spl_autoload_register
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
spl_autoload_register — Register given function as __autoload() implementation
Description
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
-
callback -
The autoload function being registered. If
null, then the default implementation of spl_autoload() will be registered.callback(string$class_name): void -
throw -
This parameter specifies whether spl_autoload_register() should throw exceptions when the
callbackcannot be registered. -
prepend -
If true, spl_autoload_register() will prepend the autoloader on the autoload queue instead of appending it.
Return Values
Returns true on success or false on failure.
Changelog
| Version | Description |
|---|---|
| 8.0.0 |
callback is now nullable.
|
Examples
Example #1 spl_autoload_register() as a replacement for an __autoload() function
<?php
// function __autoload($class) {
// include 'classes/' . $class . '.class.php';
// }
function my_autoloader($class) {
include 'classes/' . $class . '.class.php';
}
spl_autoload_register('my_autoloader');
// Or, using an anonymous function
spl_autoload_register(function ($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');
new InexistentClass;
?>
The above example will output something similar to:
[[Foobar\InexistentClass]] Fatal error: Class 'Foobar\InexistentClass' not found in ...
