Using hook_jsonapi_resource_response_alter() for translationsfor Drupal 8 , 9 , 10 , and 11

As you continue developing your headless Drupal application, refining how translations are delivered through JSON:API can significantly enhance multilingual user experiences. In this lesson, we examine how to leverage hook_jsonapi_resource_response_alter() to tailor API responses with translation-specific data, providing flexibility in handling multilingual content.

What is hook_jsonapi_resource_response_alter()?

The hook_jsonapi_resource_response_alter() is a Drupal hook used to modify JSON:API responses before they are sent to the client. This hook is part of Drupal's powerful plugin-based system, allowing developers to customize response data by injecting additional information or modifying existing structures, such as adding translation data.

Why Customize API Responses for Translations?

Customizing JSON:API responses to include translation data ensures your applications can accurately render content based on language preferences. Benefits include:

• Delivering language-specific fields dynamically.
• Providing insights into available content translations.
• Optimizing content strategies for global markets.

Implementing hook_jsonapi_resource_response_alter()

To implement this hook, we will create a custom module. Here's how you can alter JSON:API responses to enhance translation capabilities:

Step 1: Set Up a Custom Module

Create a directory for your custom module with the necessary structure:

drupal/
└── modules/
    └── custom/
        └── translation_alter/
            ├── translation_alter.info.yml
            └── translation_alter.module

In translation_alter.info.yml:

name: 'Translation Alter'
type: module
description: 'Alters JSON:API responses to include translation details.'
core_version_requirement: ^8 || ^9
package: Custom
dependencies:
  - jsonapi

Step 2: Implement the Hook

Now, implement the hook within translation_alter.module:

getEntityTypeId() === 'node' && $bundle === 'article') {
    $data = $response->getResponseData();
    
    // Add available translations to the response data.
    if ($entity->hasTranslation('fr')) {
      $data['data']['attributes']['available_translations'][] = 'fr';
    }
    if ($entity->hasTranslation('es')) {
      $data['data']['attributes']['available_translations'][] = 'es';
    }
    
    $response->setResponseData($data);
  }
}

This code checks if the entity has French and Spanish translations and adds them to the response metadata, visible to API consumers.

Testing Your Custom Translation Hook

Use tools such as Postman or cURL to test your API endpoints and verify the inclusion of translation data:

curl -X GET "http://example.com/jsonapi/node/article/1"

Your modified JSON response should now include language details in the available_translations attribute.

Best Practices

Conclusion and What’s Next?

By using hook_jsonapi_resource_response_alter() for translations, you gain control over how multilingual content is consumed by applications, enhancing the flexibility and capability of your headless Drupal setup.

Next, we'll focus on how to implement "Advanced Translation Management in a Headless Environment", expanding your ability to handle complex multilingual requirements efficiently.