note 97906 added to functions.anonymous

Here is an example of one way to define, then use the variable ( $this ) in Closure functions. The code below explores all uses, and shows restrictions. The most useful tool in this snippet is the requesting_class() function that will tell you which class is responsible for executing the current Closure(). Overview: ----------------------- Successfully find calling object reference. Successfully call $this(__invoke); Successfully reference $$this->name; Successfully call call_user_func(array($this, 'method')) Failure: reference anything through $this-> Failure: $this->name = ''; Failure: $this->delfect(); <?php function requesting_class() { foreach(debug_backtrace(true) as $stack){ if(isset($stack['object'])){ return $stack['object']; } } } class Person { public $name = ''; public $head = true; public $feet = true; public $deflected = false; function __invoke($p){ return $this->$p; } function __toString(){ return 'this'; } // test for reference function __construct($name){ $this->name = $name; } function deflect(){ $this->deflected = true; } public function shoot() { // If customAttack is defined, use that as the shoot resut. Otherwise shoot feet if(is_callable($this->customAttack)){ return call_user_func($this->customAttack); } $this->feet = false; } } $p = new Person('Bob'); $p->customAttack = function(){ echo $this; // Notice: Undefined variable: this #$this = new Class() // FATAL ERROR // Trick to assign the variable '$this' extract(array('this' => requesting_class())); // Determine what class is responsible for making the call to Closure var_dump( $this ); // Passive reference works var_dump( $$this ); // Added to class: function __toString(){ return 'this'; } $name = $this('name'); // Success echo $name; // Outputs: Bob echo '<br />'; echo $$this->name; call_user_func_array(array($this, 'deflect'), array()); // SUCCESSFULLY CALLED #$this->head = 0; //** FATAL ERROR: Using $this when not in object context $$this->head = 0; // Successfully sets value }; print_r($p); $p->shoot(); print_r($p); die(); ?> ---- Server IP: 69.147.83.197 Probable Submitter: 75.129.163.26 ---- Manual Page -- http://www.php.net/manual/en/functions.anonymous.php Edit -- https://master.php.net/note/edit/97906 Del: integrated -- https://master.php.net/note/delete/97906/integrated Del: useless -- https://master.php.net/note/delete/97906/useless Del: bad code -- https://master.php.net/note/delete/97906/bad+code Del: spam -- https://master.php.net/note/delete/97906/spam Del: non-english -- https://master.php.net/note/delete/97906/non-english Del: in docs -- https://master.php.net/note/delete/97906/in+docs Del: other reasons-- https://master.php.net/note/delete/97906 Reject -- https://master.php.net/note/reject/97906 Search -- https://master.php.net/manage/user-notes.php