61 lines
1.8 KiB
Markdown
61 lines
1.8 KiB
Markdown
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---
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date: 2025-07-11
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title: Easier dependency injection with autowiring
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permalink: /daily/2025/07/11/easier-dependency-injection-autowiring
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---
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Dependency injection is, as the name suggests, the approach of injecting dependencies into a class - usually within a `__construct` method.
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This makes code less coupled and easier to test.
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In a Drupal application, that usually means not using the static methods on `\Drupal` when fetching dependencies.
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This is an example from my website:
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```php
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<?php
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readonly final class PodcastNodeRepository {
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private NodeStorageInterface $nodeStorage;
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public function __construct(EntityTypeManagerInterface $entityTypeManager) {
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$this->nodeStorage = $entityTypeManager->getStorage('node');
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}
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}
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```
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The `EntityTypeManagerInterface` dependency is injected and used to get the node storage class, which is used in another method to find the podcast episode nodes.
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For this to work with the dependency injection container, I need to add the class as a service, including its arguments so they can be injected:
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```yaml
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# opd_podcast.services.yml
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services:
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Drupal\opd_podcast\Action\GetNextPodcastEpisodeNumber:
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arguments:
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- '@entity_type.manager'
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```
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But, this means you need to update this file if any dependencies change.
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Wouldn't it be better to do this automatically?
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Usually, it can with autowiring.
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Instead of `arguments`, add `autowire: true` and Drupal will try to automatically inject the dependencies for you:
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```yaml
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# opd_podcast.services.yml
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services:
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Drupal\opd_podcast\Action\GetNextPodcastEpisodeNumber:
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autowire: true
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Drupal\opd_podcast\Repository\PodcastNodeRepository:
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autowire: true
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```
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Now, if dependencies change, you don't need to update the services file - making it easier and quicker.
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