I'm new to the OOP paradigm (and AJAX/jQuery), but would like to create a basic site employing MVC architecture, in PHP, with AJAX functionality. I drew up a brief diagram of how I currently 'understand' the architecture.
Presumably when AJAX is used, that acts as the controller to interact with the model directly to retrieve whatever functionality is needed? The filenames I added are just to give you an idea of what I 'think' should be included. e.g. index.php would be a html/css template with includes to modules in the relevant places (whatever they may be) - news.php, navigation.php, etc. database.php/pager.php might house the classes and extended classes that I create for pagination, or connecting/querying the database I'm struggling to see what the controller component could be - it'd surely end up being a 'second back-end view' - calling the classes from the model to be sent to the view?
I've probably portayed my confusion well here - what should go in the view, controller and model... is AJAX functionality technically another controller? Any diagram similar to my one above would be extremely helpful.
There's one way to see this.
From this you should be able to come to your own conclusions.
You can use PHP's best MVC architecture called "YII".Get more info from here http://www.yiiframework.com/
OK so AJAX is a transport method and not a piece of application like a model or controller.
Your client will communicate through AJAX with one or more Controllers.
These Controllers use or invoke Models to handle different kind of tasks.
Then either the controller or the model responds to the request either with a message in a transport-friendly format (JSON, YAML, XML) or with a View (piece of HTML).
The controller handles requests, that means it receives the initial client-input. Depending on the situation this input has to be formatted, normalized, mutated or transformed somehow before being used in your application.
Then a controller uses or invokes a model; this means that it either deals with business logic itself (old style) and makes use of the model to access datasources or it hands the main workflow of your application completely over to the model (new style).
A model in first instance abstracts a persistent storage entity (like a database). In contemporary application design it also does the main business logic of your application.