Implements single action controller

[rizqyhi]

Background

Dicoding is already using ADR pattern for quite long time. This pattern maps every single route to one action controller. Currently we hard-coded the method name on the route definition, even the method name is static. Take a look below (notice the action method).

Route::get('/users', ['uses' => 'UsersIndexAction@action']);
Route::get('/users/{id}', ['uses' => 'UsersShowAction@action']);

The problem with that syntax is it's quite hard to navigate to the action class. Usually we'll block the class name (e.g. UsersIndexAction) and trigger file search feature. Imagine if we can click-follow the action classes when we reference them using ::class syntax, like:

Route::get('/users', ['uses' => UsersIndexAction::class]);
Route::get('/users/{id}', ['uses' => UsersShowAction::class]);

Solution

Laravel introduced single action controller when version 5.3 released. The base idea is using default method for the controller, which is magic method __invoke. So when a developer defines a route action without method name (or by referencing the class directly), the router will dispatch the request to __invoke method automatically.

This PR tries to backport that feature to Laravel 4.2.

References:

• [5.3] Allow callable classes as route actions to support ADR out of the box laravel/framework#14059
• [5.3] Support route caching for invokable-actions laravel/framework#14065