A Typical CakePHP Request
We’ve covered the basic ingredients in CakePHP, so let’s look at
how objects work together to complete a basic request. Continuing
with our original request example, let’s imagine that our friend
Ricardo just clicked on the “Buy A Custom Cake Now!” link on a
CakePHP application’s landing page.
Flow diagram showing a typical CakePHP request
Figure: 2. Typical CakePHP Request.
Black = required element, Gray = optional element, Blue = callback
- Ricardo clicks the link pointing to
http://www.example.com/cakes/buy, and his browser makes a request
to your web server.
- The Router parses the URL in order to extract the parameters for
this request: the controller, action, and any other arguments that
will affect the business logic during this request.
- Using routes, a request URL is mapped to a controller action (a
method in a specific controller class). In this case, it’s the
buy() method of the CakesController. The controller’s
beforeFilter() callback is called before any controller action
logic is executed.
- The controller may use models to gain access to the
application’s data. In this example, the controller uses a model to
fetch Ricardo’s last purchases from the database. Any applicable
model callbacks, behaviors, and DataSources may apply during this
operation. While model usage is not required, all CakePHP
controllers initially require at least one model.
- After the model has retrieved the data, it is returned to the
controller. Model callbacks may apply.
- The controller may use components to further refine the data or
perform other operations (session manipulation, authentication, or
sending emails, for example).
- Once the controller has used models and components to prepare
the data sufficiently, that data is handed to the view using the
controller’s set() method. Controller callbacks may be applied
before the data is sent. The view logic is performed, which may
include the use of elements and/or helpers. By default, the view is
rendered inside a layout.
- Additional controller callbacks (like
afterFilter) may be
applied. The complete, rendered view code is sent to Ricardo’s