mirrorSchools()

mirrorSchools, generateMirrorDocFunction

Function Name

mirrorSchools

Trigger

This Cloud Function is triggered by document write events (create, update, delete) on Firestore documents located at schools/{documentId}. The function is set up to handle changes to any document within the schools collection.

Configuration

  • Document Path: schools/{documentId}
    • This specifies the path to the Firestore documents in the schools collection that will trigger the function when written to.
  • Timeout: 180 seconds
    • The function has a longer execution timeout to handle potentially large or complex operations.

Operation

The mirrorSchools function uses the generateMirrorDocFunction to create a specific instance tailored for the schools collection. Here’s how it functions:

  1. Listening to Document Changes: The function listens for any write operations (including deletions) on the schools collection.
  2. Handling Changes:
    • If a document in the schools collection is deleted (snapshot.after.data() is null), the corresponding document in the mirrored collection is also deleted.
    • If a document is created or updated, the new data from snapshot.after.data() is used to update or create the document in the mirrored collection using the same document ID.

Example Execution Flow

  • Document Created/Updated: When a school document is created or updated, the function ensures that its data is replicated in another specified collection for assessment or administrative purposes.
  • Document Deleted: If a school document is deleted, the function also deletes the corresponding document in the mirrored collection to maintain data consistency.

Helper Function: generateMirrorDocFunction

  • Purpose: Dynamically generates a function configured to handle document write events and mirror these changes to a specified collection.
  • Usage in mirrorSchools:
    • The generated function from generateMirrorDocFunction("schools") specifically handles the mirroring of the schools collection documents.

Error Handling and Security

  • Error Handling: Implements checks for null data and handles database operations with try/catch blocks to manage exceptions gracefully.
  • Security Considerations:
    • Permissions: Ensure that the function has appropriate Firestore permissions to perform read and write operations on the schools collection and its mirror.
    • Data Validation: While primarily handled by Firebase rules, additional validation can be implemented within the function to prevent corrupt or invalid data mirroring.

Deployment and Maintenance

  • Deployment: This function should be deployed using Firebase CLI tools or through the Firebase Console, ensuring all configurations and dependencies are correctly set.
  • Maintenance: Regular monitoring and logging are recommended to track function performance and to quickly address any issues with data mirroring or function execution.