PHP Reflection

<?php
class person
{
    public $name;
    public $gender;
    
    public function say()
    {
        echo $this->name, " is ", $this->gender, "\r\n";
    }

    public function set($name, $value)
    {
        echo "Setting $name to $value \r\n";
        $this->$name = $value;
    }

    public function get($name)
    {
        if (!isset($this->$name)) {
            echo '未设置';
            $this->$name = "正在为你设置默认值";
        }

        return $this->$name;
    }
}

$student = new person();
$student->name = 'Tom';
$student->gender = 'male';
$student->age = 24;

<?php
$reflect = new ReflectionObject($student);

// 获取对象属性列表
$props = $reflect->getProperties();
foreach ($props as $prop) {
    print$prop->getName() . "\r\n";
}

// 获取对象方法列表
$m = $reflect->getMethods();
foreach ($m as $prop) {
    print $prop->getName() . "\r\n";
}

<?php
// 返回对象属性的关联数组
var_dump(get_object_vars($student));

// 类属性
var_dump(get_class_vars(get_class($student)));

// 返回由类的方法名组成的数组
var_dump(get_class_methods(get_class($student)));

<?php
// 获取对象属性列表所属的类
echo get_class($student);

<?php
// 反射获取类的原型
$obj = new ReflectionClass('person');

$className = $obj->getName();

$Methods = $Properties = array();

foreach ($obj->getProperties() as $v) {
    $Properties[$v->getName()] = $v;
}

foreach ($obj->getMethods() as $v) {
    $Methods[$v->getName()] = $v;
}

echo "class {$className}\r\n{\r\n";

is_array($Properties) && ksort($Properties);

foreach ($Properties as $k => $v) {
    echo "\t";
    echo $v->isPublic() ? ' public' : '', $v->isPrivate() ? ' private' : '',
        $v->isProtected() ? ' protected' : '',
        $v->isStatic() ? ' static' : '';
    echo "\t{$k}\r\n";
}

echo "\r\n";

if (is_array($Methods)) ksort($Methods);

foreach ($Methods as $k => $v) {
    echo "\tfunction {$k}(){}\r\n";
}

echo "}\r\n";

<?php
class mysql
{
    function connect($db)
    {
        echo "连接到数据库${db[0]}\r\n";
    }
}

class sqlproxy
{
    private $target;

    function __construct($tar)
    {
        $this->target[]  = new $tar();
    }

    function call($name, $args)
    {
        foreach ($this->target as $obj) {
            $r = new ReflectionClass($obj);
            if ($method = $r->getMethod($name)) {
                if ($method->isPublic() && !$method->isAbstract()) {
                    echo "方法前拦截记录LOG\r\n";
                    $method->invoke($obj, $args);
                    echo "方法后拦截\r\n";
                }
            }
        }
    }
}

$obj = new sqlproxy('mysql');
$obj->call('connect');

<?php
/** 
 * Class Point 
 */
class Point
{
    public $x;
    public $y;

    /** 
     * Point constructor. 
     * @param int $x horizontal value of point's coordinate 
     * @param int $y vertical value of point's coordinate 
     */
    public function __construct($x = 0, $y = 0)
    {
        $this->x = $x;
        $this->y = $y;
    }
}

<?php
class Circle
{
    /** 
     * 半径 
     * @var int 
     */
    public $radius; 
    
    /** 
     * @var Point 
     */
    public $center;

    // 圆心点
    const PI = 3.14;

    public function __construct(Point $point, $radius = 1)
    {
        $this->center = $point;
        $this->radius = $radius;
    }

    // 打印圆点的坐标
    public function printCenter()
    {
        printf('center coordinate is (%d, %d)', $this->center->x, $this->center->y);
    }

    // 计算圆形的面积
    public function area()
    {
        return 3.14 * pow($this->radius, 2);
    }
}

<?php
// 构建类的对象 
function make($className) { 
    $reflectionClass = new ReflectionClass($className); 
    $constructor = $reflectionClass->getConstructor();
    $parameters = $constructor->getParameters(); 
    $dependencies = getDependencies($parameters); 
    
    return $reflectionClass->newInstanceArgs($dependencies); 
} 

// 依赖解析
function getDependencies($parameters) { 
    $dependencies = []; 
    foreach ($parameters as $parameter) { 
        $dependency = $parameter->getClass(); 
        if (is_null($dependency)) { 
            if ($parameter->isDefaultValueAvailable()) { 
                $dependencies[] = $parameter->getDefaultValue(); 
            } else { 
                // 不是可选参数的为了简单直接赋值为字符串0
                // 针对构造方法的必须参数这个情况
                // laravel是通过service provider注册closure到IocContainer,
                // 在closure里可以通过 return new Class($param1, $param2) 来返回类的实例
                // 然后在make时回调这个closure即可解析出对象
                $dependencies[] = '0'; 
            } 
        } else { 
            // 递归解析出依赖类的对象
            $dependencies[] = make($parameter->getClass()->name); 
        } 
    } 
    
    return $dependencies; 
}

<?php
$circle = make('Circle'); 
$area = $circle->area(); 

/*
var_dump($circle, $area);
 
object(Circle)#6 (2) {
  ["radius"]=>
  int(1)
  ["center"]=>
  object(Point)#11 (2) {
    ["x"]=>
    int(0)
    ["y"]=>
    int(0)
  }
}

float(3.14)*/