Exposing media metadata in API responsesfor Drupal 8 , 9 , 10 , and 11

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8.x , 9.x , 10.x , 11.x

In our journey towards building a comprehensive headless Drupal application, mastering API responses to include rich media metadata plays a pivotal role. Metadata provides context to the raw media files, enabling advanced features like search, filtering, and curation.

What is Media Metadata?

Media metadata consists of additional information about media files such as images, videos, or documents. In a Drupal context, metadata might include:

  • File name and size
  • Mime type
  • Uploaded by (user information)
  • Alt text and captions for accessibility
  • Tags and categories for organizing content

Exposing Metadata with JSON:API

The JSON:API module in Drupal provides an efficient way to expose media metadata by default, but customization might be needed based on your specific needs.

Step 1: Enable JSON:API

Ensure the JSON:API module is enabled on your site:

drush en jsonapi -y

This module automatically exposes all available entities (including media) at standardized endpoints like /jsonapi/media/{media_type}.

Step 2: Define the Metadata to Expose

By default, JSON:API exposes all public fields defined in the Drupal UI. To customize which metadata fields to include, you can leverage View Modes or create a custom REST resource.

Step 3: Customize Metadata with View Modes

Modify which fields to include in the API with View Modes:

  1. Create or edit a View Mode under Structure > Media types > Manage display.
  2. Select the View Mode (e.g., Full content) you want to adjust.
  3. Configure fields to show or hide specific metadata, such as contributor, file size, etc.

Step 4: Using Sparse Fieldsets for API Requests

You can specify which fields to return using the sparse fieldsets feature in JSON:API:


GET /jsonapi/media/image?fields[media--image]=title,field_media_image,field_tags

This request fetches media with only the title, image, and tags metadata, reducing payload size and complexity.

Defining Custom REST Resources

For more complex metadata requirements, consider defining custom REST resources to handle advanced logic or data manipulation before exposing through APIs.

Follow the steps from our previous lesson on Defining Custom REST Resources to structure your responses as needed.

Testing API Responses

Use tools like Postman or cURL to test and validate your JSON:API endpoints:


curl -X GET "http://example.com/jsonapi/media/image"

Verify that the API returns the expected metadata format, and check for any performance implications.

Best Practices

Tip: Regularly audit the metadata exposed by your APIs to ensure only necessary data is shared. This helps mitigate security risks and optimizes performance.

Conclusion and What’s Next?

Exposing media metadata in your API responses enriches the front-end user experience with detailed context, essential for features like search and personalization. By mastering this, you're equipping your headless Drupal architecture with powerful capabilities.

In our upcoming lesson, we'll delve into "Advanced Caching Strategies for API Endpoints", helping you to further refine and boost the performance of your headless CMS environment.