SocialDB

SocialDB is a Redis-backed social graph for Node.js. It uses a friend model similar to Facebook where two users have to follow each other to be friends.

All operations run as asynchronous atomic transactions, so the database is never left in an invalid state. All methods return native Promises. Redis is the ideal storage mechanism for friend relationships, since they can be stored as sets. With sets you can do interesting things with set intersection to find mutual friends, recommended friends, etc. SocialDB stores friend relationships as sorted sets ordered by date.

Installation

npm install socialdb

Run Redis server

Check out Redis quickstart to install for your platform, or use one of the many cloud providers.

A convenience script is provided for macOS default Homebrew Redis installs:

npm run redis

API

• follow(fromId, toId)
• unfollow(fromId, toId)
• invite(userId, someId)
• block(fromId, toId)
• requested(userId)
• pending(userId)
• accepted(userId)
• friends(userId) (alias of accepted())

Usage

Step 1: Initialize an instance of SocialDB

Require SocialDB:

const SocialDB = require('socialdb');

Initialize SocialDB, connecting to a Redis client:

const sd = new SocialDB(redisClient);

Step 2: Profit

Note: This example uses async/await, only available in Node 7.6+.

// user 2 requests to follow user 3
await sd.follow(2, 3)
console.log(await sd.requested(2)); 
// ['3']
console.log(await sd.pending(3)); 
// ['2']

// user 3 requests to follow user 2 back
await sd.follow(3, 2);
console.log(await sd.friends(2)); 
// ['3']
console.log(await sd.friends(3)); 
// ['2']

// user 2 requests to unfollow user 3
await sd.unfollow(2, 3);
console.log(await sd.friends(2)); 
// []
console.log(await sd.friends(3)); 
// []

// user 2 invites user with phone number +14153337777
await sd.invite(2, '+14153337777')
console.log(await sd.invited('+14153337777')); 
// [2]

Debugging

Add DEBUG=socialdb to your node start script to see debug output. i.e:

DEBUG=socialdb node server.js

Tests

npm install
npm test