The Popular MVC Design Pattern

If you need reason(s) why the desin pattern are needed in software programming, you can read mw previous post.

Honestly, at the first time I learnt this design pattern, I find it was a bit confusing. Moreover, I find it useless to separate model with the controller, even I can immediaetly find the importance to separate the view an controller. However after try to create a php project using codeigniter framework, I find the requirement are somewhat important.

Before talking further about MVC, let me tell you the basis of MVC. The view, to be simple are the user interface. It is related to everything what user sees, what user input, what user choose and logics of the UI to communicate with controller (in this case, form tag and ajax call are considered a view.

Controller on the contrary, receiving input from view, processing it with logics (if else, loop, mathematical logics, etc), getting the data from model, sending the data to model, and even choose what view will be displayed after all the process done.

Model is the object that you use in controller. Model which data will be displayed in view, which hold the logic to modify the data in storage (can be database, xml, pure text files, encoded file, etc), getting the data from storage, and hold the structure of data.

From that explanation, we can see that it is obvious to separate view with controller, in order to separate business logic with UI logic. But why is it needed for model to be separated with the controller, instead just handle the model (get and modify the data) in controller? We can get the explanation in this post.