LXXXII. Object property and method call overloading

Introducere

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.

Avertisment

Această extensie este EXPERIMENTALĂ. Comportamentul acestei extensii, incluzând numele funcţiilor şi orice altceva documentat despre această extensie ar putea fi schimbate fară un anunţ prealabil, intr-o viitoare versiune PHP. V-am avertizat, deci folosiţi această extensie pe riscul dv.

Avertisment

This extension is not a part of PHP 5. PHP 5 supports __get(), __set() and __call() natively. See PHP 5 migration chapter for more information.

Necesităţi

Aceste funcţii sunt disponibile ca părţi ale modulului standard care este întotdeauna disponibil.

Instalare

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.

The windows version of PHP has built in support for this extension. You do not need to load any additional extension in order to use these functions.

Notã: Builtin support for overload is available with PHP 4.3.0.

Configurare la rulare

Această extensie nu defineşte directive de configurare.

Tipuri de resurse

Această extensie nu defineşte tipuri de resurse.

Constante predefinite

Această extensie nu defineşte constante.

Exemple

Some simple examples on using the overload() function:

Exemplu 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);

?>