     *
     * Note that no automatic type conversion performed by default. You may use
     * [[\yii\behaviors\AttributeTypecastBehavior]] to facilitate attribute typecasting.
     * See http://www.yiiframework.com/doc-2.0/guide-db-active-record.html#attributes-typecasting.
     */
    public function afterSave($insert, $changedAttributes)
    {
        $this->trigger($insert ? self::EVENT_AFTER_INSERT : self::EVENT_AFTER_UPDATE, new AfterSaveEvent([
            'changedAttributes' => $changedAttributes,
        ]));
    }

    /**
     * This method is invoked before deleting a record.
     *
     * The default implementation raises the [[EVENT_BEFORE_DELETE]] event.
     * When overriding this method, make sure you call the parent implementation like the following:
     *
     * ```php
     * public function beforeDelete()
     * {
     *     if (!parent::beforeDelete()) {
     *         return false;
     *     }
     *
     *     // ...custom code here...
     *     return true;
     * }
     * ```
     *
     * @return bool whether the record should be deleted. Defaults to `true`.
     */
    public function beforeDelete()
    {
        $event = new ModelEvent();
        $this->trigger(self::EVENT_BEFORE_DELETE, $event);

        return $event->isValid;
    }

    /**
     * This method is invoked after deleting a record.
     * The default implementation raises the [[EVENT_AFTER_DELETE]] event.
     * You may override this method to do postprocessing after the record is deleted.
     * Make sure you call the parent implementation so that the event is raised properly.
     */
    public function afterDelete()
    {
        $this->trigger(self::EVENT_AFTER_DELETE);
    }

    /**
     * Repopulates this active record with the latest data.
     *
     * If the refresh is successful, an [[EVENT_AFTER_REFRESH]] event will be triggered.
     * This event is available since version 2.0.8.
     *
     * @return bool whether the row still exists in the database. If `true`, the latest data
     * will be populated to this active record. Otherwise, this record will remain unchanged.
     */
    public function refresh()
    {
        /* @var $record BaseActiveRecord */
        $record = static::findOne($this->getPrimaryKey(true));
        return $this->refreshInternal($record);
    }

    /**
     * Repopulates this active record with the latest data from a newly fetched instance.
     * @param BaseActiveRecord $record the record to take attributes from.
     * @return bool whether refresh was successful.
     * @see refresh()
     * @since 2.0.13
     */
    protected function refreshInternal($record)
    {
        if ($record === null) {
            return false;
        }
        foreach ($this->attributes() as $name) {
            $this->_attributes[$name] = isset($record->_attributes[$name]) ? $record->_attributes[$name] : null;
        }
        $this->_oldAttributes = $record->_oldAttributes;
        $this->_related = [];
        $this->_relationsDependencies = [];
        $this->afterRefresh();

        return true;
    }

    /**
     * This method is called when the AR object is refreshed.
     * The default implementation will trigger an [[EVENT_AFTER_REFRESH]] event.
     * When overriding this method, make sure you call the parent implementation to ensure the
     * event is triggered.
     * @since 2.0.8
     */
    public function afterRefresh()
    {
        $this->trigger(self::EVENT_AFTER_REFRESH);
    }

    /**
     * Returns a value indicating whether the given active record is the same as the current one.
     * The comparison is made by comparing the table names and the primary key values of the two active records.
     * If one of the records [[isNewRecord|is new]] they are also considered not equal.
     * @param ActiveRecordInterface $record record to compare to
     * @return bool whether the two active records refer to the same row in the same database table.
     */
    public function equals($record)
    {
        if ($this->getIsNewRecord() || $record->getIsNewRecord()) {
            return false;
        }

        return get_class($this) === get_class($record) && $this->getPrimaryKey() === $record->getPrimaryKey();
    }

    /**
     * Returns the primary key value(s).
     * @param bool $asArray whether to return the primary key value as an array. If `true`,
     * the return value will be an array with column names as keys and column values as values.
     * Note that for composite primary keys, an array will always be returned regardless of this parameter value.
     * @property mixed The primary key value. An array (column name => column value) is returned if
     * the primary key is composite. A string is returned otherwise (null will be returned if
     * the key value is null).
     * @return mixed the primary key value. An array (column name => column value) is returned if the primary key
     * is composite or `$asArray` is `true`. A string is returned otherwise (null will be returned if
     * the key value is null).
     */
    public function getPrimaryKey($asArray = false)
    {
        $keys = static::primaryKey();
        if (!$asArray && count($keys) === 1) {
            return isset($this->_attributes[$keys[0]]) ? $this->_attributes[$keys[0]] : null;
        }

