Controllers

class Cake\Controller\Controller

Controllers are the ‘C’ in MVC. After routing has been applied and the correct controller has been found, your controller’s action is called. Your controller should handle interpreting the request data, making sure the correct models are called, and the right response or view is rendered. Controllers can be thought of as middle layer between the Model and View. You want to keep your controllers thin, and your models fat. This will help you reuse your code and makes your code easier to test.

Commonly, a controller is used to manage the logic around a single model. For example, if you were building a site for an online bakery, you might have a RecipesController managing your recipes and an IngredientsController managing your ingredients. However, it’s also possible to have controllers work with more than one model. In CakePHP, a controller is named after the primary model it handles.

Your application’s controllers extend the AppController class, which in turn extends the core Controller class. The AppController class can be defined in src/Controller/AppController.php and it should contain methods that are shared between all of your application’s controllers.

Controllers provide a number of methods that handle requests. These are called actions. By default, each public method in a controller is an action, and is accessible from a URL. An action is responsible for interpreting the request and creating the response. Usually responses are in the form of a rendered view, but there are other ways to create responses as well.

The App Controller

As stated in the introduction, the AppController class is the parent class to all of your application’s controllers. AppController itself extends the Cake\Controller\Controller class included in CakePHP. AppController is defined in src/Controller/AppController.php as follows:

namespace App\Controller;

use Cake\Controller\Controller;

class AppController extends Controller
{
}

Controller attributes and methods created in your AppController will be available in all controllers that extend it. Components (which you’ll learn about later) are best used for code that is used in many (but not necessarily all) controllers.

You can use your AppController to load components that will be used in every controller in your application. CakePHP provides a initialize() method that is invoked at the end of a Controller’s constructor for this kind of use:

namespace App\Controller;

use Cake\Controller\Controller;

class AppController extends Controller
{

    public function initialize()
    {
        // Always enable the CSRF component.
        $this->loadComponent('Csrf');
    }

}

In addition to the initialize() method, the older $components property will also allow you to declare which components should be loaded. While normal object-oriented inheritance rules apply, the components and helpers used by a controller are treated specially. In these cases, AppController property values are merged with child controller class arrays. The values in the child class will always override those in AppController.

Request Flow

When a request is made to a CakePHP application, CakePHP’s Cake\Routing\Router and Cake\Routing\Dispatcher classes use Connecting Routes to find and create the correct controller instance. The request data is encapsulated in a request object. CakePHP puts all of the important request information into the $this->request property. See the section on Request for more information on the CakePHP request object.

Controller Actions

Controller actions are responsible for converting the request parameters into a response for the browser/user making the request. CakePHP uses conventions to automate this process and remove some boilerplate code you would otherwise need to write.

By convention, CakePHP renders a view with an inflected version of the action name. Returning to our online bakery example, our RecipesController might contain the view(), share(), and search() actions. The controller would be found in src/Controller/RecipesController.php and contain:

// src/Controller/RecipesController.php

class RecipesController extends AppController
{
    public function view($id)
    {
        // Action logic goes here.
    }

    public function share($customerId, $recipeId)
    {
        // Action logic goes here.
    }

    public function search($query)
    {
        // Action logic goes here.
    }
}

The template files for these actions would be src/Template/Recipes/view.ctp, src/Template/Recipes/share.ctp, and src/Template/Recipes/search.ctp. The conventional view file name is the lowercased and underscored version of the action name.

Controller actions generally use Controller::set() to create a context that View uses to render the view layer. Because of the conventions that CakePHP uses, you don’t need to create and render the view manually. Instead, once a controller action has completed, CakePHP will handle rendering and delivering the View.

If for some reason you’d like to skip the default behavior, you can return a Cake\Network\Response object from the action with the fully created response.

In order for you to use a controller effectively in your own application, we’ll cover some of the core attributes and methods provided by CakePHP’s controllers.

Interacting with Views

Controllers interact with views in a number of ways. First, they are able to pass data to the views, using Controller::set(). You can also decide which view class to use, and which view file should be rendered from the controller.

