Save Post ID in User Model's Attribute posts Whenever a User Posts Something

[Alpha17-2]

Description

Implement functionality to save the post ID in the posts attribute of the user model whenever a user creates a new post. This ensures that each user maintains a list of their post IDs for easy reference and retrieval.

Requirements

1. Update User Model:

   • Ensure the user model includes an attribute posts, which is an array to store post IDs.

2. Save Post ID:

   • When a user creates a new post, the post ID should be added to the posts array of the user who created the post.

3. Firestore Structure:

   • User Document: { userId: string, posts: array of post IDs, ...other attributes }
   • Post Document: { postId: string, userId: string, ...other attributes }

Implementation Steps

1. Update User Model:

   • Modify the Firestore user document structure to include a posts array if not already present.

2. Create Post and Update User Document:

   • Implement functionality to create a new post document in Firestore.
   • After creating the post, retrieve the post ID.
   • Add the post ID to the posts array in the corresponding user document.

3. Ensure Atomicity:

   • Use Firestore transactions or batch writes to ensure that both the post creation and user document update occur atomically.