Laravel macros allow developers to add custom functionality to Laravel's core classes or even their own classes. They are simple and easy to use, and provide a way to extend Laravel's functionality without modifying the underlying code.

Macros can be defined for a wide range of classes, including Eloquent models, collections, and request and response classes. They are a powerful tool that enables developers to write cleaner, more concise code.

    
    Request::macro('hello', function ($name) {
        echo 'Hello ' . $name;
    });

    Request::hello('World'); // outputs "Hello World"
    

A more practical example of a Request macro would be detecting the domain base name

    
    Request::macro('baseDomain', function ($domain) {
        return Str::is($domain . '.*', $this->root());
    });

    Request::baseDomain('facebook') // returns true for facebook.com
    Request::baseDomain('dev') // returns true for dev.to
    

Defining macros for your Laravel application in a service provider is a good practice. While the AppServiceProvider's boot() method is a great starting point, it can become cluttered over time. To avoid this, you can create a MacrosServiceProvider and register it in the config/app.php file. If your macros are related, you can group them into a separate service provider, such as the TldAwareServiceProvider which houses TLD-related macros.

Available class to define macros

• Illuminate\Cache\Repository
• Illuminate\Console\Scheduling\Event
• Illuminate\Database\Eloquent\Builder
• Illuminate\Database\Eloquent\Relation
• Illuminate\Database\Query\Builder
• Illuminate\Filesystem\Filesystem
• Illuminate\Foundation\Testing\TestResponse
• Illuminate\Http\RedirectResponse
• Illuminate\Http\Request
• Illuminate\Http\UploadedFile
• Illuminate\Routing\ResponseFactory
• Illuminate\Routing\Router
• Illuminate\Routing\UrlGenerator
• Illuminate\Support\Arr
• Illuminate\Support\Collection
• Illuminate\Support\Str
• Illuminate\Translation\Translator
• Illuminate\Validation\Rule