Question

Recently I have started working with Codeigniter framework in order to develop RESTFul web service for mobile application.

As I was looking at various tutorials on web sites and on youtube, I found that the concept of a Model is being used differently in PHP application context.

How differently?

Well, as I always thought Model classes should look like,

Cat.php

<?php

class Cat {
   
   // Class variables
   private $colour;
   
   public __construct() {
      $colour = 'Brown';
   }

   // Getters and Setters

   public function getColour() {
      return $this->colour;
   }

   public function setColour($newColour) {
      $this->colour = $newColour;
   }

}

?>

but, while searching for good tutorials over the internet I found that people are just using functions that has access to the database for data and returning it to Controller.

I haven’t seen any one writing normal classes in Model (If you are Java person then, we call it POJO)

---

Now, What I entailed after reading and watching these tutorials that,

In context of PHP application frameworks, The Model classes are connectors to the database which returns the application related data upon query. In language of SQL people we call it,

• CRUD functions

  • Create
  • Read
  • Update
  • Delete

So, correct me if I am wrong.

In web application created by taking base of Codeigniter like framework, where the MVC pattern is used to design an application. The Model classes are the one which will have functions that connects application to the database and returns the data, as well as helps to perform all CRUD operations on application’s database.

Answer 1

Well, if you have used C# or Ruby, there you can find a good way to apply the MVC pattern. In PHP, in my opinion, people sometimes are confused about the terms. The way I use the MVC pattern in PHP is like the following:

CONTROLLER

class UserController { 

    private $repo;

    public function __construct() { 
        $this->repo = new UserRepository(); // The file which communicates with the db. 
    }

    // GET
    // user/register
    public function register() { 
        // Retrieve the temporary sessions here. (Look at create function to understand better)
        include $view_path;
    }

    // POST
    // user/create
    public function create() { 
        $user = new User($_POST['user']); // Obviously, escape and validate $_POST;
        if ($user->validate())
            $this->repo->save($user); // Insert into database

        // Then here I create a temporary session and store both the user and errors.
        // Then I redirect to register
    }

}

MODEL

class User { 

    public $id;
    public $email;

    public function __construct($user = false) {
        if (is_array($user))
            foreach($user as $k => $v) 
                $this->$$k = $v;
    } 

    public function validate() { 
        // Validate your variables here
    }

}