What would my controller be in these scenarios in a mvc web application?

Question

1) Where does the homepage of your website fit into "controllers"? I've seen some people use a "page" controller to handle static pages like, about, home, contact, etc., but to me this doesn't seem like a good idea. Would creating a distinct controller just for your homepage be a better option? After all, it may need to access multiple models and doesn't really flow well with the whole, one controller per model theory that some people use.

2) If you need a dashboard for multiple types of users, would that be one dashboard controller that would have toggle code dependent upon which user, or would you have say a dashboard action within each controller per user? For example, admin/dashboard, account/dashboard, etc.

3) It seems to me that using the whole simple CRUD example works like a charm when trying to explain controllers, but that once you get past those simple functions, it breaks down and can cause your controllers to get unwieldy. Why do some people choose to create a login controller, when others make a login function in a user controller? One reason I think is that a lot of us come from a page approach background and it's hard to think of controllers as "objects" or "nouns" because pages don't always work that way. Case in point why on earth would you want to create a "pages" controller that would handle pages that really have nothing to do with each other just to have a "container" to fit actions into. Just doesn't seem right to me.

4) Should controllers have more to do with a use case than an "object" that actions can be performed on? For all intensive purposes, you could create a user controller that does every action in your whole app. Or you could create a controller per "area of concern" as some like to say. Or you could create one controller per view if you wanted. There is so much leeway that it makes it tough to figure out a consistent method to use.

Controllers shouldn't be this confusing probably, but for some reason they baffle the hell out of me. Any helpful comments would be greatly appreciated.

Answer 1

1) I use a simple homebrew set of classes for some of my MVC stuff, and it relates controller names to action and view names (it's a Front Controller style, similar to Zend). For a generic web site, let's assume it has a home page, privacy policy, contact page and an about page. I don't really want to make separate controllers for all these things, so I'll stick them inside my IndexController, with function names like actionIndex(), actionPrivacy(), actionContact(), and actionAbout().

To go along with that, inside my Views directory I have a directory of templates associated with each action. By default, any action automatically looks for an associated template, although you can specify one if you wish. So actionPrivacy() would look for a template file at index/privacy.php, actionContact() would look for index/contact.php, etc.

Of course, this relates to the URLs as well. So a url hit to http://www.example.com/index/about would run actionAbout(), which would load the About page template. Since the about page is completely static content, my actionAbout() does absolutely nothing, other than provide a public action for the Front Controller to see and run.

So to answer the core of your question, I do put multiple "pages" into a single controller, and it works fine for my purposes. One model per controller is a theory I don't think I'd try to follow when working with Web MVC, as it seems to fit an application with state much better.

2) For this, I would have multiple controllers. Following the same methods I use above, I would have /admin/dashboard and /account/dashboard as you suggest, although there's no reason they couldn't use the same (or portions of the same) templates.

I suppose if I had a gazillion different kinds of users, I'd make things more generic and only use one controller, and have a mod_rewrite rule to handle the loading. It would probably depend on how functionally complex the dashboard is, and what the account set up is like.

3) I find CRUD functionality difficult to implement directly into any layer of MVC and still have it be clean, flexible and efficient. I like to abstract CRUD functionality out into a service layer that any object may call upon, and have a base object class from which I can extend any objects needing CRUD.

I would suggest utilizing some of the PHP ORM frameworks out there for CRUD. They can do away with a lot of the hassle of getting a nice implementation.

In terms of login controller versus user controller, I suppose it depends on your application domain. With my style of programming, I would tend to think of "logging in" as a simple operation within the domain of a User model, and thusly have a single operation for it inside a user controller. To be more precise, I would have the UserController instantiate a user model and call a login routine on the model. I can't tell you that this is the proper way, because I couldn't say for sure what the proper way is supposed to be. It's a matter of context.

4) You're right about the leeway. You could easily create a controller that handled everything your app/site wanted to do. However, I think you'd agree that this would become a maintenance nightmare. I still get the jibbly-jibblies thinking about my last job at a market research company, where the internal PHP app was done by an overseas team with what I can only assume was little-to-no training. We're talking 10,000 line scripts that handled the whole site. It was impossible to maintain.

So, I'd suggest you break your app/site down into business domain areas, and create controllers based on that. Figure out the core concepts of your app and go from there.

Example

Let's say I had a web site about manatees, because obviously manatees rock. I'd want some normal site pages (about, contact, etc.), user account management, a forum, a picture gallery, and maybe a research document material area (with the latest science about manatees). Pretty simple, and a lot of it would be static, but you can start to see the breakdown.

IndexController - handles about page, privacy policy, generic static content.

UserController - handles account creation, logging in/out, preferences

PictureController - display pictures, handle uploads

ForumController - probably not much, I'd try to integrate an external forum, which would mean I wouldn't need much functionality here.

LibraryController - show lists of recent news and research

HugAManateeController - virtual manatee hugging in real-time over HTTP

That probably gives you at least a basic separation. If you find a controller becoming extremely large, it's probably time to break down the business domain into separate controllers.

It will be different for every project, so a little planning goes a long way towards what kind of architectural structure you'll have.

Web MVC can get very subjective, as it is quite different from a MVC model where your application has state. I try to keep major functionality out of Controllers when dealing with web apps. I like them to instantiate a few objects or models, run a couple of methods based on the action being taken, and collect some View data to pass off to the View once it's done. The simpler the better, and I put the core business logic into the models, which are supposed to be representative of the state of the application.

Hope that helps.