Manuel PHP
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# LXXIII. Object property and method call overloading

Avertissement
Ce module est EXPERIMENTAL. Cela signifie que le comportement de ces fonctions, leurs noms et concrètement, TOUT ce qui est documenté ici peut changer dans un futur proche, SANS PREAVIS! Soyez-en conscient, et utiliser ce module à vos risques et périls.

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.

Some simple examples on using the overload() function:

Exemple 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;
    print "\$o->a: $o->a\n"; // print: $o->a:
    print "\$o->b: $o->b\n"; // print: $o->b: 9
    print "\$o->c: $o->c\n"; // print: $o->c: 42
    print "\$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);

    ?>

Avertissement
As this is an experimental extension, not all things work. There is no `__call()` support currently, you can only overload the get and set operations for properties. You cannot invoke the original overloading handlers of the class, and `__set()` only works to one level of property access.

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ob_implicit_flush | Niveau supérieur | overload