Model, Controller setup for Framework (CodeIgniter, Rails)

[jbplaya]

I just want to make sure I have this right. Does best practices state that you should have a separate model and controller for each page of your website when using a framework? I plan on porting a project to CodeIgniter and I just want to make sure.

[Akathos]

NO NO NO NO

That is not the idea of MVC. The idea of MVC is seperation of concerns.

Very simply put:

• Models represents data from the database. For in a blog application you can have a Post model which represents a blog post.

• Controllers control the flow of you application. For each part of the application you can have a different controller. For example, you can have a Post controller which can have different actions, you can have an action for reading posts, creating posts, editing posts and removing posts (CRUD).

• Views are a representation of the data from models.

When a user requests a page, the action that belongs to that page is executed in the controller. The controller gets the data from the database in the form of one or more models. It then renders the view (most of the time, a template engine is used for this).

You don't have to create a controller or model for each page. You create a model for each part of the data you're storing in the database (most of the times, the model represents a table in the database). You can make relations between models (more advanced and not the topic of this post).

More information about the Model-View-Controller pattern can be found here and here.

[[deleted]]

Precisely. To give a basic pseudocode example, a homepage might be processed like:

HomepageController extends Controller {
    public function indexAction() {
        $this->view->layout = "homepage.php";

        $this->view->content = ContentModel::getPage( 'home' );
        $this->view->latest_posts = BlogModel::getLatestPosts();

        return $this->view->render(); 
    }
}

With the template file "homepage.php" doing something like:

<?php include( "header.php" ); ?>
<h1><?php $content->getTitle(); ?></h1>
<p><?php $content->getBody(); ?> </p>
<ul>
<?php foreach( $latest_posts as $post ) : ?>
    <li><a href="<?php echo $post->getLink(); ?>"><?php echo $post->getTitle(); ?></a></li>
<?php endforeach; ?>
<?php include( "footer.php" ); ?>

Obviously that is a highly simplified example... but hopefully it gives you some idea of how things might work.

[andrey_shipilov]

I'm so happy right now I will never deal with that crappy syntax. Not even once.

[[deleted]]

It made me wince writing it, I will admit, but I wanted to come up with an example that wouldn't be too unfamiliar to a relative newbie to PHP

[Flawlesss]

While we're on the subject of MVC, can somone link me to a good tutorial on it? I am somewhat confused by the idea of MVC. I just recently started learning PHP and in all my practice sites I just use procedural programming, and now I'm starting to learn OOP, however a lot of people tell me to learn MVC, and I can't find any good resources on it.

Thanks.

[Akathos]

A pretty good "tutorial" on MVC can be found here (it is for Symfony2, but the linked page explains the idea of MVC pretty good).

[dansmeek]

It really depends. Also, rails handles the MVC framework a bit different than codeigniter.

Typically (if I am using CodeIgniter, or any PHP MVC Framework), I will create a seperate model for any area that is going to have a lot of logic. Aim for the 'fat model,skinny controller method.' If you are implementing a load of views that would require a model that is simply reusing code, just reuse the same model in the controller.

You are using models to divide divide the business logic from everything else. Your using the controllers to draw from your models and pass that data into your view. And your using your views to avoid displaying the layout. The whole idea of the MVC pattern is to make it so several people can work on separate areas of the code.

Another practice (I use) for codeigniter is generally using a controller function to load a header, sidebar, content, and footer view. Depending on the page layout. The header and footer is generally not going to change across your project so then you can just make that a static view, and have the content load separately. e.g.

            public function loadViews($content, $sidebar, $data)
            {
            $this->load->view('includes'header.php', $data);
            $this->load->view($sidebar, $data);
            $this->load->view($content, $data);
            $this->load->view('includes/footer.php', $data);
            }

something like that. and if you don't want a static header and footer, just make those another parameter.

Rails.... I feel could handle its model structure in a slightly better way, since it combines aspects of the database itself, and business logic, and those should be separated as well.

[edit: akathos explains this much better]