        $values = [];
        foreach ($keys as $name) {
            $values[$name] = isset($this->_attributes[$name]) ? $this->_attributes[$name] : null;
        }

        return $values;
    }

    /**
     * Returns the old primary key value(s).
     * This refers to the primary key value that is populated into the record
     * after executing a find method (e.g. find(), findOne()).
     * The value remains unchanged even if the primary key attribute is manually assigned with a different value.
     * @param bool $asArray whether to return the primary key value as an array. If `true`,
     * the return value will be an array with column name as key and column value as value.
     * If this is `false` (default), a scalar value will be returned for non-composite primary key.
     * @property mixed The old primary key value. An array (column name => column value) is
     * returned if the primary key is composite. A string is returned otherwise (null will be
     * returned if the key value is null).
     * @return mixed the old primary key value. An array (column name => column value) is returned if the primary key
     * is composite or `$asArray` is `true`. A string is returned otherwise (null will be returned if
     * the key value is null).
     * @throws Exception if the AR model does not have a primary key
     */
    public function getOldPrimaryKey($asArray = false)
    {
        $keys = static::primaryKey();
        if (empty($keys)) {
            throw new Exception(get_class($this) . ' does not have a primary key. You should either define a primary key for the corresponding table or override the primaryKey() method.');
        }
        if (!$asArray && count($keys) === 1) {
            return isset($this->_oldAttributes[$keys[0]]) ? $this->_oldAttributes[$keys[0]] : null;
        }

        $values = [];
        foreach ($keys as $name) {
            $values[$name] = isset($this->_oldAttributes[$name]) ? $this->_oldAttributes[$name] : null;
        }

        return $values;
    }

    /**
     * Populates an active record object using a row of data from the database/storage.
     *
     * This is an internal method meant to be called to create active record objects after
     * fetching data from the database. It is mainly used by [[ActiveQuery]] to populate
     * the query results into active records.
     *
     * When calling this method manually you should call [[afterFind()]] on the created
     * record to trigger the [[EVENT_AFTER_FIND|afterFind Event]].
     *
     * @param BaseActiveRecord $record the record to be populated. In most cases this will be an instance
     * created by [[instantiate()]] beforehand.
     * @param array $row attribute values (name => value)
     */
    public static function populateRecord($record, $row)
    {
        $columns = array_flip($record->attributes());
        foreach ($row as $name => $value) {
            if (isset($columns[$name])) {
                $record->_attributes[$name] = $value;
            } elseif ($record->canSetProperty($name)) {
                $record->$name = $value;
            }
        }
        $record->_oldAttributes = $record->_attributes;
        $record->_related = [];
        $record->_relationsDependencies = [];
    }

    /**
     * Creates an active record instance.
     *
     * This method is called together with [[populateRecord()]] by [[ActiveQuery]].
     * It is not meant to be used for creating new records directly.
     *
     * You may override this method if the instance being created
     * depends on the row data to be populated into the record.
     * For example, by creating a record based on the value of a column,
     * you may implement the so-called single-table inheritance mapping.
     * @param array $row row data to be populated into the record.
     * @return static the newly created active record
     */
    public static function instantiate($row)
    {
        return new static();
    }

    /**
     * Returns whether there is an element at the specified offset.
     * This method is required by the interface [[\ArrayAccess]].
     * @param mixed $offset the offset to check on
     * @return bool whether there is an element at the specified offset.
     */
    #[\ReturnTypeWillChange]
    public function offsetExists($offset)
    {
        return $this->__isset($offset);
    }

    /**
     * Returns the relation object with the specified name.
     * A relation is defined by a getter method which returns an [[ActiveQueryInterface]] object.
     * It can be declared in either the Active Record class itself or one of its behaviors.
     * @param string $name the relation name, e.g. `orders` for a relation defined via `getOrders()` method (case-sensitive).
     * @param bool $throwException whether to throw exception if the relation does not exist.
     * @return ActiveQueryInterface|ActiveQuery the relational query object. If the relation does not exist
     * and `$throwException` is `false`, `null` will be returned.
     * @throws InvalidArgumentException if the named relation does not exist.
     */
    public function getRelation($name, $throwException = true)
    {
        $getter = 'get' . $name;
        try {
            // the relation could be defined in a behavior
            $relation = $this->$getter();
        } catch (UnknownMethodException $e) {
            if ($throwException) {
                throw new InvalidArgumentException(get_class($this) . ' has no relation named "' . $name . '".', 0, $e);
            }

