Dynamic PHP website with MVC - What navigation pattern is this? - php

Question

All,
I am studying some sample code given in my web dev class as an example of MVC (again, for the web). In this code, there's a system to navigate from the index.php page to the various controllers (which then call the Model and View modules), and then back into index.php.
I understand how the MVC works.
What I'm grappling with is the navigation mechanism. I am having difficulties understanding how all the pieces work together.
Could anyone take a look at the code below and tell me if this matches a well known method / pattern to deal with dynamic website navigation? (Maybe the Front Controller?) If it does, then my hope is that I can more easily do some more research on it.
Many thanks!
JDelage
Index.php
<?php
require_once("User.php");
session_start();
if (isset($_GET['action']))
$action= $_GET['action'];
else
$action="";
switch ($action) {
case 'login':
require_once('Login.php');
$command= new LoginControler();
break;
case 'logoff':
require_once('Logoff.php');
$command= new LogoffControler();
break;
// Several other cases
default:
require_once('Unknown.php');
$command= new UnknownControle();
}
$command->execute();
require_once('EntryMenu.php'); // Those are objects that represent both the
// menu label and the links.
$menu= array(
new EntryMenu("Login", "index.php", array("action" => "logon")),
new EntryMenu("Logoff", "index.php", array("action" => "logoff")),
new EntryMenu("Write", "index.php", array("action" => "write")),
new EntryMenu("Read", "index.php", array("action" => "read"))
);
if ($command->redirect) {
header('Location: ' . $command->redirect);
} else if ($command->page) {
include("ui/header.php");
include("ui/menu.php");
echo "<div class='content'>";
include("ui/". $command->page);
echo "</div>";
include("ui/footer.php");
}
?>
Controler.php
<?php
class Controler {
public $page= "problem.php";
function execute() {}
}
?>
LogoffControler.php
<?php
require_once('Controler.php');
class LogoffControler extends Controler {
function execute() {
$this->redirect= "index.php";
unset($_SESSION['user']);
}
}
?>
LoginControler.php
<?php
require_once('LoginModel.php'); // This manages the exchanges with the user db
require_once('Controler.php');
class ConnexionControle extends Controler {
public $page= "LoginForm.php";
function execute() {
// More code to deal with incorrectly filled login forms
$login = new LoginModel();
$login->loginUser($_POST['login'], $_POST['password']);
if ($login->userLogedIn()) {
$_SESSION['user']= $login->user;
$this->redirect= "index.php";
}
// More code to deal with invalid logins
}
}
?>

Answer 1

I am assuming you understand the controller part, and is asking about the switch..case statements. I haven't come across an official name for that yet,but most MVC frameworks for PHP (Kohana, CakePHP, CodeIgniter, Fat Free and etc.) calls that 'routing'. It's mapping of a URL to a controller.
Using a switch..case sets of statement is one of the easier ways. More sophisticated solutions use RegEx to match pre-defined URL patterns to resolve what controller to invoke, and what are its parameters (usually bundled as a 'request')
Other methods include using URL rewriting to come up with pretty urls, such as /articles/month/nov/article-id/3
which in 'ugly url form' is :
action=articles&month=nov&article-id=3

Answer 2

If you would like an easy-to-dissect verion of a MVC system you could try the 1kb PHP MVC which handles everything you are attempting in a much cleaner fashion. Though you might have to break up the code if you really want to read it as it is in compressed form.
With this system you simply place a controller in /classes/controller/ named somthing.php and you can then access it from the URL like http://site.com/something.
Loading Models is also easy and doesn't require any include or require calls.
class Controller_Something
{
public function index()
{
$model = new Model_User();
}
}