php 钩子 事件 区别,事件驱动的架构和钩子在PHP

Good reference material on how to code an event-driven application

class Hooks

{

private $hooks;

public function __construct()

{

$this->hooks = array();

}

public function add($name, $callback) {

// callback parameters must be at least syntactically

// correct when added.

if (!is_callable($callback, true))

{

throw new InvalidArgumentException(sprintf('Invalid callback: %s.', print_r($callback, true)));

}

$this->hooks[$name][] = $callback;

}

public function getCallbacks($name)

{

return isset($this->hooks[$name]) ? $this->hooks[$name] : array();

}

public function fire($name)

{

foreach($this->getCallbacks($name) as $callback)

{

// prevent fatal errors, do your own warning or

// exception here as you need it.

if (!is_callable($callback))

continue;

call_user_func($callback);

}

}

}

$hooks = new Hooks;

$hooks->add('event', function() {echo 'morally disputed.';});

$hooks->add('event', function() {echo 'explicitly called.';});

$hooks->fire('event');

或者实现在事件驱动应用程序中经常使用的模式：Observer Pattern.

Code snippet(s) showing how to put a “hook” in a function in PHP