            return null;
        }
        if (!$relation instanceof ActiveQueryInterface) {
            if ($throwException) {
                throw new InvalidArgumentException(get_class($this) . ' has no relation named "' . $name . '".');
            }

            return null;
        }

        if (method_exists($this, $getter)) {
            // relation name is case sensitive, trying to validate it when the relation is defined within this class
            $method = new \ReflectionMethod($this, $getter);
            $realName = lcfirst(substr($method->getName(), 3));
            if ($realName !== $name) {
                if ($throwException) {
                    throw new InvalidArgumentException('Relation names are case sensitive. ' . get_class($this) . " has a relation named \"$realName\" instead of \"$name\".");
                }

                return null;
            }
        }

        return $relation;
    }

    /**
     * Establishes the relationship between two models.
     *
     * The relationship is established by setting the foreign key value(s) in one model
     * to be the corresponding primary key value(s) in the other model.
     * The model with the foreign key will be saved into database **without** performing validation
     * and **without** events/behaviors.
     *
     * If the relationship involves a junction table, a new row will be inserted into the
     * junction table which contains the primary key values from both models.
     *
     * Note that this method requires that the primary key value is not null.
     *
     * @param string $name the case sensitive name of the relationship, e.g. `orders` for a relation defined via `getOrders()` method.
     * @param ActiveRecordInterface $model the model to be linked with the current one.
     * @param array $extraColumns additional column values to be saved into the junction table.
     * This parameter is only meaningful for a relationship involving a junction table
     * (i.e., a relation set with [[ActiveRelationTrait::via()]] or [[ActiveQuery::viaTable()]].)
     * @throws InvalidCallException if the method is unable to link two models.
     */
    public function link($name, $model, $extraColumns = [])
    {
        /* @var $relation ActiveQueryInterface|ActiveQuery */
        $relation = $this->getRelation($name);

        if ($relation->via !== null) {
            if ($this->getIsNewRecord() || $model->getIsNewRecord()) {
                throw new InvalidCallException('Unable to link models: the models being linked cannot be newly created.');
            }
            if (is_array($relation->via)) {
                /* @var $viaRelation ActiveQuery */
                list($viaName, $viaRelation) = $relation->via;
                $viaClass = $viaRelation->modelClass;
                // unset $viaName so that it can be reloaded to reflect the change
                unset($this->_related[$viaName]);
            } else {
                $viaRelation = $relation->via;
                $viaTable = reset($relation->via->from);
            }
            $columns = [];
            foreach ($viaRelation->link as $a => $b) {
                $columns[$a] = $this->$b;
            }
            foreach ($relation->link as $a => $b) {
                $columns[$b] = $model->$a;
            }
            foreach ($extraColumns as $k => $v) {
                $columns[$k] = $v;
            }
            if (is_array($relation->via)) {
                /* @var $viaClass ActiveRecordInterface */
                /* @var $record ActiveRecordInterface */
                $record = Yii::createObject($viaClass);
                foreach ($columns as $column => $value) {
                    $record->$column = $value;
                }
                $record->insert(false);
            } else {
                /* @var $viaTable string */
                static::getDb()->createCommand()->insert($viaTable, $columns)->execute();
            }
        } else {
            $p1 = $model->isPrimaryKey(array_keys($relation->link));
            $p2 = static::isPrimaryKey(array_values($relation->link));
            if ($p1 && $p2) {
                if ($this->getIsNewRecord()) {
                    if ($model->getIsNewRecord()) {
                        throw new InvalidCallException('Unable to link models: at most one model can be newly created.');
                    }
                    $this->bindModels(array_flip($relation->link), $this, $model);
                } else {
                    $this->bindModels($relation->link, $model, $this);
                }
            } elseif ($p1) {
                $this->bindModels(array_flip($relation->link), $this, $model);
            } elseif ($p2) {
                $this->bindModels($relation->link, $model, $this);
            } else {
                throw new InvalidCallException('Unable to link models: the link defining the relation does not involve any primary key.');
            }
        }

