What are invokable controllers?

Invokable controllers are a special type of controller in Laravel that allow you to define a single __invoke() method to handle a route instead of defining multiple action methods.

In Laravel, a controller is a PHP class that handles HTTP requests and manages the application's response. An invokable controller is a special type of controller in Laravel that allows you to define a single __invoke() the method instead of defining multiple action methods like index(), store(), show() etc.

Invokable controllers are supported in Laravel 5.3 or later versions. So, if you're using a version of Laravel earlier than 5.3, you won't be able to use invokable controllers.

Using an invokable controller, you can define a single action for a particular route, and Laravel will automatically call the __invoke() method when that route is requested. This can be useful when you have a simple action to perform, and you don't want to create a separate method in your controller for it.

To create an invokable controller, you need to define a class with a __invoke() method. Here's an example:

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ExampleController extends Controller
{
    public function __invoke(Request $request)
    {
        return "Hello, World!";
    }
}

In the example above, we have created an invokable controller called ExampleController. It has a single __invoke() method that returns the string "Hello, World!".

To use this controller, you can define a route like this:

Route::get('/example', ExampleController::class);

In this route definition, we have specified the ExampleController class as the controller for the /example route. When a user visits this route, Laravel will automatically call the __invoke() method on the ExampleController class and return the "Hello, World!" string.

In conclusion, an invokable controller in Laravel is a convenient way to define a single action for a particular route, without having to create multiple methods in your controller. It can make your code more concise and easier to read, and can help you build applications more quickly.