ID: 45925
User updated by: david at grudl dot com
Reported By: david at grudl dot com
Status: Wont fix
Bug Type: Feature/Change Request
Operating System: -
PHP Version: 5.3.0alpha1
New Comment:
Thats right (this is mentioned in text). But interface Callable can
exists without any method (so-called "marker interface").
What about two others solutions?
Previous Comments:
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[2008-08-26 20:08:12] [EMAIL PROTECTED]
__invoke takes arbitrary arguments, which means you can't have an
interface that covers it.
------------------------------------------------------------------------
[2008-08-26 16:33:13] david at grudl dot com
Description:
------------
It should be useful to encapsulate PHP pseudotype callback using new
magic method __invoke(). But this type of "callable" objects are not
distinguishable by any interface or class name (compare it with
ArrayAccess or Countable interfaces).
// this is simple callback encapsulation
class Callback
{
private $callback;
public function __construct($callback)
{
$this->callback = $callback;
}
public function __invoke()
{
$args = func_get_args();
return call_user_func_array($this->callback, $args);
}
}
// a Callback object:
$callback = new Callback(array('MyClass', 'anyMethod'));
// a Closure object:
$closure = function() { ... };
The problem: there is nothing common between Callback and Closure
object, what can be used (for example) as type hinting.
First solution using interface:
interface Callable {
function __invoke()
}
class Callback implements Callable { ... }
function event(Callable $obj)
{
$obj($sender, $param);
}
event($callback);
event($closure); // do not work
The class Closure is not Callable implementor thus it do not work.
Problematic is __invoke method's parameters too.
The other way:
class Callback extends Closure { ... } // do not work
function event(Closure $obj)
{
$obj($sender, $param);
}
event($callback);
event($closure);
This is not possible, because Closure is final. Solution is make
Closure non-final.
The third way - create static factory to encapsulate PHP callback as
Closure:
function event(Closure $obj)
{
$obj($sender, $param);
}
$callback = Closure::factory(array('MyClass', 'anyMethod'));
event($callback);
event($closure);
Maybe the most easy way.
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Edit this bug report at http://bugs.php.net/?id=45925&edit=1
