Question

Here’s an example structure of the DB I have:

In the Student view form, I’ve added the form to add a file.

In the Student Controller, when I create or update an entry, I manage the file upload and the creation of the File database entry.

What I want to know is, in the MVC design pattern, what is the right way to do this ? Is it that my Student controller must be aware of the way my File model is done and must know how to add a file?

Or the best way to do this would be that in my Student controller, I call the add or update action of the File controller? But in that way, am I breaking the MVC ?

Thanks!

Answer 1

Ways you are breaking the MVC:

• controller being responsible application logic and maybe even persistence (it should only be changing the sate of model layer and view)
• model is not any single class, it is a layer made up from different classes with different responsibilities (there is no “file model” or “”student model”)

In best case scenario, the controller would have no feedback from data, that it passed on to model layer (preferably through some service, that would be dealing with application logic withing domain model layer).

Instead the view instance, when it starts to assemble the response for the user would check up on model’s state (through services again), to see if there has something changed. In case of an upload, this would be the point where view discovers the result of your upload and, based on data, decides how to respond. Usually in case of file upload the response will contain only a HTTP location header.

_{I am assuming that you are talking about MVC in context of web, based on your profile history. In classical MVC the view would have know about changes in model layer without explicitly checking it, because of the observer pattern which is used there.}

While you most likely will have some “upload controller”, it should not directly interact with domain objects or storage abstractions. Instead it just takes a user’s request, extract data from it and passes it where it needs to go.

_{Keep in mind, that in web applications the “user” is a web browser, not the person that works with it.}