ElasticSearch Autocomplete

Quick and simple way to perform autocomplete with ElasticSearch Servers.

Installation

Add this line to your application's Gemfile:

gem 'elasticsearch-autocomplete'

And then execute:

$ bundle install

Dependencies

• Elasticsearch::Model
• Rails > 3.2.8
• Elasticsearch Server > 1.0.1

Usage

Field Explaination

Access each field as if they were a nested attribute (field.fuzzy, field.exact, ...).

Searching

map file (ROOT/lib/elasticsearch/autocomplete/TYPE_type.rb)

module Elasticsearch
  module Autocomplete
    class ColorType < Type
      # Value of ElasticSearch's _type
      # => String || Array
      def type
        'color'
      end

      # Search Hash
      # This is the entire search query for ElasticSearch
      #
      def to_hash
        {
          query: { match_all: {}},
          filter: {
            and: [
              { term: {_type: 'color'} }
            ]
          }
        }
      end

      # Return the hash to which the result is mapped from
      # @method mapped
      # @param source {OpenStruct} Source value from ElasticSearch result
      # @return Hash
      #
      def mapped(source)
        {
          id: source.id,
          name: source.name,
          image: image_path(source.icon),
          type: type
        }
      end

      # Optional to set
      # If you intend on using any of the helpers, this will need to be set
      #
      def field
        :name
      end
    end
  end
end

controller

# Search Multiple Types, each with their own query
search = Elasticsearch::Autocomplete::Search.find(index_string, params[:term], ['actress'])
search.results # => []

# Multiple Types, with a single result set
# @param index {String} ElasticSearch Index Name
# @param term {String} Query String being searched
# @param types {Array} Array of types being searched for in ElasticSearch
# @param multisearch {Boolean} Are we splitting each type into its own query?
# @param field {String|Symbol} If doing a single query, pass the name of the field to be searched
search = Elasticsearch::Autocomplete::Search.find(index_string, params[:term], ['actress'], false, :name)
search.results # => []

model indexing

# Assuming you are using Elasticsearch::Model as your indexing tool

mapping do
  # ...
  # Normal
  indexes :field_name, Elasticsearch::Autocomplete::Filters.config(:field_name)

  # Merge options to fields
  indexes :field_name, Elasticsearch::Autocomplete::Filters.config(:field_name, {options_here: :now})

  # .config returns as a hash, so you are able to merge there as well
  # ...
end

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake rspec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

Type Helper Methods

def image_path(image_string)
  # => Generates an asset url for an image
end

# https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-multi-match-query.html
# Quickly use the multiple fields matcher search format
# Usage: { query: multi_match({exact: 30}) }
#
def multi_match(rank_overrides={})
  ranks = {exact: 10, beginning: 7, autocomplete: 5, fuzzy: 1}.merge(rank_overrides)

  {..}
  # => returns built hash for the multi_match query
end

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Any contributions are welcome. As of right now, a lot of these settings are just set in stone. I'd like to eventually have more in-depth customizable options.

TODO

• Create generator for new types
• Change filters to a YAML Configuration
  • Create generator that provides default configuration