        // update lazily loaded related objects
        if (!$relation->multiple) {
            $this->_related[$name] = $model;
        } elseif (isset($this->_related[$name])) {
            if ($relation->indexBy !== null) {
                if ($relation->indexBy instanceof \Closure) {
                    $index = call_user_func($relation->indexBy, $model);
                } else {
                    $index = $model->{$relation->indexBy};
                }
                $this->_related[$name][$index] = $model;
            } else {
                $this->_related[$name][] = $model;
            }
        }
    }

    /**
     * Destroys the relationship between two models.
     *
     * The model with the foreign key of the relationship will be deleted if `$delete` is `true`.
     * Otherwise, the foreign key will be set `null` and the model will be saved without validation.
     *
     * @param string $name the case sensitive name of the relationship, e.g. `orders` for a relation defined via `getOrders()` method.
     * @param ActiveRecordInterface $model the model to be unlinked from the current one.
     * You have to make sure that the model is really related with the current model as this method
     * does not check this.
     * @param bool $delete whether to delete the model that contains the foreign key.
     * If `false`, the model's foreign key will be set `null` and saved.
     * If `true`, the model containing the foreign key will be deleted.
     * @throws InvalidCallException if the models cannot be unlinked
     * @throws Exception
     * @throws StaleObjectException
     */
    public function unlink($name, $model, $delete = false)
    {
        /* @var $relation ActiveQueryInterface|ActiveQuery */
        $relation = $this->getRelation($name);

        if ($relation->via !== null) {
            if (is_array($relation->via)) {
                /* @var $viaRelation ActiveQuery */
                list($viaName, $viaRelation) = $relation->via;
                $viaClass = $viaRelation->modelClass;
                unset($this->_related[$viaName]);
            } else {
                $viaRelation = $relation->via;
                $viaTable = reset($relation->via->from);
            }
            $columns = [];
            foreach ($viaRelation->link as $a => $b) {
                $columns[$a] = $this->$b;
            }
            foreach ($relation->link as $a => $b) {
                $columns[$b] = $model->$a;
            }
            $nulls = [];
            foreach (array_keys($columns) as $a) {
                $nulls[$a] = null;
            }
            if (property_exists($viaRelation, 'on') && $viaRelation->on !== null) {
                $columns = ['and', $columns, $viaRelation->on];
            }
            if (is_array($relation->via)) {
                /* @var $viaClass ActiveRecordInterface */
                if ($delete) {
                    $viaClass::deleteAll($columns);
                } else {
                    $viaClass::updateAll($nulls, $columns);
                }
            } else {
                /* @var $viaTable string */
                /* @var $command Command */
                $command = static::getDb()->createCommand();
                if ($delete) {
                    $command->delete($viaTable, $columns)->execute();
                } else {
                    $command->update($viaTable, $nulls, $columns)->execute();
                }
            }
        } else {
            $p1 = $model->isPrimaryKey(array_keys($relation->link));
            $p2 = static::isPrimaryKey(array_values($relation->link));
            if ($p2) {
                if ($delete) {
                    $model->delete();
                } else {
                    foreach ($relation->link as $a => $b) {
                        $model->$a = null;
                    }
                    $model->save(false);
                }
            } elseif ($p1) {
                foreach ($relation->link as $a => $b) {
                    if (is_array($this->$b)) { // relation via array valued attribute
                        if (($key = array_search($model->$a, $this->$b, false)) !== false) {
                            $values = $this->$b;
                            unset($values[$key]);
                            $this->$b = array_values($values);
                        }
                    } else {
                        $this->$b = null;
                    }
                }
                $delete ? $this->delete() : $this->save(false);
            } else {
                throw new InvalidCallException('Unable to unlink models: the link does not involve any primary key.');
            }
        }

        if (!$relation->multiple) {
            unset($this->_related[$name]);
        } elseif (isset($this->_related[$name])) {
            /* @var $b ActiveRecordInterface */
            foreach ($this->_related[$name] as $a => $b) {
                if ($model->getPrimaryKey() === $b->getPrimaryKey()) {
                    unset($this->_related[$name][$a]);
                }
            }
        }
    }

