How can I use doctrine method inside my service (Symfony 4)?

Question

I created my first own service in Symfony :

// src/Service/PagesGenerator.php

namespace App\Service;

class PagesGenerator
{
    public function getPages()
    {

      $page = $this->getDoctrine()->getRepository(Pages::class)->findOneBy(['slug'=>$slug]);

        $messages = [
            'You did it! You updated the system! Amazing!',
            'That was one of the coolest updates I\'ve seen all day!',
            'Great work! Keep going!',
        ];

        $index = array_rand($messages);

        return $messages[$index];
    }
}

But I get the error message:

Attempted to call an undefined method named "getDoctrine" of class "App\Service\PagesGenerator".

I tried then to add in my services.yaml:

PagesGenerator:
    class: %PagesGenerator.class%
    arguments:
      - "@doctrine.orm.entity_manager"

But then I get the error message:

The file "/Users/work/project/config/services.yaml" does not contain valid YAML in /Users/work/project/config/services.yaml (which is loaded in resource "/Users/work/project/config/services.yaml").

Symfony is working with the magic pattern called Dependency Injection. Instead of giving any argument to your service in `services.yaml`, call `__construct(EntityManagerInterface $em)` in your service and let Symfony inject your entity manager. It's much clearer in my opinion. — GasKa, Mar 05 '19 at 10:06
@GasKa Thank you very much. This sounds really good. Can you give an example. I tried to put this line into my service but I get the error `syntax error, unexpected '$em' ` — peace_love, Mar 05 '19 at 10:09
I think you used `$em` instead of `$this->em`. Also, you have to declare this property for your service before `__construct()`. — GasKa, Mar 05 '19 at 10:10
@GasKa Ok, I am not exactly knowing how to do it, but I try and let you know if it worked — peace_love, Mar 05 '19 at 10:12
I'll make a reply instead of comment for that. Check it out in few minutes. — GasKa, Mar 05 '19 at 10:13
As I said my answer in your previous question: read the documentation. Using Autowiring is part of the Symfony Best Practices. — Stephan Vierkant, Mar 05 '19 at 12:04
@StephanVierkant Yes but first I needed to figure out where to create the class. So I did a tutorial and wanted to get the tutorial work and understand, before I go to the next step understand "autowiring" — peace_love, Mar 05 '19 at 12:11

score 11 · Accepted Answer · answered Mar 05 '19 at 10:16

So, in comments I was saying that is better to let Symfony doing his job and autowiring EntityManager. This is what you should do. Also, can you tell us what Symfony version are you using and if autowiring is enabled (check services.yaml for that)?

<?php

namespace App\Service;

use Doctrine\ORM\EntityManagerInterface;

class PagesGenerator
{
    public function __construct(EntityManagerInterface $em) {
        $this->em = $em;
    }

    public function getPages()
    {

      $page = $this->em->getRepository(Pages::class)->findOneBy(['slug'=>$slug]);

        $messages = [
            'You did it! You updated the system! Amazing!',
            'That was one of the coolest updates I\'ve seen all day!',
            'Great work! Keep going!',
        ];

        $index = array_rand($messages);

        return $messages[$index];
    }
}

That sounds about right but what'd happen if i need to call another Manager to get my Repository? since EntityManagerInterface doesn't have a getManager() attribute i can only call the repository from the 'default'. If i try to do a $this->getDoctrine() from a Service i get an error :: Call to a member function has() on null — SpicyTacos23, Dec 21 '20 at 16:29

score 3 · Answer 2 · answered Mar 05 '19 at 10:26

With Symfony 4 and the new autowiring you can easily inject certain number of class

To find out, which classes/interface you can use for autowiring, use this command:

bin/console   debug:autowiring

We are going to use this one :

Doctrine\ORM\EntityManagerInterface (doctrine.orm.default_entity_manager)

So let's make it, add this just before getPages function

/**
 * @var EntityManagerInterface
 */
private $em;

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

Then you can use it like this:

  $page = $this->em->getRepository(Pages::class)->findOneBy(['slug'=>$slug]);

Hope it helps !

Noman · Answer 3 · 2019-03-05T10:17:49.840

make sure you use proper indent using "spaces" for YAML.

A YAML file use spaces as indentation, you can use 2 or 4 spaces for indentation, but no tab read more about this

Before symfony 3.3

for example we have service sms_manager in AppBundle/FrontEndBundle/Services

services:
    AppBundle.sms_manager:
        class: AppBundle\FrontEndBundle\Services\SmsManager
        arguments: [ '@service_container' ,'@doctrine.orm.entity_manager' ]

then your service can receive your arguments in constructor

<?php

namespace AppBundle\FrontEndBundle\Services;

use Symfony\Component\DependencyInjection\ContainerInterface as Container;

class SmsManager {
    private $container;
    private $DM;

    public function __construct( Container $container, \Doctrine\ORM\EntityManager $DM ) 
    {
        $this->container = $container;
        $this->DM        = $DM;
    }

    /**
    * @return \Doctrine\ORM\EntityManager
    */

    public function getDoctrine() {
      return $this->DM;
    }

}

With Symfony 3.3 or more,

Is there a way to inject EntityManager into a service

use Doctrine\ORM\EntityManagerInterface

class PagesGenerator
{
    private $em;

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

    // ...
}

I know that it's not recommended anymore to inject your container. But this is recommended starting with Symfony 4.x. Anyway, avoid this — GasKa, Mar 05 '19 at 10:08
Correctly, I assumed he has Symfony 3.x or Symfony 4.x and everything works as I said. I saw that you edited your post. Good! Let's see his reply firstly — GasKa, Mar 05 '19 at 10:17

How can I use doctrine method inside my service (Symfony 4)?

3 Answers3