ioredis-eventemitter

Redis pubsub using an event emitter via ioredis Redis client

ioredis is a robust, performance-focused and full-featured Redis client for Node and io.js.

This work based on redis-eventemitter

Install

    npm install ioredis-eventemitter

Usage

pub/sub clients must be compatible ioredis

var redis = require('ioredis-eventemitter');
 
var pubsub = redis({
    port: 6379,
    host: '127.0.0.1',
    prefix: 'production:',
    password: 'mypassword'
    // in case you want to control Redis clients
    // creation you can specify pub/sub clients pair:
    // pub: pubClient,
    // sub: subClient
});
 
// Listen for messages on the *:newuser channel
pubsub.on('*:newuser', function(channel, user) {
    console.log(channel); // prints "myservice:newuser"
    console.log(user);    // user is a json map as expected
});
 
// Publish an event "production:myservice:newuser" to the redis pubsub
pubsub.emit('myservice:newuser', { id:'a1b2c3', email:'[e-mail]' });

API

.emit(channel, messages...) [publish]

var redis = require('ioredis-eventemitter');
var pubsub = redis({ prefix: 'production:' });
 
pubsub.emit('myservice:newuser', { id:'a1b2c3' });

.on(pattern, function(channel, messages...) { ... }) [subscribe]

var redis = require('ioredis-eventemitter');
var pubsub = redis({ prefix:'production:' });
 
pubsub.on('*:newuser', function(channel, message) {
    console.log(channel); // myservice:newuser
    console.log(message); // { id:'a1b2c3' }
});

.on('error', function(err) { ... }) [error handling]

To be able to handle errors (like when the redis server is down) .on('error', ...) should be used.

Note that this means that you can't listen for messages on the error channel.

.removeListener(pattern, listener)

Removes listener.

.removeAllListeners(pattern)

Removes all listeners.

Options

port

Port for the redis server. Defaults to 6379.

host

Host for the redis server. Defaults to 127.0.0.1.

password

Password for the redis server. Defaults to not being set.

prefix

A prefix that is added to the channel name, when publishing events to the redis pubsub. Useful for separating services or environments, e.g. production, development, and staging.

It is also removed when the listeners is invoked.

pub

ioredis compatible Redis client instance used for publish.

sub

ioredis compatible Redis client instance used for subscribe.