I'm seriously confused about the concept of the 'Model' in MVC. Most frameworks that exist today put the Model between the Controller and the database, and the Model almost acts like a database abstraction layer. The concept of 'Fat Model Skinny Controller' is lost as the Controller starts doing more and more logic.
In DDD, there is also the concept of a Domain Entity, which has a unique identity to it. As I understand it, a user is a good example of an Entity (unique userid, for instance). The Entity has a life-cycle -- it's values can change throughout the course of the action -- and then it's saved or discarded.
The Entity I describe above is what I thought Model was supposed to be in MVC? How off-base am I?
To clutter things more, you throw in other patterns, such as the Repository pattern (maybe putting a Service in there). It's pretty clear how the Repository would interact with an Entity -- how does it with a Model?
Controllers can have multiple Models, which makes it seem like a Model is less a "database table" than it is a unique Entity.
So, in very rough terms, which is better?
No "Model" really ...
class MyController {
public function index() {
$repo = new PostRepository();
$posts = $repo->findAllByDateRange('within 30 days');
foreach($posts as $post) {
echo $post->Author;
}
}
}
Or this, which has a Model as the DAO?
class MyController {
public function index() {
$model = new PostModel();
// maybe this returns a PostRepository?
$posts = $model->findAllByDateRange('within 30 days');
while($posts->getNext()) {
echo $posts->Post->Author;
}
}
}
Both those examples didn't even do what I was describing above. I'm clearly lost. Any input?
