Sample code sharing of PHP proxy mode

<?php
// 代理模式

function echoLine($msg) {
	echo $msg, &#39;<br/>&#39;;
}

interface Sourceable
{
	function method();
}

// 被代理对象
class Source implements Sourceable
{
	public function method() {
		echoLine(&#39;call method&#39;);
	}
}

// 代理对象
class Proxy implements Sourceable
{
	private $sourceable = null;
	
	// 代理关系在编译时确定
	public function construct() {
		$this->sourceable = new Source();
	}
	
	// 动态设置代理对象
	public function setTarget(Sourceable $s) {
		$this->sourceable = $s;
	}
	
	public function method() {
		echoLine(&#39;before proxy!&#39;);
		$this->sourceable->method();
		echoLine(&#39;after proxy!&#39;);
	}
}

// test code
$proxy = new Proxy();
$proxy->method();

$s = new Source();
$proxy->setTarget($s);
$proxy->method();