    /**
     * Destroys the relationship in current model.
     *
     * The model with the foreign key of the relationship will be deleted if `$delete` is `true`.
     * Otherwise, the foreign key will be set `null` and the model will be saved without validation.
     *
     * Note that to destroy the relationship without removing records make sure your keys can be set to null
     *
     * @param string $name the case sensitive name of the relationship, e.g. `orders` for a relation defined via `getOrders()` method.
     * @param bool $delete whether to delete the model that contains the foreign key.
     *
     * Note that the deletion will be performed using [[deleteAll()]], which will not trigger any events on the related models.
     * If you need [[EVENT_BEFORE_DELETE]] or [[EVENT_AFTER_DELETE]] to be triggered, you need to [[find()|find]] the models first
     * and then call [[delete()]] on each of them.
     */
    public function unlinkAll($name, $delete = false)
    {
        /* @var $relation ActiveQueryInterface|ActiveQuery */
        $relation = $this->getRelation($name);

        if ($relation->via !== null) {
            if (is_array($relation->via)) {
                /* @var $viaRelation ActiveQuery */
                list($viaName, $viaRelation) = $relation->via;
                $viaClass = $viaRelation->modelClass;
                unset($this->_related[$viaName]);
            } else {
                $viaRelation = $relation->via;
                $viaTable = reset($relation->via->from);
            }
            $condition = [];
            $nulls = [];
            foreach ($viaRelation->link as $a => $b) {
                $nulls[$a] = null;
                $condition[$a] = $this->$b;
            }
            if (!empty($viaRelation->where)) {
                $condition = ['and', $condition, $viaRelation->where];
            }
            if (property_exists($viaRelation, 'on') && !empty($viaRelation->on)) {
                $condition = ['and', $condition, $viaRelation->on];
            }
            if (is_array($relation->via)) {
                /* @var $viaClass ActiveRecordInterface */
                if ($delete) {
                    $viaClass::deleteAll($condition);
                } else {
                    $viaClass::updateAll($nulls, $condition);
                }
            } else {
                /* @var $viaTable string */
                /* @var $command Command */
                $command = static::getDb()->createCommand();
                if ($delete) {
                    $command->delete($viaTable, $condition)->execute();
                } else {
                    $command->update($viaTable, $nulls, $condition)->execute();
                }
            }
        } else {
            /* @var $relatedModel ActiveRecordInterface */
            $relatedModel = $relation->modelClass;
            if (!$delete && count($relation->link) === 1 && is_array($this->{$b = reset($relation->link)})) {
                // relation via array valued attribute
                $this->$b = [];
                $this->save(false);
            } else {
                $nulls = [];
                $condition = [];
                foreach ($relation->link as $a => $b) {
                    $nulls[$a] = null;
                    $condition[$a] = $this->$b;
                }
                if (!empty($relation->where)) {
                    $condition = ['and', $condition, $relation->where];
                }
                if (property_exists($relation, 'on') && !empty($relation->on)) {
                    $condition = ['and', $condition, $relation->on];
                }
                if ($delete) {
                    $relatedModel::deleteAll($condition);
                } else {
                    $relatedModel::updateAll($nulls, $condition);
                }
            }
        }

        unset($this->_related[$name]);
    }

    /**
     * @param array $link
     * @param ActiveRecordInterface $foreignModel
     * @param ActiveRecordInterface $primaryModel
     * @throws InvalidCallException
     */
    private function bindModels($link, $foreignModel, $primaryModel)
    {
        foreach ($link as $fk => $pk) {
            $value = $primaryModel->$pk;
            if ($value === null) {
                throw new InvalidCallException('Unable to link models: the primary key of ' . get_class($primaryModel) . ' is null.');
            }
            if (is_array($foreignModel->$fk)) { // relation via array valued attribute
                $foreignModel->{$fk}[] = $value;
            } else {
                $foreignModel->{$fk} = $value;
            }
        }
        $foreignModel->save(false);
    }

    /**
     * Returns a value indicating whether the given set of attributes represents the primary key for this model.
     * @param array $keys the set of attributes to check
     * @return bool whether the given set of attributes represents the primary key for this model
     */
    public static function isPrimaryKey($keys)
    {
        $pks = static::primaryKey();
        if (count($keys) === count($pks)) {
            return count(array_intersect($keys, $pks)) === count($pks);
        }

        return false;
    }

    /**
     * Returns the text label for the specified attribute.
     * If the attribute looks like `relatedModel.attribute`, then the attribute will be received from the related model.
     * @param string $attribute the attribute name
     * @return string the attribute label
     * @see generateAttributeLabel()
     * @see attributeLabels()
     */
    public function getAttributeLabel($attribute)
    {
        $labels = $this->attributeLabels();
        if (isset($labels[$attribute])) {
            return $labels[$attribute];
        } elseif (strpos($attribute, '.')) {
            $attributeParts = explode('.', $attribute);
            $neededAttribute = array_pop($attributeParts);

