Where Should Elements Go Using MVC Format Using CodeIgniter

Question

This is my first foray into using an MVC construct (CodeIgniter). I'm hoping someone can tell me where the following elements belong. I have them written; I just want to make sure they're placed properly in their respective locations. This is how my application will run:

1. Call a DB and see if we have a user signed up
2. Route to a signup page
3. Route to the main preferences page for existing users
4. Make DB queries for producing a new user
5. Make update queries when users change their preferences

The service being provided is a cron job cycling every 10 minutes, which I still have written outside of CodeIgniter. Is this something I should/could add to the logic somewhere? It pings Twitter, and does stuff with any new tweets. Let me know if I can clarify any part of this!

Answer 1

1. Model
2. Controller
3. Controller
4. Model
5. Model

Rule of thumb: if it involves the database or the state of the application, it belongs in a model. If it is HTML or presentation logic, it belongs in a view. Controllers handle the rest of the logic, and help link the views and models together.

Answer 2

There are a lot of other things that come up too:

• Where should I sanitise data? As it comes from the model - in the controller or finally before I view? I do it generally in the view if it's something like htmlspecialchars() (though I'm sure others might disagree).

Wikipedia has a very good article.