WARNING: You are browsing the documentation for Symfony 3.3 which is not maintained anymore. Consider upgrading your projects to Symfony 4.1.

Service Method Calls and Setter Injection

3.3 version

Maintained

2.8 3.4 4.1 current 4.2 master

Unmaintained

2.7 3.2 4.0

Service Method Calls and Setter Injection¶

Tip

If you're using autowiring, you can use @required to automatically configure method calls.

Usually, you'll want to inject your dependencies via the constructor. But sometimes, especially if a dependency is optional, you may want to use "setter injection". For example:

namespace AppBundle\Service;

use Psr\Log\LoggerInterface;

class MessageGenerator
{
    private $logger;

    public function setLogger(LoggerInterface $logger)
    {
        $this->logger = $logger;
    }

    // ...
}

To configure the container to call the setLogger method, use the calls key:

YAML

# app/config/services.yml
services:
    AppBundle\Service\MessageGenerator:
        # ...
        calls:
            - method: setLogger
              arguments:
                  - '@logger'

XML

<!-- app/config/services.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        http://symfony.com/schema/dic/services/services-1.0.xsd">

    <services>
        <service id="AppBundle\Service\MessageGenerator">
            <!-- ... -->
            <call method="setLogger">
                <argument type="service" id="logger" />
            </call>
        </service>
    </services>
</container>

PHP

// app/config/services.php
use AppBundle\Service\MessageGenerator;
use Symfony\Component\DependencyInjection\Reference;

$container->register(MessageGenerator::class)
    ->addMethodCall('setLogger', array(new Reference('logger')));

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.