Re: Closure and $this

On Wed, Jan 12, 2011 at 10:57 PM, Larry Garfield <larry@garfieldtech.com>wrote: > I believe this is the relevant RFC: > > http://wiki.php.net/rfc/closures/object-extension > That was a good bedtime read last night, Larry. I prefer method A which is nearly identical to Java's inner classes where $this would remain tied to whatever it held when the closure was created and gain the object's scope. I do like the idea of being able to explicitly bind the closure to a new object as well. That's all well and good come PHP 5.4 or 6.0, but for now you are limited to holding a reference to $this without gaining its scope, i.e. you can only access public members. Also, you must assign $this to a new variable because you cannot pass $this in the use() clause. $that = $this; $closure = function(...) use ($that) { ... $that->property ... $that->method() ... } If you need access to a protected or private variable inside the closure, you can pass a reference to it inside use(). Once again you need to first assign the reference to a new variable and then pass that in to the closure. Important: you must use the & operator in the use() clause as well as when creating the reference. class ClosureFactory { private $count = 0; public function create() { $ref = &$this->count; return function() use (&$ref) { return ++$ref; }; } } $factory = new ClosureFactory(); $closure = $factory->create(); for ($i = 0; $i < 5; $i++) { echo $closure(); } Yields 12345 David