Awesome
Elasticsearch::DSL
The elasticsearch-dsl
library provides a Ruby API for the Elasticsearch Query DSL.
Installation
Install the package from Rubygems:
gem install elasticsearch-dsl
To use an unreleased version, either add it to your Gemfile
for Bundler:
gem 'elasticsearch-dsl', git: 'git://github.com/elasticsearch/elasticsearch-dsl-ruby.git'
or install it from a source code checkout:
git clone https://github.com/elasticsearch/elasticsearch-dsl-ruby.git
cd elasticsearch-dsl-ruby
bundle install
rake install
Usage
The library is designed as a group of standalone Ruby modules, classes and DSL methods, which provide an idiomatic way to build complex search definitions.
Let's have a simple example using the declarative variant:
require 'elasticsearch/dsl'
include Elasticsearch::DSL
definition = search do
query do
match title: 'test'
end
end
definition.to_hash
# => { query: { match: { title: "test"} } }
require 'elasticsearch'
client = Elasticsearch::Client.new trace: true
client.search body: definition
# curl -X GET 'http://localhost:9200/test/_search?pretty' -d '{
# "query":{
# "match":{
# "title":"test"
# }
# }
# }'
# ...
# => {"took"=>10, "hits"=> {"total"=>42, "hits"=> [...] } }
Let's build the same definition in a more imperative fashion:
require 'elasticsearch/dsl'
include Elasticsearch::DSL
definition = Search::Search.new
definition.query = Search::Queries::Match.new title: 'test'
definition.to_hash
# => { query: { match: { title: "test"} } }
The library doesn't depend on an Elasticsearch client -- its sole purpose is to facilitate building search definitions in Ruby. This makes it possible to use it with any Elasticsearch client:
require 'elasticsearch/dsl'
include Elasticsearch::DSL
definition = search { query { match title: 'test' } }
require 'json'
require 'faraday'
client = Faraday.new(url: 'http://localhost:9200')
response = JSON.parse(
client.post(
'/_search',
JSON.dump(definition.to_hash),
{ 'Accept' => 'application/json', 'Content-Type' => 'application/json' }
).body
)
# => {"took"=>10, "hits"=> {"total"=>42, "hits"=> [...] } }
Features Overview
The library allows to programatically build complex search definitions for Elasticsearch in Ruby, which are translated to Hashes, and ultimately, JSON, the language of Elasticsearch.
All Elasticsearch DSL features are supported, namely:
- Queries and Filter context
- Aggregations
- Suggestions
- Sorting
- Pagination
- Options (source filtering, highlighting, etc)
Please see the extensive RDoc examples in the source code and the integration tests.
Accessing methods outside DSL blocks' scopes
Methods can be defined and called from within a block. This can be done for values like a Hash
,
String
, Array
, etc. For example:
def match_criteria
{ title: 'test' }
end
s = search do
query do
match match_criteria
end
end
s.to_hash
# => { query: { match: { title: 'test' } } }
To define subqueries in other methods, self
must be passed to the method and the subquery must be defined in a block
passed to instance_eval
called on the object argument. Otherwise, the subquery does not have access to the scope of
the block from which the method was called. For example:
def not_clause(obj)
obj.instance_eval do
_not do
term color: 'red'
end
end
end
s = search do
query do
filtered do
filter do
not_clause(self)
end
end
end
end
s.to_hash
# => { query: { filtered: { filter: { not: { term: { color: 'red' } } } } } }
Development
See CONTRIBUTING.