PHP MVC: How to exit from Actions/Controllers early? - php

Question

In a PHP MVC framework, how can I cleanly and elegantly exit from the current controller/action, but continue normal script execution?
For example, let's say my framework normally follows this outline:
Map URL to Controller/Action
Instantiate Controller, call Action (capturing output)
Do stuff
Render View
At end of Action method, continue normal operation
Process output if necessary
Send output to browser
Now, let's say I want to stop "normal" execution somewhere in the "Do Stuff" step to, say, render a different view, or do a header redirect, and I want to stop processing the rest of the body of the Action, but continue onto the "Process output" step
How can I achieve this the best way? My only ideas are:
//in controller
protected function redirect($url) {
header("Location: $url");
exit();
}
but this entirely skips the rest of the framework's execution, and dumps whatever was in the output buffer straight to the user. An alternative:
//in dispatcher
call_user_func_array(array($controller,$action),$params);
afterwards:
...
//in controller
protected function redirect($url) {
header("Location: $url");
goto afterwards;
}
However, this makes me twitch and goes against everything I've learned, especially because the label it's referencing is in another file completely.
So, is there any other way to achieve this?
Note: The redirect example probably should use the exit() way, because we're just redirecting to another page anyway and don't care about output. I'm looking for a general-use solution.

Answer 1

In your Action method, you can collect all of your output in a string rather than printing it out. Print it out only at the end of the method. If you need to redirect or bail out, then you haven't output anything yet and you can either redirect or return from the method.

Answer 2

Perhaps you could write a custom exception to represent a "Stop normal execution in the 'Do Stuff'" step? It's messy... but it would work.

Answer 3

you need to abstract much more things. dont just output inside a action! dont set headers as there can go so much wrong before. have different handlers. response handler. handle respons and act depending what you respond. dont just output inside actions. if you have errors throw exceptions catch them with a exceptionhadler and so on.
basic controller action
public function view(int $user_id): ResponseHandler {
$this->validate($user_id); //throws exception
if (1 == 2) throw new ControllerInvalidArgumentException();
$view = new View('nameof view');
return new ResponseHandler($view);
}
just have a look at existing frameworks they have very good implemntations of design patterns like laravel or symfony. not sure what you try just dont write your own framework. if you want to learn read and learn from others if you understand whyt they do you will know how to do.