            $relatedModel = $this;
            foreach ($attributeParts as $relationName) {
                if ($relatedModel->isRelationPopulated($relationName) && $relatedModel->$relationName instanceof self) {
                    $relatedModel = $relatedModel->$relationName;
                } else {
                    try {
                        $relation = $relatedModel->getRelation($relationName);
                    } catch (InvalidParamException $e) {
                        return $this->generateAttributeLabel($attribute);
                    }
                    /* @var $modelClass ActiveRecordInterface */
                    $modelClass = $relation->modelClass;
                    $relatedModel = $modelClass::instance();
                }
            }

            $labels = $relatedModel->attributeLabels();
            if (isset($labels[$neededAttribute])) {
                return $labels[$neededAttribute];
            }
        }

        return $this->generateAttributeLabel($attribute);
    }

    /**
     * Returns the text hint for the specified attribute.
     * If the attribute looks like `relatedModel.attribute`, then the attribute will be received from the related model.
     * @param string $attribute the attribute name
     * @return string the attribute hint
     * @see attributeHints()
     * @since 2.0.4
     */
    public function getAttributeHint($attribute)
    {
        $hints = $this->attributeHints();
        if (isset($hints[$attribute])) {
            return $hints[$attribute];
        } elseif (strpos($attribute, '.')) {
            $attributeParts = explode('.', $attribute);
            $neededAttribute = array_pop($attributeParts);

            $relatedModel = $this;
            foreach ($attributeParts as $relationName) {
                if ($relatedModel->isRelationPopulated($relationName) && $relatedModel->$relationName instanceof self) {
                    $relatedModel = $relatedModel->$relationName;
                } else {
                    try {
                        $relation = $relatedModel->getRelation($relationName);
                    } catch (InvalidParamException $e) {
                        return '';
                    }
                    /* @var $modelClass ActiveRecordInterface */
                    $modelClass = $relation->modelClass;
                    $relatedModel = $modelClass::instance();
                }
            }

            $hints = $relatedModel->attributeHints();
            if (isset($hints[$neededAttribute])) {
                return $hints[$neededAttribute];
            }
        }

        return '';
    }

    /**
     * {@inheritdoc}
     *
     * The default implementation returns the names of the columns whose values have been populated into this record.
     */
    public function fields()
    {
        $fields = array_keys($this->_attributes);

        return array_combine($fields, $fields);
    }

    /**
     * {@inheritdoc}
     *
     * The default implementation returns the names of the relations that have been populated into this record.
     */
    public function extraFields()
    {
        $fields = array_keys($this->getRelatedRecords());

        return array_combine($fields, $fields);
    }

    /**
     * Sets the element value at the specified offset to null.
     * This method is required by the SPL interface [[\ArrayAccess]].
     * It is implicitly called when you use something like `unset($model[$offset])`.
     * @param mixed $offset the offset to unset element
     */
    public function offsetUnset($offset)
    {
        if (property_exists($this, $offset)) {
            $this->$offset = null;
        } else {
            unset($this->$offset);
        }
    }

    /**
     * Resets dependent related models checking if their links contain specific attribute.
     * @param string $attribute The changed attribute name.
     */
    private function resetDependentRelations($attribute)
    {
        foreach ($this->_relationsDependencies[$attribute] as $relation) {
            unset($this->_related[$relation]);
        }
        unset($this->_relationsDependencies[$attribute]);
    }

    /**
     * Sets relation dependencies for a property
     * @param string $name property name
     * @param ActiveQueryInterface $relation relation instance
     * @param string|null $viaRelationName intermediate relation
     */
    private function setRelationDependencies($name, $relation, $viaRelationName = null)
    {
        if (empty($relation->via) && $relation->link) {
            foreach ($relation->link as $attribute) {
                $this->_relationsDependencies[$attribute][$name] = $name;
                if ($viaRelationName !== null) {
                    $this->_relationsDependencies[$attribute][] = $viaRelationName;
                }
            }
        } elseif ($relation->via instanceof ActiveQueryInterface) {
            $this->setRelationDependencies($name, $relation->via);
        } elseif (is_array($relation->via)) {
            list($viaRelationName, $viaQuery) = $relation->via;
            $this->setRelationDependencies($name, $viaQuery, $viaRelationName);
        }
    }
}