Understanding of service container, service provider and facade of laravel

Service container , There are some causal relationships between service providers and facade , To understand one alone , It's not easy to understand
Personal understanding , We create a new class or an interface to provide some kind of service , There are three objects , service （ That is, the newly created class or interface ）, Service providers （ That is to say laravel Of ServiceProvider）, Containers （ That is to say container app()）

We go through Service providers , Put one service Sign up to In the container

Containers

That goes without saying laravel Of app It's a container , have access to app() To get the container object

service

Let's create a new service , In fact, it is a class or interface defined by itself （ But generally speaking, a service should be an interface ）

We create a Animal Interface , And use Cat To achieve it , As a Service!

<?php
namespace App\Libs\MyLib;

interface Animal{
    

    public function jump();

    public function run();
}

<?php
namespace App\Libs\MyLib;

class Cat implements Animal{
    

    public function jump()
    {
    
        dd("this is the Cat jump");
    }

    public function run()
    {
    
        dd("this is the Cat run");
    }
}

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There is a service on it , At this point, there must be a service provider （ Used to bind containers and services （ Also receive registration ））

Service providers

laravel Create a service provider Use php artisan make:provider XXXServiceProvider.php

After success , There will be one more in the directory Service provider classes

We are register Zhongba Cat Bind to container

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above , The service is bound to the container through the service provider , We still can't use it at this time , We're still one step away , To register a service provider with laravel In the configuration file

Through the above operations , We bind the service to the container , And the framework will be configured accordingly at startup
So how do we use our registered services ？

The above ways , Service objects can be taken from the container

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The above methods extract the service object Is it a little too long to write , Too annoying. , Do we have a simpler way to get objects , At this point, I will talk about Appearance
to glance at vendor/laravel/framework/src/iiiuminate/support/facades The files under the , They are all facade documents , We can Write your own template Facade class

Similarly, we can register an alias for the facade

Now we can use The facade uses static method calls to Method called , （ Be careful , Facade is only useful for methods , Calling properties has no effect ）