sithmel/backboneio.couchdbstorage

A storage middleware for couchdb and backbone.io

backboneio.couchdbstorage

A storage middleware for couchdb and backbone.io.

Syntax:

couchdbstorage(db)

It returns a backbone.io middleware that manages CRUD on a couchdb database

Example:

// import modules
var backboneio = require('backbone.io'),
    couchdbstorage = require('./couchdbstorage')couchdbstorage,
    nano = require('nano')('http://localhost:5984'); // define couchdb url
    
 
var backend = backboneio.createBackend(),  // create a backbone backend
    db = nano.use('dbname');  // define an existing couchdb database

// this is optional: I manually retrieve a view in case I don't want 
// to get all the documents

backend.read(function(req, res) {
    if (!req.model.id) {
        db.view("designname", "viewname", function (err, body){
            var out = []
            if (!err) {
                body.rows.forEach(function(doc) {
                    out.push(doc.value);
                });
                res.end(out);
            }
            else {
                console.log(err);
            }
        });        
    }
});

// couchdbstorage manage CRUD on db
backend.use(couchdbstorage(db));

Backbone configuration

Don't forget to set your id attribute to "_id":

MyModel = Backbone.Model.extend({
    idAttribute: "_id",
    ...

Setting up change feed

If you need to notify your clients for changes of different servers you can use the couchdb change feed:

var setupSync = require('./couchdbstorage').setupSync;

var feed = setupSync(db, backend);
feed.follow();

The library filters automatically changes coming from the current process.

You can notify backend events to a subset of clients using the channel feature of backbone.io. The channel is determined by a function that takes the model and get the channel.

var getChannel = function (model) {
    return model.group;
};


var feed = setupSync(db, backend, getChannel);
feed.follow();

Warning!! This doesn't work for deletion (just create/update).

To leverage this feature you must use an updated version that support:

backend.emit('updated', { id: 'myid', foo: 'baz' }, "mychannel");

You can find this information in the backbone.io README.md.