Connection Object

The Connection object represents a bidirectional relationship between users in the Replyke social features framework. Unlike follows, connections require mutual agreement between two users and represent equal partnerships similar to Facebook friends or LinkedIn connections.

Properties

Status Definitions

Characteristics

Bidirectional Relationship

• Mutual Agreement: Requires approval from both parties
• Equal Partnership: Once accepted, both users have equal status
• Request/Response Workflow: Structured approval process
• Complete History: Maintains full interaction history

Business Rules

1. Single Model Approach: One model handles requests and established connections
2. Duplicate Prevention: Only one active connection between any two users
3. Re-request Logic: After decline, only receiver can initiate new requests
4. Status Transitions: Clear progression from pending → accepted/declined

User Model Associations

The Connection model creates two associations with the User model:

// User hasMany Connection as "sentConnections" (as requester)
User.hasMany(Connection, {
  foreignKey: "requesterId",
  as: "sentConnections",
  onDelete: "CASCADE"
});
 
// User hasMany Connection as "receivedConnections" (as receiver)
User.hasMany(Connection, {
  foreignKey: "receiverId",
  as: "receivedConnections",
  onDelete: "CASCADE"
});

API Endpoints

User-Centric Operations

• POST /users/:userId/connection - Send connection request to user
• GET /users/:userId/connection - Get connection status with user
• DELETE /users/:userId/connection - Decline/withdraw/disconnect with user
• GET /users/:userId/connections - Get connections of specific user
• GET /users/:userId/connections-count - Get connections count for specific user

Connection-Centric Operations

• GET /connections - List established connections
• GET /connections/count - Get connections count
• GET /connections/pending/sent - List sent pending requests
• GET /connections/pending/received - List received pending requests
• PUT /connections/:connectionId/accept - Accept specific connection
• PUT /connections/:connectionId/decline - Decline specific connection
• DELETE /connections/:connectionId - Remove specific connection

Status Transitions

Valid Transitions

pending → accepted (by receiver)
pending → declined (by receiver)
pending → [DELETED] (by requester - withdraw)
accepted → [DELETED] (by either - disconnect)
declined → [DELETED] (by receiver only - to allow re-request)

Invalid Transitions

• declined → accepted (must delete and create new request)
• Cannot change status once responded (except delete for disconnect/re-request)

Usage Examples

Sending Connection Request

POST /users/user-123/connection
Body: { "message": "Hi! I'd like to connect." }
→ Creates Connection with status="pending", requesterId=current-user, receiverId=user-123

Accepting Connection

PUT /connections/connection-uuid/accept
→ Updates status to "accepted", sets respondedAt timestamp

Checking Connection Status

GET /users/user-123/connection
→ Returns detailed status: none/pending/connected/declined with metadata

Notification Strategy

Query Patterns

Get User’s Connections (Bidirectional)

-- User is connected if they are requester OR receiver with accepted status
SELECT * FROM Connections
WHERE projectId = ?
  AND status = 'accepted'
  AND (requesterId = ? OR receiverId = ?)

Get Pending Requests

-- Received requests
SELECT * FROM Connections
WHERE projectId = ? AND receiverId = ? AND status = 'pending'
 
-- Sent requests
SELECT * FROM Connections
WHERE projectId = ? AND requesterId = ? AND status = 'pending'

Performance Considerations

• Indexes: Optimized for queries by requesterId, receiverId, status, and projectId
• Pagination: All list endpoints support pagination
• Rate Limiting: Connection requests limited to 25 requests per 5 minutes
• Caching: Consider caching connection counts and lists for active users

Related Models

• User: The users involved in the connection relationship
• Follow: One-way relationship alternative that doesn’t require approval
• AppNotification: Notifications for connection requests and acceptances