php实现事件监听与触发实例程序_PHP教程

class Event
{
protected static $listens = array();

public static function listen($event, $callback, $once=false){
if(!is_callable($callback)) return false;
self::$listens[$event][] = array('callback'=>$callback, 'once'=>$once);
return true;
}

public static function one($event, $callback){
return self::listen($event, $callback, true);
}

public static function remove($event, $index=null){
if(is_null($index))
unset(self::$listens[$event]);
else
unset(self::$listens[$event][$index]);
}

public static function trigger(){
if(!func_num_args()) return;
$args = func_get_args();
$event = array_shift($args);
if(!isset(self::$listens[$event])) return false;
foreach((array) self::$listens[$event] as $index=>$listen){
$callback = $listen['callback'];
$listen['once'] && self::remove($event, $index);
call_user_func_array($callback, $args);
}
}
}

// 增加监听walk事件
Event::listen('walk', function(){
echo "I am walking...n";
});
// 增加监听walk一次性事件
Event::listen('walk', function(){
echo "I am listening...n";
}, true);
// 触发walk事件
Event::trigger('walk');
/*
I am walking...
I am listening...
*/
Event::trigger('walk');
/*
I am walking...
*/

Event::one('say', function($name=''){
echo "I am {$name}n";
});

Event::trigger('say', 'deeka'); // 输出 I am deeka
Event::trigger('say', 'deeka'); // not run

class Foo
{
public function bar(){
echo "Foo::bar() is calledn";
}

public function test(){
echo "Foo::foo() is called, agrs:".json_encode(func_get_args())."n";
}
}

$foo = new Foo;

Event::listen('bar', array($foo, 'bar'));
Event::trigger('bar');

Event::listen('test', array($foo, 'test'));
Event::trigger('test', 1, 2, 3);

class Bar
{
public static function foo(){
echo "Bar::foo() is calledn";
}
}

Event::listen('bar1', array('Bar', 'foo'));
Event::trigger('bar1');

Event::listen('bar2', 'Bar::foo');
Event::trigger('bar2');

function bar(){
echo "bar() is calledn";
}

Event::listen('bar3', 'bar');
Event::trigger('bar3');