Setting View Variables

Cake\Controller\Controller::set(string $var, mixed $value)

The Controller::set() method is the main way to send data from your controller to your view. Once you’ve used Controller::set(), the variable can be accessed in your view:

// First you pass data from the controller:

$this->set('color', 'pink');

// Then, in the view, you can utilize the data:
?>

You have selected <?= h($color) ?> icing for the cake.

The Controller::set() method also takes an associative array as its first parameter. This can often be a quick way to assign a set of information to the view:

$data = [
    'color' => 'pink',
    'type' => 'sugar',
    'base_price' => 23.95
];

// Make $color, $type, and $base_price
// available to the view:

$this->set($data);

Setting View Options

If you want to customize the view class, layout/template paths, helpers or the theme that will be used when rendering the view, you can use the viewBuilder() method to get a builder. This builder can be used to define properties of the view before it is created:

$this->viewBuilder()
    ->helpers(['MyCustom'])
    ->theme('Modern')
    ->className('Modern.Admin');

The above shows how you can load custom helpers, set the theme and use a custom view class.

New in version 3.1: ViewBuilder was added in 3.1

Rendering a View

Cake\Controller\Controller::render(string $view, string $layout)

The Controller::render() method is automatically called at the end of each requested controller action. This method performs all the view logic (using the data you’ve submitted using the Controller::set() method), places the view inside its View::$layout, and serves it back to the end user.

The default view file used by render is determined by convention. If the search() action of the RecipesController is requested, the view file in src/Template/Recipes/search.ctp will be rendered:

namespace App\Controller;

class RecipesController extends AppController
{
// ...
    public function search()
    {
        // Render the view in src/Template/Recipes/search.ctp
        $this->render();
    }
// ...
}

Although CakePHP will automatically call it after every action’s logic (unless you’ve set $this->autoRender to false), you can use it to specify an alternate view file by specifying a view file name as first argument of Controller::render() method.

If $view starts with ‘/’, it is assumed to be a view or element file relative to the src/Template folder. This allows direct rendering of elements, very useful in AJAX calls:

// Render the element in src/Template/Element/ajaxreturn.ctp
$this->render('/Element/ajaxreturn');

The second parameter $layout of Controller::render() allows you to specify the layout with which the view is rendered.

Rendering a Specific Template

In your controller, you may want to render a different view than the conventional one. You can do this by calling Controller::render() directly. Once you have called Controller::render(), CakePHP will not try to re-render the view:

namespace App\Controller;

class PostsController extends AppController
{
    public function my_action()
    {
        $this->render('custom_file');
    }
}

This would render src/Template/Posts/custom_file.ctp instead of src/Template/Posts/my_action.ctp.

You can also render views inside plugins using the following syntax: $this->render('PluginName.PluginController/custom_file'). For example:

namespace App\Controller;

class PostsController extends AppController
{
    public function my_action()
    {
        $this->render('Users.UserDetails/custom_file');
    }
}

This would render plugins/Users/src/Template/UserDetails/custom_file.ctp

Redirecting to Other Pages

Cake\Controller\Controller::redirect(string|array $url, integer $status)

The flow control method you’ll use most often is Controller::redirect(). This method takes its first parameter in the form of a CakePHP-relative URL. When a user has successfully placed an order, you might wish to redirect him to a receipt screen.

public function place_order()
{
    // Logic for finalizing order goes here
    if ($success) {
        return $this->redirect(
            ['controller' => 'Orders', 'action' => 'thanks']
        );
    }
    return $this->redirect(
        ['controller' => 'Orders', 'action' => 'confirm']
    );
}

The method will return the response instance with appropriate headers set. You should return the response instance from your action to prevent view rendering and let the dispatcher handle actual redirection.

You can also use a relative or absolute URL as the $url argument:

return $this->redirect('/orders/thanks');
return $this->redirect('http://www.example.com');

You can also pass data to the action:

return $this->redirect(['action' => 'edit', $id]);

The second parameter of Controller::redirect() allows you to define an HTTP status code to accompany the redirect. You may want to use 301 (moved permanently) or 303 (see other), depending on the nature of the redirect.

