mahen3d / redis-eventemitter

Redis pubsub using an event emitter for node.js

redis-eventemitter

Use redis as pubsub using a simple eventemitter.

npm install redis-eventemitter

Usage

var redis = require('redis-eventemitter');

var pubsub = redis({
	prefix: 'production:',
	url: 'redis://myuser:mypass@localhost:6379/'
	// port: 6379,
	// host: '127.0.0.1',
	// auth_pass: '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:'[email protected]' });

API

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

var redis = require('redis-eventemitter');
var pubsub = redis({ prefix: 'production:', host: 'localhost', port: 6379 });

pubsub.emit('myservice:newuser', { id:'a1b2c3' });

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

var redis = require('redis-eventemitter');
var pubsub = redis({ scope: 'production:', host: 'localhost', port: 6379 });

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.

host

Host for the redis server.

url

Url for the redis server.

auth_pass

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

Redis client instance used for publish.

sub

Redis client instance used for subscribe.