Extensions to Backbone.js to support MongoDB use as a back-end data store.

Overview

Adds a Backbone.Sync implementation for working with MongoDB databases. Thus you can use Backbone models as usual, just needsa collectionName attribute in the Model definition that specifies the MongoDB collection to work with.

Moreover, it extends Backbone.Model and Backbone.Collection with some meaningful features. The general idea of extension was to provide the usual success/error callback handling of Backbone together with MongoDB integration.

1. Controllers have a find, findOne and _withCollection methods that allow you to query for many models, one model or do arbitrary operations on the related MongoDB collection, respectively.
2. Models can be set up easily to handle embedded and related documents, using a nestAs attribute in the model's definition.

These extra features are documented below.

Usage

Server side

Example:

var Db = require('backbone-mongodb/lib/db),
  db = new Db({
    name: 'test',
    host: '127.0.0.1',
    'port': 27017
    })
  db.on('connected', function(err){
    ...
    })

require('backbone-mongodb');
...
var MyCollection = Backbone.Collection.extend({
    collectionName: 'myCollection'
    })

collectionName can be specified for Model definitions too.

In the browser

Just include the backbone-mongodb.js file from the public folder.

API

Database access

The lib/db.js file specifies the database access and setup methods.

Example:

var Db = require('backbone-mongodb/lib/db),
  db = new Db({
    name: 'test',
    host: '127.0.0.1',
    port: 27017,
    autoconnect: true
    })
  db.on('connected', function(err){
    ...
    })

The returned database object supports events.

Exported methods are:

• open()
• close()
• getConnection()

Controller extensions

find method

The find method returns a new collection that satisfy the search criteria.

Signature: find(args, options)

• args: JSON object to be passed on to MongoDB's find
• options: either a JSON object with success/error callbacks, or a NodeJS callback function

findOne method

The findOne method returns a new Model instance associated with the given collection.

Signature: findOne(args, options)

• args: JSON object to be passed on to MongoDB's find
• options: either a JSON object with success/error callbacks, or a NodeJS callback function

_withCollection method

The withCollection method returns a reference to the related MongoDB collection. Thus arbitrary operations can be performed on the collection.

Signature: _withCollection(callback)

• callback: a usual NodeJS callback function

Model extensions

nested and embedded attribute

Using the nested and embedded attributes four types of nesting are possible. One can nest:

1. another model from a JSON argument (embed)
2. another collection from JSON array as an argument (embed)
3. another model from model & ID as an argument (nest)
4. another collection from list of IDs as an argument (nest)

Example:

var MyModel = Backbone.Model.extend({
      embedded: {
        case1: MyModel,
        case2: MyCollection,
      },
      nestAs: {
        case3: MyCollection,
        case4: MyCollection
      },
      defaults: {
        case4: []
      }
  }),
  MyCollection = Backbone.Collection.extend({
      model: MyModel
  });
var newModel = new MyModel({subdata: 'subvalue'});
myModel.save(null, {success: function(newModel){
    var mainModel = new MyModel({
        case1: {subdata: 'subvalue'},
        case2: newModel.id,
        case3: [{subdata: 'subvalue'}],
        case4: [newModel.id]
      })
    console.log(mainModel.case1);
    console.log(mainModel.case2);
    console.log(mainModel.case3);
    console.log(mainModel.case4);
    }})

As you can see in the example above

• all the cases give you the nested attribute as a direct attribute of the model, mainModel.attributeName;
• the first case requires you to give the resulting model, while the other cases require a collection;

The code in the background registers several event listeners to handle changes in values in both directions as much as possible.

TODO

• add support for save method bubbling

Credit

The original idea came from donedotcom.