How coarse grained should the model be in an MVC framework?

Question

I have been reading a few questions previously asked and I haven't come across one that answers my question in "black and white" for me! So, apologies if this is repetitive. The question is probably similar to asking, "how long is a piece of string" but bear with me!

For a registernation system, I have a user model with functions such as:

• add_user
• delete_user
• activate_user

The above user model deals with one table. The users table in the MySQL database.

You can guess what each function does but is this coarse enough? I mean should my model contain methods that are much broader such as:

• add_record
• delete_record
• update_record

Where I pass in the table and a unique identifier of the record to delete, add or update?

I am using codeigniter, but I am interested in how things should be done in a pure MVC framework.

I apologise if this question is too picky.

Thanks all

Answer 1

I'm not sure what you mean by "coarse".

"should my model contain methods that are much broader such as: add_record, delete_record, update_record"

Absolutely not. Never. That defeats the purpose of having a model.

That kind of "general-purpose" stuff is what a database is for. The point of a model is to adapt the general database to your specific problem.

Your model should be specific to your problem.

"user model with functions such as: add_user, delete_user, activate_user" That's the point. Your model reflects your application, your problem domain, your solution.

Your model should be able to -- in effect -- stand alone. You should be able to wrap your model in a command-line app or a GUI app or a web page.