What's the correct place to share application logic in CakePHP?

Question

I guess simple answer to the question would be a component.

Although I agree, I feel weird having to write a component for something so specific.

For example, let's say I have a table of users. When a user is created, it should form a chain reaction of events, initiating different kinds of data related to the user all around the database. I figured it would be best to avoid directly manipulating the database from different controllers and instead pack all that neatly in a method. However since some logic needs to be accesed separately, I really can't have the whole package in a single method. Instead I thought it would be logical to break it up to smaller pieces(like $userModelOrController->createNew() and $candyStorageModelOrController->createNew()) that only interact with their respective database table.

Now, if the logic is put to the model, it works great until I need to use other models. Of course it's possible, but when compared to loading models in a controller, it's not that simple. It's like a Cake developer telling me "Sure, it's possible if you want to do it that way but that's not how I would do it".

Then, if the logic is put to the controller, I can access other models really easy through $this->loadModel(), but that brings me back to the previously explained situation since I need to be able to continue the chain reaction indefinitely. Accessing other controllers from a controller is possible, but again there doesn't seem to be any direct way of doing so, so I'm guessing I'm still not doing it right.

By using a component this problem could be solved easily, since components are available to every controller I want. But like I wrote at the beginning, it feels awkward to create a component specifically for this one task. To me, components seem more like packages of extra functionality(like the core components) and not something to share controller-specific logic.

Since I'm new to this whole MVC thing, I could've completely misunderstood the concept. Once again, I would be thankful if someone pointed me to the right direction :)

Answer 1

It is deifinitley bugging that CakePHP does not support easly

• accessing another Model from a Model
• accessing a Component from a Model
• accessing any Model from a Component
• having a function accessible both from Controllers and Views (something between Components and Helpers), or accessing a Component from a Helper (or vica-versa)

I mostly ended up adding function to the superclass AppController.

Answer 2

It is clearly stated in the cookbook: "Components are packages of logic that are shared between controllers. If you find yourself wanting to copy and paste things between controllers, you might consider wrapping some functionality in a component."

Answer 3

You can use the AppModel if you want your models to share some logic. If you need to access different models in your model, you can use App::import() or ClassRegistry::init. Now if you want the logic to be available only to some models of your choice, you can use a Behavior or create a different AppModel where only your selected models will inherit.

Answer 4

Probably a better way to implement this is within a plugin. Plugins allow you to encapsulate entire functionality across all parts of MVC into a package which can be pulled in anywhere in your code via the plugin's Helpers, Components, Behaviors. This way,

• you can put the functionality where its most appropriate,
• the logic is kept separate from the rest of your app logic and
• you can enable/disable this functionality as needed.