Symfony 4.1 components - Dependency Injection issues

问题

I'm refactoring old application in PHP.

I'm trying to use Symphony dependency injection component to inject services into controllers (or other services), but I don't know how to achieve this, because symphony documentation is more prepared for using framework, than framework components.

I already have my own Kernel, Container that contains all services and controllers (controllers are registered as services already). My controllers extending AbstractController from symfony/frameworkbundle. So the only thing I can do now is:

Get service from container by $this->container->get('service_id'), but if service in constructor will have class as parameter

public function __constructor(SomeClass $someClass)

then I'm getting this exception:

The "App\V2\Service\TestService" service or alias has been removed or inlined when the container was compiled. You should either make it public, or stop using the container directly and use dependency injection instead.

If I change configuration to make all services public, then:

Too few arguments to function APP\V2\Service\TestService::__construct(), 0 passed and exactly 1 expected

I prepare a gist, to have better view what I'm talking about: https://gist.github.com/miedzwin/49bac1cc1d5270d3ba1bfcf700abf864

Can someone help me a bit with DI implementation using Symfony components (not Symfony framework)? Good working example would be enough. Or just please put your remarks to my gist, I try to fix this.

回答1:

Symfony 4/5 Autowiring way

From your question and comments I think all you need to do is fix autowiring.

Symfony 4-way is simple: autowire all services and parameters, no manual setup (if possible).

To apply that to your example, this would be the best config to fit your needs and Symfony 4:

services:
    _defaults:
        # pass service dependencies to constructors by default
        autowire: true

        # add known tags (for commands, event subscribers etc) by default
        autoconfigure: true
        
        # to make using tests, bin files and another simpler
        public: true

        # autowiring of string/array/int parameters to constructors
        # this fixes cases like "argument "$facebookUserId" of method "__construct()" has no type-hint, you should configure its value explicitly"
        bind:
            # $constructorVariableName: %parameter% in config
            $facebookUserId: '%facebook_user_id%'

    APP\V2\:
        resource: '../src/app/V2/*'
        exclude: '../src/app/V2/{Script, Trait}'

    # symfony services - you still have to setup 3rd paryt services manually
    Symfony\Component\DependencyInjection\ParameterBag\ContainerBag:
        arguments:
            - '@service_container'
    # ...

Where to Continue Reading

• Passing parameters to services
• How to refactor to new Dependency Injection features in Symfony 3.3

回答2:

https://symfony.com/doc/current/service_container.html#fetching-and-using-services

You need to change default configuration for your service to make them publics :

services:
    _defaults:
        public: true

But a more elegant way to access services is to inject them in controller actions :

public function myAction(Request $request, TestService $service)

来源：https://stackoverflow.com/questions/52221321/symfony-4-1-components-dependency-injection-issues