PHP5: Fake Method Overloading

Posted: June 5th, 2009 | Author: Rob Searles | Filed under: PHP, Tutorials | Comments

Been struggling for the past hour or so with method overloading within objects, so I thought I’d write a little not on my blog to hopefully help others and to remind myself.

The premise for this is that I was writing a new database wrapper class to speed up the rather rubbish database module I have been using previously. My plan was to encapsulate all my methods in the wrapper (such as get_table_name() etc) in my class then all others fire off to the ADODB class by PHPlens. My plan was to do this with method overloading, such as:

public function __call($m, $a) {
return $this-&gt;db-&gt;$m($a);
throw new Exception('Tried to call unknown method '.get_class($this-&gt;db).'::'.$m);
}

However, PHP5 doesn’t seem to support that, which is irritating. After some search on the web I find out that PHP5 doesn’t support real overloading.

So after much effort and searching the web and docs I decide to use the call_user_func_array(&obj) technique.

Finished method below:

public function __call($m, $a) {
// check the method being called exists
if (method_exists($this-&gt;db, $m)) {
return call_user_func_array(array(&amp;$this-&gt;db, $m), $a);
}
else {
throw new Exception('Tried to call unknown method '.get_class($this-&gt;db).'::'.$m);
}
}