Einführung

The purpose of this extension is to allow overloading of object property access and method calls. Only one function is defined in this extension, overload() which takes the name of the class that should have this functionality enabled. The class named has to define appropriate methods if it wants to have this functionality: __get(), __set() and __call() respectively for getting/setting a property, or calling a method. This way overloading can be selective. Inside these handler functions the overloading is disabled so you can access object properties normally.

Anforderungen

Diese Erweiterung benötigt keine externen Bibliotheken.

Installation

In order to use these functions, you must compile PHP with the --enable-overload option. Starting with PHP 4.3.0 this extension is enabled by default. You can disable overload support with --disable--overload.

Die Windowsversion von PHP enthält diese Erweiterung. Um diese Funktionen zu verwenden, müssen Sie keine zusätzlichen Erweiterungen aktivieren.

Laufzeit Konfiguration

Diese Erweiterung definiert keine Konfigurationseinstellungen in der php.ini.

Resource Typen

Diese Erweiterung definiert keine Resource-Typen.

Vordefinierte Konstanten

Diese Erweiterung definiert keine Konstanten.

Beispiele

Some simple examples on using the overload() function:

Beispiel 1. Overloading a PHP class <?php class OO {     var $a = 111;     var $elem = array('b' => 9, 'c' => 42);     // Callback method for getting a property     function __get($prop_name, &$prop_value)     {         if (isset($this->elem[$prop_name])) {             $prop_value = $this->elem[$prop_name];             return true;         } else {             return false;         }     }     // Callback method for setting a property     function __set($prop_name, $prop_value)     {         $this->elem[$prop_name] = $prop_value;         return true;     } } // Here we overload the OO object overload('OO'); $o = new OO; echo "\$o->a: $o->a\n"; // print: $o->a: 111 echo "\$o->b: $o->b\n"; // print: $o->b: 9 echo "\$o->c: $o->c\n"; // print: $o->c: 42 echo "\$o->d: $o->d\n"; // print: $o->d: // add a new item to the $elem array in OO $o->x = 56; // instantiate stdclass (it is built-in in PHP 4) // $val is not overloaded! $val = new stdclass; $val->prop = 555; // Set "a" to be an array with the $val object in it // But __set() will put this in the $elem array $o->a = array($val); var_dump($o->a[0]->prop); ?>