I’m trying to use the MVC design pattern for my project but I’m sort of unsure about how to decouple my program into the classes. The first part of my program is a Login screen which requires the user to enter a their username and password and a start button which checks the details, and there is a button to go to a page where you can add a new user. So I was thinking for my MVC design:
loginpanelView : Just the GUI with the text boxes, labels, buttons etc
loginpanelController:
– implement the actionlistener for the start button here and have a reference to the method checkLogin
– implement actionlistener for add user button here and have reference to a method which switches the panels
loginModel:
– defines the actual method which checks the login
switchpanelModel:
– defines a method which creates a cardlayout system and switches the panels
My understanding is that the controller just makes very general references to what needs to be done i.e. sort of what the user wants to happen, then the model defines the exact method of how to handle this? Would someone mind verifying/ correcting my understanding please? I’ve read a lot about this design pattern but unfortunately I still don’t feel like I have a clear understanding of it. Any help would be much appreciated!
p.s. Sorry! I forgot to include that I’m programming in Java
It sometimes helps to think of MVC in terms of dependencies.
The model repesents what your application does. It has no dependencies on anything. It is what makes your application unique.
The view displays information to the user. This information comes from the model. Therefore, the view has a dependency on the model.
The controller’s function is to accept input from the user, dispatch that request to the appropriate model functionality, and (normally) accept the return value and supply it for a view to render. Thus, the controller is usually very tightly coupled to the view(s) that it serves. It also has dependencies on the model.
In this case, the model is your authentication scheme. (In reality, this is not all that much of a model but an entry point in your application, your overall model is something like “process payments”, “generate report”, “request to create widget”, etc.)
You have two views, one to enter authentication information and a second for when an authentication succeeds. The first really does not have any model information, it is solely to collect input (however its design will be based on whatever the authentication model needs, so there is still a dependency here). The second will undoubtedly display a list of available features your application offers or display a landing page etc.
It is the controller’s responsibility to mediate these interactions. Therefore, information sent from the first view is received by the controller, dispatched to the authentication model, authentication succeeds or fails, and then the controller chooses the appropriate view to render based on the result.