spl_autoload_register

(PHP 5 >= 5.1.0, PHP 7)

spl_autoload_register — Register given function as __autoload() implementation

Description

spl_autoload_register ([ callable $autoload_function [, bool $throw = true [, bool $prepend = false ]]] ) : bool

Register a function with the spl provided __autoload queue. If the queue is not yet activated it will be activated.

If your code has an existing __autoload() function then this function must be explicitly registered on the __autoload queue. This is because spl_autoload_register() will effectively replace the engine cache for the __autoload() function by either spl_autoload() or spl_autoload_call().

If there must be multiple autoload functions, spl_autoload_register() allows for this. It effectively creates a queue of autoload functions, and runs through each of them in the order they are defined. By contrast, __autoload() may only be defined once.

Parameters

autoload_function

The autoload function being registered. If no parameter is provided, then the default implementation of spl_autoload() will be registered.

throw

This parameter specifies whether spl_autoload_register() should throw exceptions when the autoload_function cannot be registered.

prepend

If true, spl_autoload_register() will prepend the autoloader on the autoload queue instead of appending it.

Return Values

Returns true on success or false on failure.

Examples

Example #1 spl_autoload_register() as a replacement for an __autoload() function

<?php

// function __autoload($class) {
//     include 'classes/' . $class . '.class.php';
// }

function my_autoloader($class) {
    include 'classes/' . $class . '.class.php';
}

spl_autoload_register('my_autoloader');

// Or, using an anonymous function as of PHP 5.3.0
spl_autoload_register(function ($class) {
    include 'classes/' . $class . '.class.php';
});

?>

Example #2 spl_autoload_register() example where the class is not loaded

<?php

namespace Foobar;

class Foo {
    static public function test($name) {
        print '[['. $name .']]';
    }
}

spl_autoload_register(__NAMESPACE__ .'\Foo::test'); // As of PHP 5.3.0

new InexistentClass;

?>

The above example will output something similar to:

[[Foobar\InexistentClass]]
Fatal error: Class 'Foobar\InexistentClass' not found in ...

See Also

© 1997–2020 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.spl-autoload-register.php