Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP

A rich Ruby API and DSL for the ElasticSearch search engine/database

Fetching latest commit…

Cannot retrieve the latest commit at this time

README.markdown

Slingshot

Slingshot

Slingshot aims to provide a rich Ruby API and DSL for the ElasticSearch search engine/database.

ElasticSearch is a scalable, distributed, highly-available, RESTful database communicating by JSON over HTTP, based on Lucene, written in Java. It manages to very simple and very powerful at the same time. You should seriously consider it to power search in your Ruby applications: it will deliver all the features you want — and many more you may have not imagined yet (native geo search? histogram facets?)

Slingshot currently allow basic operation with the index and searching. See chapters below.

Installation

First, you need a running ElasticSearch server. Thankfully, it's easy. Let's define easy:

$ curl -L -o elasticsearch-0.14.4.tar.gz http://github.com/downloads/elasticsearch/elasticsearch/elasticsearch-0.14.4.tar.gz
$ tar -zxvf elasticsearch-0.14.4.tar.gz
$ ./elasticsearch-0.14.4/bin/elasticsearch -f

OK, easy. Now, install the gem via Rubygems:

$ gem install slingshot-rb

or from source:

$ git clone git://github.com/karmi/slingshot.git
$ rake install

Usage

Currently, you can use Slingshot via the DSL (eg. by extending your class with it). Plans for full ActiveModel integration (and other convenience layers) are in progress.

To kick the tiers, require the gem in an IRB session or a Ruby script (note that you can run the full example from examples/dsl.rb):

require 'rubygems'
require 'slingshot'

First, let's create an index named articles and store/index some documents:

Slingshot.index 'articles' do
  delete
  create

  store :title => 'One',   :tags => ['ruby']
  store :title => 'Two',   :tags => ['ruby', 'python']
  store :title => 'Three', :tags => ['java']
  store :title => 'Four',  :tags => ['ruby', 'php']

  refresh
end

Now, let's query the database:

We are searching for articles tagged ruby, sorted by title in descending order, and also retrieving some facets from the database:

s = Slingshot.search 'articles' do
  query do
    terms :tags, ['ruby']
  end

  sort do
    title 'desc'
  end

  facet 'global-tags' do
    terms :tags, :global => true
  end

  facet 'current-tags' do
    terms :tags
  end
end

Let's display the results:

s.results.each do |document|
  puts "* #{ document.title }"
end

# * Two
# * One
# * Four

Let's display the facets (distribution of tags across the whole database):

s.results.facets['global-tags']['terms'].each do |f|
  puts "#{f['term'].ljust(10)} #{f['count']}"
end

# ruby       3
# python     1
# php        1
# java       1

We can display the full query JSON:

puts s.to_json
# {"facets":{"current-tags":{"terms":{"field":"tags"}},"global-tags":{"global":true,"terms":{"field":"tags"}}},"sort":[{"title":"desc"}],"query":{"terms":{"tags":["ruby"]}}}

See, a Ruby DSL for this thing is kinda handy? We can query ElasticSearch manually with curl, simply:

puts s.to_curl
# curl -X POST "http://localhost:9200/articles/_search?pretty=true" -d '{"facets":{"current-tags":{"terms":{"field":"tags"}},"global-tags":{"global":true,"terms":{"field":"tags"}}},"sort":[{"title":"desc"}],"query":{"terms":{"tags":["ruby"]}}}'

Features

Currently, Slingshot supports only a limited subset of vast ElasticSearch Search API and it's Query DSL:

  • Creating, deleting and refreshing the index
  • Storing a document in the index
  • Querying the index with the query_string, term and terms types of queries
  • Sorting the results by fields
  • Retrieving a terms type of facets -- other types are high priority
  • Returning just specific fields from documents
  • Paging with from and size query options

See the examples/dsl.rb.

Todo & Plans

In order of importance:

Feedback

You can send feedback via e-mail or via Github Issues.


Karel Minarik

Something went wrong with that request. Please try again.