If you need to redirect to the referer page you can use:

return $this->redirect($this->referer());

An example using query strings and hash would look like:

return $this->redirect([
    'controller' => 'Orders',
    'action' => 'confirm',
    '?' => [
        'product' => 'pizza',
        'quantity' => 5
    ],
    '#' => 'top'
]);

The generated URL would be:

http://www.example.com/orders/confirm?product=pizza&quantity=5#top

Redirecting to Another Action on the Same Controller

Cake\Controller\Controller::setAction($action, $args...)

If you need to forward the current action to a different action on the same controller, you can use Controller::setAction() to update the request object, modify the view template that will be rendered and forward execution to the named action:

// From a delete action, you can render the updated
// list page.
$this->setAction('index');

Loading Additional Models

Cake\Controller\Controller::loadModel(string $modelClass, string $type)

The loadModel() function comes handy when you need to use a model table/collection that is not the controller’s default one:

// In a controller method.
$this->loadModel('Articles');
$recentArticles = $this->Articles->find('all', [
    'limit' => 5,
    'order' => 'Articles.created DESC'
]);

If you are using a table provider other than the built-in ORM you can link that table system into CakePHP’s controllers by connecting its factory method:

// In a controller method.
$this->modelFactory(
    'ElasticIndex',
    ['ElasticIndexes', 'factory']
);

After registering a table factory, you can use loadModel to load instances:

// In a controller method.
$this->loadModel('Locations', 'ElasticIndex');

Note

The built-in ORM’s TableRegistry is connected by default as the ‘Table’ provider.

Paginating a Model

Cake\Controller\Controller::paginate()

This method is used for paginating results fetched by your models. You can specify page sizes, model find conditions and more. See the pagination section for more details on how to use paginate()

The paginate attribute gives you an easy way to customize how paginate() behaves:

class ArticlesController extends AppController
{
    public $paginate = [
        'Articles' => [
            'conditions' => ['published' => 1]
        ]
    ];
}

Configuring Components to Load

Cake\Controller\Controller::loadComponent($name, $config = [])

In your Controller’s initialize() method you can define any components you want loaded, and any configuration data for them:

public function initialize()
{
    parent::initialize();
    $this->loadComponent('Csrf');
    $this->loadComponent('Comments', Configure::read('Comments'));
}
property Cake\Controller\Controller::$components

The $components property on your controllers allows you to configure components. Configured components and their dependencies will be created by CakePHP for you. Read the Configuring Components section for more information. As mentioned earlier the $components property will be merged with the property defined in each of you controller’s parent classes.

Configuring Helpers to Load

property Cake\Controller\Controller::$helpers

Let’s look at how to tell a CakePHP Controller that you plan to use additional MVC classes:

class RecipesController extends AppController
{
    public $helpers = ['Form'];
}

Each of these variables are merged with their inherited values, therefore it is not necessary (for example) to redeclare the FormHelper, or anything that is declared in your AppController.

Deprecated since version 3.0: Loading Helpers from the controller is provided for backwards compatibility reasons. You should see Configuring Helpers for how to load helpers.

Request Life-cycle Callbacks

CakePHP controllers trigger several events/callbacks that you can use to insert logic around the request life-cycle:

Event List

  • Controller.initialize
  • Controller.startup
  • Controller.beforeRedirect
  • Controller.beforeRender
  • Controller.shutdown

Controller Callback Methods

By default the following callback methods are connected to related events if the methods are implemented by your controllers

Cake\Controller\Controller::beforeFilter(Event $event)

Called during the Controller.initialize event which occurs before every action in the controller. It’s a handy place to check for an active session or inspect user permissions.

Note

The beforeFilter() method will be called for missing actions.

Returning a response from a beforeFilter method will not prevent other listeners of the same event from being called. You must explicitly stop the event.

Cake\Controller\Controller::beforeRender(Event $event)

Called during the Controller.beforeRender event which occurs after controller action logic, but before the view is rendered. This callback is not used often, but may be needed if you are calling Controller\Controller::render() manually before the end of a given action.

Cake\Controller\Controller::afterFilter(Event $event)

Called during the Controller.shutdown event which is triggered after every controller action, and after rendering is complete. This is the last controller method to run.

In addition to controller life-cycle callbacks, Components also provide a similar set of callbacks.

Remember to call AppController‘s callbacks within child controller callbacks for best results:

public function beforeFilter(Event $event)
{
    parent::beforeFilter($event);
}

More on Controllers