laravel：Route :: group - 如何理解:: here的语法。 因为Route类中没有静态函数`group`

Question

In laravel i am not able to understand what :: means w.r.t the code Route:group or Route:get etc.

As per my understanding :: is used to use static methods from a class.

I check the Route class. but there are no such static methods called group or get. So how to understand.

Of course i need not uderstand that for the starting my app. But to understand the syntax is good always. I am using phpstorm. Generally i can figure out the links of functions and classes. I tried to look for group or get it says not declared.

Answer 1

When you use Route::method() like that you're using what's called a "facade". The Route class is the facade in this context.

If you take a look at Illuminate\Support\Facades\Route you'll see that it provides a single static method called getFacadeAccessor, which returns a string router. It's this string that references an instance of the Illuminate\Routing\Router class in the IoC container.

During it's setup Laravel creates an instance of this class and stores it with router as kind of like a key.

So when you do Route::get(...), under the hood Laravel is using the facade accessor to find an instance of the Router class that's already been created and calls the get method on it. It uses dynamic programming to achieve this, have a look at the Illuminate\Support\Facades\Facade class for details of what's going on there, in particular the __callStatic method which is where it all starts.

So, calling Route::get():

• You're actually calling Illuminate\Support\Facades\Route::get
• No such method exists on that class, or the Facade class it extends, so the __callStatic method is run.
• The underlying Facade class calls static::getFacadeRoot() which if you follow the logic, will get you an instance of Illuminate\Routing\Router
• Finally, the __callStatic method calls $instance->$method(...$args); where $instance is the instance of the router, and $method is get and $args is what you passed to Route::get(...);
• So when you call Route::get('route', 'Controller@method'); you actually end up calling get('route', 'Controller@method') on an instance of Illuminate\Routing\Router. Notice, you're not actually calling a static method.