Calling a PHP constructor from its own method
class, constructor, extends, methods, php
Solution
You can use
$clsName = get_class($this);
return new $clsName();
But niko's solution also works, useful for a singleton pattern http://php.net/manual/en/language.oop5.static.php
Starting with php 5.3 you can use new features of the `static` keyword.
<?php
abstract class Singleton {
protected static $_instance = NULL;
/**
* Prevent direct object creation
*/
final private function __construct() { }
/**
* Prevent object cloning
*/
final private function __clone() { }
/**
* Returns new or existing Singleton instance
* @return Singleton
*/
final public static function getInstance(){
if( static::$_instance == null){
static::$_instance = new static();
}
return static::$_instance;
}
}
?>
Problem
I've been looking for a way to call a class's constructor that is analogous to "parent::_construct" but for the class itself (something like "self::_construct", though that doesn't work). Why do this? Consider the following (which doesn't work, btw)... ``` class A { var $name; function __construct($name) { $this->name = $name; } function getClone($name) { $newObj = self::__construct($name); return $newObj; } } class B extends A { } ``` In the real implementation there are other properties that will differentiate class B from class A, but both should have the "getClone" method. If called on an object of class A it should yield another object of class A, and if called on class B it should yield another object of class B. Of course I could do this by just overriding "getClone" in class B and hard-coding the class name into the method (i.e., $newObj = new B($name)), but it would be much nicer to just code the method once, telling it to instantiate an object of its own class, whatever that class may be. Will PHP let me do this?