Post: Laravel facades vs class aliases

source/_posts/laravel-facades-vs-class-aliases.md

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+---
+title: Laravel facades vs class aliases
+date: 2024-03-26
+excerpt: Diving into the difference between Laravel's facades and class aliases.
+extends: _layouts.post
+section: body
+---
+
+There's a difference between what Laravel calls facades and class aliases. Let's
+take a look at both, how they're different from each other, and how they became
+so intertwined with each other in the public eye.
+
+## Facades
+A facade in Laravel is nothing but _a proxy_ to an object in the service container.
+In other words, if an object is bound to the service container as `'my-service'`,
+you can call methods on that object by using static methods on the following
+facade:
+
+```php
+namespace App\Facades;
+
+use Illuminate\Support\Facades\Facade;
+
+class MyServiceFacade extends Facade
+{
+    public function getFacadeAccessor()
+    {
+	    return 'my-service';
+    }
+}
+```
+
+Notice the `'my-service'` string by which the service is bound to the container.
+When _any_ static method is called on this facade, 
+[the facade's `__callStatic()`magic method](https://github.com/laravel/framework/blob/428f86d2734d7ce4a40b3826bf78500c395b419d/src/Illuminate/Support/Facades/Facade.php#L349-L358) is invoked, the `'my-service'`
+service is retrieved from the container, and your call is forwarded to that
+instance.
+
+You still have to reference the full namespace to this facade (`App\Facades\MyServiceFacade`) 
+when you use it in your application. At least, if you don't also add a class alias.
+
+## Class Aliases
+PHP allows developers to alias _any_ class to _any other name_ using 
+[the `class_alias` function](https://www.php.net/manual/en/function.class-alias.php). For example, say I have a class named `Aang`,
+I could alias it to`BonzuPippinpaddleopsicopolisTheThird` and use it like normal:
+
+```php
+class Aang
+{
+	public static function greet(): string
+	{
+		return 'Flameo!';
+	}
+}
+
+class_alias(Aang::class, 'BonzuPippinpaddleopsicopolisTheThird');
+
+echo BonzuPippinpaddleopsicopolisTheThird::greet(); // Flameo!
+```
+
+You can also alias something to another namespace if you want:
+
+```php
+namespace App {
+    class User
+    {
+        public static function greet(): string
+        {
+            return 'Hello!';
+        }
+    }
+}
+
+namespace {
+    class_alias(App\User::class, 'User');
+
+    echo \User::greet(); // Hello!
+}
+```
+
+This can be useful for using classes with a long FQCN in views, where importing
+classes with `use` statements might not be possible or is just plain ugly.
+
+The most obvious downside is that you lose autocomplete in most IDEs, because your
+IDE can't know when/if the `class_alias()` function has been called at that point
+in your application.
+
+## The Confusion
+Laravel aliases all facades it ships with to their base classname like in the second
+example above. That means
+[all classes in the `Illuminate\Support\Facades` namespace](https://github.com/laravel/framework/tree/428f86d2734d7ce4a40b3826bf78500c395b419d/src/Illuminate/Support/Facades)
+are available as if they were in the global namespace. You can see this happen in your
+own `config/app.php` (the `aliases` key).
+
+I think this default behavior is why a lot of people in the Laravel community have
+conflated facades and class aliases.
+
+Using a namespaced class as if it lives in the global namespace is not only for
+facades. You can alias whatever classes you want in the aforementioned `config/app.php`.
+For example, you might alias `Illuminate\Support\Str` to just `Str` and
+`Illuminate\Support\Number` to `Num` for quick and easy use in views.
+
+## Conclusion
+`\Config` is not a _facade_, it's a class alias for the facade. There is no reason
+why you shouldn't import the full namespace to a facade in PHP-only files.
+
+I generally think that you should import the full namespace 
+(`use Illuminate\Support\Facades\Config`) for facades, and not the alias. I also
+try to limit the use of class aliases in views and opt for the global functions
+Laravel provides instead because aliases don't work with autocomplete in my IDE
+without external tooling.