adrianwell adrianwell - 4 months ago 34
PHP Question

Extend Wordpress Plugin Class

I’m quite new to OOP, learned the basic idea and logic and now want to extend a wordpress plugin which is not intended for extending it (as far as I can tell):

class Main_Plugin {
function __construct() {
add_action('admin_notice', array($this, 'somefunction');
enter code here
new Main_plugin

So far so good. Now the code of my custom plugin:

class Custom_Plugin extends Main_Plugin {
new Custom_Plugin

From my understanding the object of the “main” plugin is initialized as well as my “child” plugin which means that the

Is there any way to create the “child” plugin correctly so that the “main” plugin is running and my custom plugin just adds some additional functionalities?


You don't really need to extends the Main_Plugin class, if you use class_exists to check if the main plugin class exists.

      new Custom_Plugin;

You can split your main class, one for what you need on every load, one to extend.


There is other way to trigger some custom datas in other class

In the Main_Plugin, you can define your own action/filter or use an existing one:

 $notice_message = apply_filters('custom_notice', $screen, $notice_class, $notice_message);// you need to define parameters before

In any custom plugin you'll be able to hook $notice_message easily:

public function __construct(){
    add_filter('custom_notice', array($this, 'get_notice'), 10, 3); 
public function get_notice($screen, $notice_class, $notice_message){
    $notice_message = __('New notice', 'txt-domain');
    return $notice_message;