How do I access a module configuration from a service?

Question

I have a module configuration.

modulename.config.yml

modulename:
  core_address: 107.101.xx.yy
  core_port: 153759
  core_user: superuser
  core_pass: superpass

I have a service.

modulename.service.yml

services:
    modulename.my_service:
        class: Drupal\modulename\group\MyService

MyService.php

/**
 * @file
 * Contains \Drupal\modulename\group\MyService.
 */
 
namespace Drupal\modulename\group;
 
/**
 * MyService.
 */
class MyService{

  public function __construct() { }
  
  public function getDemoValue() {
    $config =  \Drupal::config('modulename.my_service');
    $core_port = $config->get('modulename.core_port');
    return $core_port . 'asdf';
  }

}

$core_port is always empty.

How can I access a module configuration from a service it implements?

I am not sure this is relevant, but getDemoValue() is called from different a module.

/**
 * @file
 * Contains \Drupal\anothermodulename\Controller\MyForm.
 */
 
namespace Drupal\anothermodulename\Controller;
 
use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Component\Utility\UrlHelper;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * MyForm.
 */
class MyForm extends FormBase {

  protected $demoService;
  
  /**
   * Class constructor.
   */
  public function __construct($demoService) {
    $this->demoService = $demoService;
  }
  
  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static(
      $container->get('modulename.my_service')
    );
  }

  /**
   * {@inheritdoc}
   */
  public function getFormId() { /** nothing interesting here **/ }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    /** nothing interesting here **/
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function validateForm(array &$form, FormStateInterface $form_state){ /** nothing interesting here **/ }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    // Display result.
    foreach ($form_state->getValues() as $key => $value) {
      drupal_set_message($key . ': ' . $value . '  ' . $this->demoService->getDemoValue()); // i try to print here but didn't happend
    }
  }

}

Answer 1

Use $config = \Drupal::configFactory()->getEditable('modulename.config').

And so on...

$core_port = $config->get('core_port');
$config->set('core_port', 8888)->save();

modulename.config.yml should be more like:

core_address: 107.101.xx.yy
core_port: 153759
core_user: superuser
core_pass: superpass

Answer 2

To read the variables (configs) you'd do this:

$config = \Drupal::config('modulename.my_service');

$core_port = $config->get('modulename.core_port');

To write to the variables (configs) you'd do this:

// Set and save new message value.

$config = \Drupal::service('config.factory')->getEditable('modulename.my_service');
$config->set('modulename.core_port', 153760)->save();

There's an example you can look at in the core module aggregator.

It has a settings form at /core/modules/aggregator/src/Form/SettingsForm.php

and then it adds a route to access the settings form:

aggregator.admin_settings:
  path: '/admin/config/services/aggregator/settings'
  defaults:
    _form: '\Drupal\aggregator\Form\SettingsForm'
    _title: 'Feed aggregator settings'
  requirements:
    _permission: 'administer news feeds'

You could pretty much copy the form into your module and change the variables to match your config.

Generally you'll want to add the config in your service constructor.

namespace Drupal\modulename;

/**
 * Example Service with config.
 */
class MyService {


  /**
   * Drupal's settings manager.
   */
  protected $settings;

  /**
   * Constructor.
   */
  public function __construct() {
    $this->settings = \Drupal::config('modulename.my_service');
  }

}

Then you'd access the variables like this:

$this->settings->get('modulename.core_port');

Answer 3

Given the code shown in the question, there are two errors in MyService::getDemoValue().

• Since the configuration filename is modulename.config.yml, the configuration object should be created with \Drupal::config('modulename.config'), not \Drupal::config('modulename.my_service') which would instead work when the configuration filename is modulename.my_service.yml
• Since none of the configuration values has a name that starts with modulename., the configuration values should be read with (for example) $config->get('core_port'), not $config->get('modulename.core_port')

That is the code to read a configuration object. To alter the configuration values and save them, \Drupal::configFactory()->getEditable('modulename.config') should be used instead of \Drupal::config('modulename.config'). In this case, setting core_port to 888 would be achieved using code similar to the following one.

$config = \Drupal::configFactory()->getEditable('modulename.config');
$config->set('core_port', 8888)
  ->save();

As a side note, Drupal services should use the dependency injection container instead of requiring any Drupal service to the \Drupal class. That is described in Services and Dependency Injection Container.