Syncing only changed content via APIsfor Drupal 8 , 9 , 10 , and 11

In this lesson, we delve into optimizing data synchronization between your Drupal backend and frontend applications. We focus on techniques for syncing only changed content using APIs, which enhances your application’s performance by reducing unnecessary data transfer.

Why Sync Only Changed Content?

In a headless CMS setup, transferring only modified content minimizes bandwidth usage, accelerates data operations, and ensures your frontend applications are up-to-date without overwhelming the server with identical data payloads. This approach is crucial for large-scale sites where content updates occur frequently.

Using JSON:API for Efficient Content Synchronization

JSON:API in Drupal provides a standardized way to interact with content, making it possible to track and fetch only modified or new resources through certain techniques such as filtering by timestamps.

Step 1: Enabling and Configuring JSON:API

1. First, ensure that the JSON:API module is enabled in your Drupal installation:

   drush en jsonapi -y

2. Navigate to Extend and confirm that JSON:API and JSON:API Extras are activated for further customization.
3. Verify that your JSON:API endpoints are accessible:

   https://example-drupal-site.com/jsonapi/node/article

Step 2: Implementing Content Filtering by Change

Employ the Last Changed timestamp to filter resources. This method involves using the changed field from your content types:

To fetch only updated content, append a query parameter with a condition for the changed field greater than a certain timestamp:

GET /jsonapi/node/article?filter[changed][value]>=1609459200

Step 3: Storing Timestamps on the Frontend

Your frontend application should store the timestamp of the latest sync. On the next sync attempt, this timestamp is used to request only content changed after this point.

Optimizing with GraphQL

If your setup uses GraphQL, similar logic applies. Ensure you construct queries to fetch only modified data:

Example GraphQL Query:

    query {
      nodeQuery(filter: {conditions: [{field: "changed", value: "1609459200", operator: ">"}]}) {
        entities {
          ...on NodeArticle {
            title
            body {
              value
            }
            changed
          }
        }
      }
    }
    

Handling Data and Error Management

Implement error handling by managing HTTP response statuses and adding retry logic in case of connectivity issues. Also, consider caching and diff strategies for large content sets.

Conclusion and What's Next?

Syncing only changed content using Drupal's APIs increases the efficiency of your headless Drupal setup, leading to more responsive applications and satisfied users. By reducing data redundancies, you ensure that every API call is meaningful and resource-efficient.

In our next lesson, we will explore Setting Up Drupal and Frontend Deployments, guiding you through automating deployments to streamline your project's lifecycle from development to production. Stay engaged!