XCVII. Object property and method call overloading

Introduktion

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.

Varning

Den h�r utbyggnaden �r EXPERIMENTELL. Dess beteende -- inkluderat namnen p� funktionerna, och allt annat dokumenterat om den h�r utbyggnaden -- kan �ndras i framtida utg�var av PHP utan n�got tillk�nnagivande. Anv�nd den p� egen risk.

Varning

This extension is not a part of PHP 5. PHP 5 supports __get(), __set() and __call() natively. See the Overloading in PHP 5 page for more information.

Krav

Inga externa bibliotek beh�vs f�r att bygga det till�gg.

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.

Windows-versionen av PHP har inbyggt st�d f�r det h�r till�gget. Du beh�ver inte ladda n�gra ytterligare till�gg f�r att anv�nda dessa funktioner.

Not: Builtin support for overload is available with PHP 4.3.0.

Konfiguration under drift

Den h�r utbyggnaden definerar inte n�gra konfigurationsdirektiv i php.ini.

Resurstyper

Den h�r utbyggnaden har inte n�gra resurstyper definerade.

F�rdefinerade konstanter

Den h�r utbyggnaden har inte n�gra konstanter definerade.

Exempel

Some simple examples on using the overload() function:

Exempel 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);

?>

Innehållsförteckning
overload -- Enable property and method call overloading for a class