Installing extensions in homemade CMS

Question

I've built my own CMS for learning purposes (and also just for fun), but now I would like to expand it, so that it supports some basic form of extensions (plugins). I would like to work with some kind of observer-pattern where extensions register themselves by the ExtensionManager for certain updates (for example onRenderTitle()). Every extension would consist of one mandatory class ExtensionData that would be executed for every extension in the system. The extensions could register themselves in this class by using a callback (the ExtensionManager would be passed on to every ExtensionData class). But now every extension has to register itself with every page load (because PHP loses state between every page load), causing potential performance problems. Am I doing this completely wrong? Or is this the way to go? I have no experience in writing a CMS that supports extensions (that's what I'm trying to learn). I looked at how Wordpress works with extensions, but I haven't found how it loads them up. JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

Plugins in Wordpress are registered just by being placed in the wp-content/plugins folder, and they have to have the necessary docblocks in its main file. It is also a convention in WP that your plugin's main file has the same name as your plugin plus the .php extension, e.g. plugins/myplugin/myplugin.php. As far as interaction with the core of your CMS goes, you can have your system to fire events and the plugins would then listen for them. WP uses actions and filters for it. Your code for a simple event listener could look following then: action('action_name', function() { // some code to be executed after event is fired }); Your action() function could just update a global array of actions. When you want to fire the event, you just filter through the array of assigned actions. foreach ($actions['action_name'] as $func) { call_user_func($func); }