Changing the class of an object at runtime
I am working with CMS, Joomla and there is a main class that displays a set of parameters in a JParameter form. It basically has a feature render()
that outputs some HTML that doesn't match the rest of my site.
For maintainability issues and because I have no idea where else this is used, I don't want to change the main code. What would be ideal would be the ability to define a new class that extends JParameter and then move my $ params object into this new subclass.
// existing code --------------------
class JParameter {
function render() {
// return HTML with tables
}
// of course, there a lot more functions here
}
// my magical class -----------------
class MyParameter extends JParameter {
function render() {
// return HTML which doesn't suck
}
}
// my code --------------------------
$this->params->render(); // returns tables
$this->params = (MyParameter) $this->params; // miracle occurs here?
$this->params->render(); // returns nice html
source to share
Always PECL Classkit , but I get the feeling you really don't want to do this. Assuming you are calling directly $this->params->render()
, you might just want to create a function / object that does alternate render ( MyParamRenderer::render($this->params)
), and avoid doing OO gymnastics not supported by the language.
source to share
How about creating a sort decorator that delegates anything apart from JParameter :: render () to an existing object
class MyJParameter {
private $jparm;
function __construct( JParameter $jparm ) {
$this->jparm = $jparm;
}
function render() {
/* your code here */
}
function __get( $var ) {
if( isset( $this->$jparm->$var ) {
return $this->$jparm->$var;
}
return false;
}
function __set( $var, $val ) {
/* similar to __get */
}
function __call( $method, $arguments ) {
if( method_exists( $this->jparm, $method ) {
return call_user_func_array( array( $this->jparm, $method ), $arguments );
}
return false;
}
}
Or is it too smelly?
source to share