MVC in PHP - How does the controller know the view? - php

Question

I'm new to MVC in PHP and I was just wondering what the best way to do this is?
At the moment I've got a simple setup like this:
Model
User.php
Controller
controller.php
View
login.php
register.php
my_account.php
The model has all the database functionality for logging in and registering, and the view files have the relevant working forms.
My main question is, what is the best way to have the controller call pages? Currently, it looks something like:
public function show_page()
{
if ($_GET['p'] == "login")
{
include('View/login.php');
if (isset($_POST['username']))
{
$this->user->login($_POST['username'], $_['pass']
}
}
if ($_GET['p'] == "register") { include('View/register.php'); }
if ($_GET['p'] == "my_account") { include('View/my_account.php'); }
}
This doesn't seem logical, am I doing it wrong?

Answer 1

I think that the best way is to use some kind of routing system so you have a map somewhere with the possible url pattern / page to show combinations and after deciding which controller to call you can load the appropriate view in your controller.
What you presented here seems somewhat blurred to me. I think that you should check out implementations out there like Pure mvc or symfony so you can get a grip on the concept quickly. I believe that you (or anyone else for that matter) shouldn't reinvent the wheel but study, understand and improve what you can get.
If you are going to create your own MVC framework then you should check out the basic MVC concepts and plan your software before trying to write it.

Answer 2

Most PHP based MVC frameworks that I've used utilize a front controller. The .htaccess file directs all traffic to a single (usually index.php) file (usually) in the root of the project.
This file is responsible for determining which application controller to load. That controller is then responsible for any and all application level logic.
in a framework I wrote, in my front controller I do this
$page = tgsf_parse_url();
require resolve_controller( $page );
The tgsf_parse_url function in the above code parses $_SERVER['REDIRECT_URL'] to determine what variables are being passed.
the resolve_controller in the above code handles plugin hooks and 404 conditions, but the bottom line is that it always returns a path to send to include/require so that variable scoping doesn't become an issue (including in a function limits variable scope)
Any variables that are set in the controller are automatically available in a view when you include a view like this:
// this is an application level controller file
$name = 'Mr. Example';
include view( 'example' );
Then in the view file:
<h2><? echo $name; ?></h2>

Answer 3

What you have is not dynamic at all.
This is how I do it in my MVC:
private function loadView(){
//Bring the variables to the global scope
extract($this->getAll()); //load all variables into local scope
if(Config::get('view')){
$template_file = 'view/' . Config::get('view') . '/' . Config::get('method') . '.stp';
if(is_file($template_file)){
include $template_file;
}
else {
include 'view/missingview.stp'; //no such view error
}
}
else {
Config::set('template', 'blank');
include 'view/missingfunction.stp'; //no such function error
}
}
Have something set the view somewhere in the code.
This is how I set the view in the controller:
public function __construct(SessionManager $SESSION) {
$this->pageOn = Config::get('page');
$this->session = $SESSION;
$model_name = $this->name;
if(class_exists($model_name) && is_subclass_of($model_name, 'AppModel')){
/**
* #var AppModel $model_name
*/
$this->$model_name = new $model_name();
}
else {
//default model (no database table chosen)
$this->$model_name = new AppModel();
}
/* Get all posts */
$this->posts = $this->$model_name->getPosts();
Config::set('view', strtolower($model_name)); //<<RIGHT HERE!
if(!$this->session->get(strtolower($model_name))){
$this->session->set(strtolower($model_name), array());
}
}