Where to place component code that executes after controller invocation?

Question

For a custom component in Joomla 4 (and 5), is there a way to have some component code that gets executed after the controller execution step, regardless of which controller is triggered?

Why?

In Joomla 1.5, 2 and 3, I had some code in my component that would automatically locate and inject supporting JS and CSS files that matched the view and layout of the page being rendered. This was a single function call into a library function for the purpose, and was invoked as illustrated below, from within the main component PHP file.

Part of the reason for having this particular step after the $controller->execute(...) step is that often the controller will set or adjust the view and layout values eg. if these are not explicitly set in the request.

// Create the controller
$controller = new $controllerName();

// Perform the requested task
$controller->execute( $task );

// Include view and layout specific JS and CSS files if they exist
MyComponentHelper::includeViewFiles();

// Redirect if set by the controller
$controller->redirect();

In Joomla 4, now with DI, it is not obvious how I might achieve the same result. Should I be somehow creating my own custom ComponentDispatcher or ComponentDispatcherFactory class to supply to the DI container? (Probably not.)

Alternatively, if there is a more correct way for me to inject my JS and CSS files (without needing to update every view or every individual controller - I have a lot!), I am also keen to know about that!

Answer 1

If you wanted to follow the same approach then I would say that you should create your own Dispatcher class, which extends the Joomla ComponentDispatcher, but overrides the dispatch() function.

If you define a Dispatcher class with your namespace then the ComponentDispatcherFactory will automatically find it, without needing to change your services/provider.php. It might sound a bit complicated but it's really easy to do. Add a comment if you want more detail about how to go about it.

I would also recommend the web asset manager if you're not already using it, as it makes your life so much easier.