call_user_method
Something to note,
If the $original class has not yet been defined or loaded, the auto loader will be invoked in order to try and load it.
If the class for which you are trying to create an alias does not exist, or can not be loaded with the auto loader, you will generate a PHP Warning.
class_alias
(PHP 5 >= 5.3.0)
class_alias — Creates an alias for a class
Opis
bool class_alias
([ string
$original
[, string $alias
]] )
Creates an alias named alias
based on the defined class original.
The aliased class is exactly the same as the original class.
Parametry
-
original -
The original class.
-
alias -
The alias name for the class.
Zwracane wartości
Zwraca TRUE w przypadku powodzenia, FALSE w
przypadku błędu.
Przykłady
Przykład #1 class_alias() example
<?php
class foo { }
class_alias('foo', 'bar');
$a = new foo;
$b = new bar;
// the objects are the same
var_dump($a == $b, $a === $b);
var_dump($a instanceof $b);
// the classes are the same
var_dump($a instanceof foo);
var_dump($a instanceof bar);
var_dump($b instanceof foo);
var_dump($b instanceof bar);
?>
Powyższy przykład wyświetli:
bool(true) bool(false) bool(true) bool(true) bool(true) bool(true) bool(true)
Zobacz też:
- get_parent_class() - Pobiera nazwę klasy przodka dla obiektu lub klasy
- is_subclass_of() - Zwraca TRUE jeżeli klasa jest jednym z przodków obiektu
add a note
User Contributed Notes
class_alias
adam at adamhahn dot com
06-Sep-2011 06:13
programmer-comfreek at hotmail dot com
15-Aug-2011 03:38
If you defined the class 'original' in a namespace, you will have to specify the namespace(s), too:
<?php
namespace ns1\ns2\ns3;
class A {}
class_alias('ns1\ns2\ns3\A', 'B');
/* or if you want B to exist in ns1\ns2\ns3 */
class_alias('ns1\ns2\ns3\A', 'ns1\ns2\ns3\B');
?>
nicolas dot grekas+php at gmail dot com
30-Dec-2010 06:09
At first, you might wonder that:
<?php class A {}; class_alias('A', 'B'); ?>
is equivalent to:
<?php class A {}; class B extends A {}; ?>
BUT when derivation creates a new class name - that means, you can then instantiate a new kind of objects - aliasing is just what it says: a synonym, so objects instantiated with the aliased name are of the exact same kind of objects instantiated with the non-aliased name.
See this code for example:
<?php
class A {};
class B1 extends A {};
class_alias('A', 'B2');
$b1 = new B1; echo get_class($b1); // prints B1
$b2 = new B2; echo get_class($b2); // prints A !
?>
nicolas dot grekas+php at gmail dot com
30-Dec-2010 07:41
class_alias also works for interfaces!
<?php
interface foo {}
class_alias('foo', 'bar');
echo interface_exists('bar') ? 'yes!' : 'no'; // prints yes!
?>
paul [dot] kotets [at] gmail [dot] com
02-Sep-2009 09:43
This function will appear in PHP 5.3 (at least I can use it with PHP 5.3, build Aug 7 2009 08:21:14)
For older versions of PHP I wrote the next function:
<?php
if (!function_exists('class_alias')) {
function class_alias($original, $alias) {
eval('abstract class ' . $alias . ' extends ' . $original . ' {}');
}
}
?>
Keyword 'abstract' is used for classes, which defines abstract methods.
This function is used in autoload purposes (when I extend classes), so abstract keyword doesn't broke anything for me.