How do I read from parameters.yml in a controller

问题:

I have put a couple of custom variables in my app/config/parameters.yml.

parameters:
    api_pass: apipass
    api_user: apiuser

I need to access these from my controller, and have tried to fetch them with

$this->get('api_user');

from within my controller file. When I try this, I get this error message:

You have requested a non-existent service "api_user".

What is the correct way to do this?

回答1:

In Symfony 2.6 and older versions, to get a parameter in a controller - you should get the container first, and then - the needed parameter.

$this->container->getParameter('api_user');

This documentation chapter explains it.

While $this->get() method in a controller will load a service (doc)

In Symfony 2.7 and newer versions, to get a parameter in a controller you can use the following:

$this->getParameter('api_user');

回答2:

The Clean Way

Since 2017 and Symfony 3.3 + 3.4 there is much cleaner way - easy to setup and use.

Instead of using container and service/parameter locator anti-pattern, you can pass parameters to class via it's constructor. Don't worry, it's not time-demanding work, but rather setup once & forget approach.

How to set it up in 2 steps?

1. app/config/services.yml

# config.yml

# config.yml
parameters:
    api_pass: 'secret_password'
    api_user: 'my_name'

services:
    _defaults:
        autowire: true
        bind:
            $apiPass: '%api_pass%'
            $apiUser: '%api_user%'

    App\:
        resource: ..

2. Any Controller

<?php declare(strict_types=1);

final class ApiController extends SymfonyController
{
    /**
     * @var string 
     */
    private $apiPass;

    /**
     * @var string
     */
    private $apiUser;

    public function __construct(string $apiPass, string $apiUser)
    {
        $this->apiPass = $apiPass;
        $this->apiUser = $apiUser;
    }

    public function registerAction(): void
    {
        var_dump($this->apiPass); // "secret_password"
        var_dump($this->apiUser); // "my_name"
    }
}

Instant Upgrade Ready!

In case you use older approach, you can automate it with Rector.

Read More

This is called constructor injection over services locator approach.

To read more about this, check my post How to Get Parameter in Symfony Controller the Clean Way.

(It's tested and I keep it updated for new Symfony major version (5, 6...)).

回答3:

I send you an example with swiftmailer:

parameters.yml

recipients: [email1, email2, email3]

services:

your_service_name:
        class: your_namespace
        arguments: ["%recipients%"]

the class of the service:

protected $recipients;

public function __construct($recipients)
{
    $this->recipients = $recipients;
}

回答4:

You can use:

public function indexAction()
{
   dump( $this->getParameter('api_user'));
}

For more information I recommend you read the doc :

http://symfony.com/doc/2.8/service_container/parameters.html

回答5:

In Symfony 4, you can use the ParameterBagInterface:

use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;

class MessageGenerator
{
    private $params;

    public function __construct(ParameterBagInterface $params)
    {
        $this->params = $params;
    }

    public function someMethod()
    {
        $parameterValue = $this->params->get('parameter_name');
        // ...
    }
}

and in app/config/services.yaml:

parameters:
    locale: 'en'
    dir: '%kernel.project_dir%'

It works for me in both controller and form classes. More details can be found in the Symfony blog.

回答6:

You can also use:

$container->getParameter('api_user');

Visit http://symfony.com/doc/current/service_container/parameters.html