core/docs/follower.md

Following System

Overview

System supports following different entity types:

• Authors
• Topics
• Communities
• Shouts (Posts)

GraphQL API

Mutations

follow

Follow an entity (author/topic/community/shout).

Parameters:

• what: String! - Entity type (AUTHOR, TOPIC, COMMUNITY, SHOUT)
• slug: String - Entity slug
• entity_id: Int - Optional entity ID

Returns:

{
  authors?: Author[]        // For AUTHOR type
  topics?: Topic[]          // For TOPIC type
  communities?: Community[] // For COMMUNITY type
  shouts?: Shout[]          // For SHOUT type
  error?: String            // Error message if any
}

unfollow

Unfollow an entity.

Parameters: Same as follow

Returns: Same as follow

Queries

get_shout_followers

Get list of users who reacted to a shout.

Parameters:

• slug: String - Shout slug
• shout_id: Int - Optional shout ID

Returns:

Author[] // List of authors who reacted

Caching System

Supported Entity Types

• Authors: cache_author, get_cached_follower_authors
• Topics: cache_topic, get_cached_follower_topics
• Communities: No cache
• Shouts: No cache

Cache Flow

1. On follow/unfollow:
   • Update entity in cache
   • Update follower's following list
2. Cache is updated before notifications

Notifications

• Sent when author is followed/unfollowed
• Contains:
  • Follower info
  • Author ID
  • Action type ("follow"/"unfollow")

Error Handling

• Unauthorized access check
• Entity existence validation
• Duplicate follow prevention
• Full error logging
• Transaction safety with local_session()

Database Schema

Follower Tables

• AuthorFollower
• TopicFollower
• CommunityFollower
• ShoutReactionsFollower

Each table contains:

• follower - ID of following user
• {entity_type} - ID of followed entity