elasticbone

Connect Backbone to Elasticsearch

npm install elasticbone
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Elasticbone

NOTE: This project is still in development, and not production ready. Though hopefully soon it will be.

Elasticsearch is an awesome document store, with a nice rest api. Backbone is an awesome MVC framework, where the model are defined to interact with a rest api. Elasticbone is an extension making it easy for Backbone models to be connected to Elasticsearch documents.

Elasticbone is (should be) usable in both a browser, or node.js server.

To install

npm install elasticbone

Examples

The easiest way to describe elasticbone is to give a few examples based on creating a blog.

Elasticbone = require 'elasticbone'

class User extends Elasticbone.ElasticModel

class Post extends Elasticbone.ElasticModel

class Posts extends Elasticbone.ElasticCollection
  model: Post

Elasticmodels and elasticcollections reference an elasticsearch server, index and type.

The default type is the name of the model, in the case of a collection there is no default type.

class User extends Elasticbone.ElasticModel
  server: 'localhost:9000' 
  index: 'blog'

class Post extends Elasticbone.ElasticModel
  server: 'localhost:9000' 
  index: 'blog'

class Posts extends Elasticbone.ElasticCollection
  server: 'localhost:9000' 
  index: 'blog'
  type: 'Post'
  model: Post

Relationships

Elasticbone also lets you define relationships between backbone models and elasticsearch documents.

To relate models together the has function (inspired by rails) is used, and options are passed to it. The basic structure is has 'attribute', Model, {options}

By default the relationship will be treated as a subdocument, e.g.

Given a Post document in elasticsearch looks like:

{
tags: [{name: 'foo'}, {name: 'bar'}]
}

This relationships would be defined using elasticbone as such,

class Tag extends Backbone.Model

class Tags extends Backbone.Collection

class Post extends Elasticbone.ElasticModel
  ...
  @has 'tags', Tags

NOTE: Tag is not an ElasticModel as it is not a document in Elasticsearch.

has seperate ElasticModel relationship

class Posts extends Elasticbone.ElasticCollection
  fetch_query: -> {"query":{"field": {"author":"\"#{this.get('user').name}\""}}}

class User extends Elasticbone.ElasticModel
  ...
  @has 'posts', Posts, method: 'fetch'

user = new User(id: 1)
$.when(user.fetch()).done( (user) -> user.get('posts'))

Since fetching the posts is expencive Elasticbone will delay it until a get is called to retreive them. This uses jquery promises, so that you can register when a callback is fired. When user.get('posts') a promise is returned for the posts that are fetched out of elasticsearch using the fetch_query. This query returns all posts where the field author is exactly the users name.

Note: Circular has

A problem occurs when a model wants to have reverse relations, e.g. a user has posts, and a post has a user.

As javascript will execute in order THIS CODE WILL NOT WORK, because when User references posts it will not exist yet.

class User extends Elasticbone.ElasticModel
  @has 'posts', Posts

class Posts extends Elasticbone.ElasticCollection
  @has 'author', User

Instead you can use has after the classes declaration

class User extends Elasticbone.ElasticModel

class Posts extends Elasticbone.ElasticCollection
  @has 'author', User

User.has 'posts', Posts

GeoRegion & GeoJSON

A supported feature of elasticsearch is its GeoJSON querying with GeoQuery.find_intersecting

class Photo extends Elasticbone.ElasticModel
  ...
  @has 'location', Elasticbone.GeoShape

class Photos extends Elasticbone.ElasticCollection
  model: Photo

class GeoRegion extends Elasticbone.ElasticModel
  ...
  @has 'geo_shape', Elasticbone.GeoShape

class GeoRegions extends Elasticbone.ElasticCollection
  model: GeoRegion

Something like this will (should) work

#Box around new zealand
gr = new GeoRegion({'geo_shape' : { "type": "Polygon", "coordinates": [ [ [ 166.0, -47.6 ], [166.0, -34.3 ], [179.1, -34.3], [179.1, -47.6] ] ] } }, {parse: true})

#Search for all Photos in New Zealand
$.when(gr.get('geo_shape'))
.then((gs) -> GeoQuery.find_intersecting(gs, Photos, 'location'))
.done((photos) -> console.log "Photos from New Zealand", photos)

Development

Installation: npm inst Testing: npm test

Contribution: Welcome

Production release

Aimed support for

  1. has_one parse and fetch queries
  2. has_many parse and fetch queries
  3. Geographic Queries
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