Change API

Architecture

The data-system allows your application to keep real-time state of the data through a pub-sub api. Redis is used as the pub-sub connecter.

API

The available channels are as follow :

Channel              Msg             Description
[docType].create     id      Fired when a doc of given docType is created
[docType].update     id      Fired when a doc of given docType is updated
[docType].delete     id      Fired when a doc of given docType is deleted through the data-system

null.create          id      Fired when a doc with no docType is created
null.update          id      Fired when a doc with no docType is updated
null.delete          id      Fired when a doc with no docType is deleted through the data-system

delete               id      Fired when a doc is deleted (even if not through the data-system)

NB : when a doc is deleted from the data-system, both docType.delete and delete are fired.

Usage

In your application, simply do : coffeescript redis = require('redis').createClient() redis.on 'pmessage', (pattern, event, id) -> #event = "doctype.operation" #id = document's id #pattern = [pattern] #see below redis.psubscribe '[pattern]'

[pattern] can use a wildcard * : for example *.create , note.*, *.

You can psubscribe to several patterns.

Example

Let's say we want to be informed of every note operation and task suppression

redis.on 'pmessage', (pattern, event, id) ->
   if pattern is 'note.*'
       if event is 'note.create'
          Note.find id, (err, note) ->
              # do stuff with note
   else if event is 'task.delete'
       # Task with id = id have been deleted

redis.psubscribe 'note.*'
redis.psubscribe 'task.delete'

You can also simply proxy to a socket.io server for real time client update

redis.on 'pmessage', (pattern, event, id) ->
   io.sockets.emit event, id
redis.psubscribe 'note.*'