Add doc about actions

docs/07. Cookbook.md

@@ -191,6 +191,81 @@ class CustomUserHydrator extends \Zend\Stdlib\Hydrator\ClassMethods
 You finally just need to add this custom hydrator to the hydrator plugin manager, and writing the corresponding
 factory.
 
+## How to deal with actions?
+
+While REST architecture simplifies the creation of APIs, going "the RESTful way" at all costs is often a bad idea. An
+example is actions. This does not map well to a REST architecture: think about a post that you want to like or unlike.
+
+If you want to go 100% RESTful, you have two choices: you could either use a custom HTTP verb (like LIKE and UNLIKE), but
+this is not supported by all browsers and CDN, or you could go with a "like" sub-resources, so you could add a like
+using the following URL: POST `posts/4/likes` and removing it using the following URL: DELETE `posts/4/likes/64`.
+
+However, this really complicates your back-end for very few benefits. In those cases, the simplest is to use simpler
+actions. ZfrRest does not provide any mechanism out-of-the box, so what you should do is simply using standard
+controllers that extend `Zend\Mvc\Controller\AbstractActionController`:
+
+```php
+use Zend\Mvc\Controller\AbstractActionController;
+
+class LikePostController extends AbstractActionController
+{
+    public function likeAction()
+    {
+        // Do things
+    }
+
+    public function unlikeAction()
+    {
+        // Do things
+    }
+}
+```
+
+Then, define specific routes in your config files:
+
+```php
+'router' => [
+    'routes' => [
+        'action-posts' => [
+            'type'    => 'Segment',
+            'options' => [
+                'route'    => '/posts/:post_id',
+                'defaults' => [
+                    'controller' => LikePostController::class
+                ],
+                'constraints' => [
+                    'post_id' => '[0-9]+'
+                ]
+            ],
+            'priority'     => 2, // Make sure it's evaluated BEFORE REST route
+            'child_routes' => [
+                'like' => [
+                    'type'    => 'Literal',
+                    'options' => [
+                        'route'    => '/like',
+                        'defaults' => [
+                            'action' => 'like'
+                        ]
+                    ]
+                ],
+
+                'unlike' => [
+                    'type'    => 'Literal',
+                    'options' => [
+                        'route'    => '/unlike',
+                        'defaults' => [
+                            'action' => 'unlike'
+                        ]
+                    ]
+                ]
+            ]
+        ]
+    ]
+]
+```
+
+> Please note the priority parameter. This is used so that those routes are actually evaluated BEFORE any REST routes.
+
 ## Tuning ZfrRest for production
 
 For maximum performance, here are a few best practices:

docs/README.md

@@ -44,7 +44,8 @@ If you are looking for some information that is not listed in the documentation,
     4. [How to specify a custom input filter?](/docs/07. Cookbook.md)
     5. [How to filter a collection using query params?](/docs/07. Cookbook.md)
     6. [How to serialize custom data that do not belong to the entity?](/docs/07. Cookbook.md)
-    7. [Tuning ZfrRest for production](/docs/07. Cookbook.md)
+    7. [How to deal with actions?](/docs/07. Cookbook.md)
+    8. [Tuning ZfrRest for production](/docs/07. Cookbook.md)
 
 8. [Mapping reference](/docs/08. Mapping reference.md)
     1. [Annotations](/docs/08. Mapping reference.md)