add autocomplete feature for Blacklight using Solr suggestor

app/assets/javascripts/blacklight/autocomplete.js

@@ -0,0 +1,31 @@
+/*global Bloodhound */
+
+Blacklight.onLoad(function() {
+  'use strict';
+
+  $('[data-autocomplete-enabled="true"]').each(function() {
+    var $el = $(this);
+    var suggestUrl = $el.data().autocompletePath;
+
+    var terms = new Bloodhound({
+      datumTokenizer: Bloodhound.tokenizers.obj.whitespace('value'),
+      queryTokenizer: Bloodhound.tokenizers.whitespace,
+      remote: {
+        url: suggestUrl + '?q=%QUERY'
+      }
+    });
+
+    terms.initialize();
+
+    $el.typeahead({
+      hint: true,
+      highlight: true,
+      minLength: 2
+    },
+    {
+      name: 'terms',
+      displayKey: 'term',
+      source: terms.ttAdapter()
+    });
+  });
+});

app/controllers/concerns/blacklight/suggest.rb

@@ -0,0 +1,15 @@
+module Blacklight
+  module Suggest
+    extend ActiveSupport::Concern
+    include Blacklight::Suggest::SuggestHelper
+
+    def index
+      @response = get_suggestions params
+      respond_to do |format|
+        format.json do
+          render json: @response.suggestions
+        end
+      end
+    end
+  end
+end

app/controllers/concerns/blacklight/suggest/suggest_helper.rb

@@ -0,0 +1,32 @@
+module Blacklight
+  module Suggest
+    module SuggestHelper
+      extend ActiveSupport::Concern
+      include Blacklight::SearchHelper
+
+      ##
+      # For now, only use the q parameter to create a
+      # Blacklight::Suggest::Response
+      # @param [Hash] params
+      # @return [Earthworks::Suggest::Response]
+      def get_suggestions(params)
+        request_params = { q: params[:q] }
+        Blacklight::Suggest::Response.new suggest_results(request_params), request_params, suggest_handler_path
+      end
+
+      ##
+      # Query the suggest handler using RSolr::Client::send_and_receive
+      # @param [Hash] request_params
+      # @return [RSolr::HashWithResponse]
+      def suggest_results(request_params)
+        repository.connection.send_and_receive(suggest_handler_path, params: request_params)
+      end
+
+      ##
+      # @param [String]
+      def suggest_handler_path
+        repository.blacklight_config.autocomplete_path
+      end
+    end
+  end
+end

app/controllers/suggest_controller.rb

@@ -0,0 +1,3 @@
+class SuggestController < ApplicationController
+  include Blacklight::Suggest
+end

app/helpers/blacklight/suggest_helper_behavior.rb

@@ -0,0 +1,10 @@
+module Blacklight
+  module SuggestHelperBehavior
+    ##
+    # @return [Boolean] should autocomplete be enabled in the UI
+    def autocomplete_enabled?
+      blacklight_config.autocomplete_enabled.present? &&
+        blacklight_config.autocomplete_path.present?
+    end
+  end
+end

app/helpers/suggest_helper.rb

@@ -0,0 +1,3 @@
+module SuggestHelper
+  include Blacklight::SuggestHelperBehavior
+end

app/models/concerns/blacklight/suggest/response.rb

@@ -0,0 +1,26 @@
+module Blacklight
+  module Suggest
+    class Response
+      attr_reader :response, :request_params, :suggest_path
+
+      ##
+      # Creates a suggest response
+      # @param [RSolr::HashWithResponse] response
+      # @param [Hash] request_params
+      # @param [String] suggest_path
+      def initialize(response, request_params, suggest_path)
+        @response = response
+        @request_params = request_params
+        @suggest_path = suggest_path
+      end
+
+      ##
+      # Trys the suggestor response to return suggestions if they are
+      # present
+      # @return [Array]
+      def suggestions
+        response.try(:[], suggest_path).try(:[], 'mySuggester').try(:[], request_params[:q]).try(:[], 'suggestions') || []
+      end
+    end
+  end
+end

app/views/catalog/_search_form.html.erb

@@ -11,7 +11,7 @@
     <% end %>
 
     <label for="q" class="sr-only"><%= t('blacklight.search.form.search.label') %></label>
-    <%= text_field_tag :q, params[:q], placeholder: t('blacklight.search.form.search.placeholder'), class: "search_q q form-control", id: "q", autofocus: should_autofocus_on_search_box?  %>
+    <%= text_field_tag :q, params[:q], placeholder: t('blacklight.search.form.search.placeholder'), class: "search_q q form-control", id: "q", autofocus: should_autofocus_on_search_box?, data: { autocomplete_enabled: autocomplete_enabled?, autocomplete_path: blacklight.suggest_index_path }  %>
 
     <span class="input-group-btn">
       <button type="submit" class="btn btn-primary search-btn" id="search">

config/routes.rb

@@ -6,4 +6,5 @@
   put "saved_searches/save/:id",    :to => "saved_searches#save",    :as => "save_search"
   delete "saved_searches/forget/:id",  :to => "saved_searches#forget",  :as => "forget_search"
   post "saved_searches/forget/:id",  :to => "saved_searches#forget"
+  resources :suggest, only: :index, defaults: { format: 'json' }
 end

lib/generators/blacklight/templates/catalog_controller.rb

@@ -180,6 +180,10 @@ class <%= controller_name.classify %>Controller < ApplicationController
     # If there are more than this many search results, no spelling ("did you 
     # mean") suggestion is offered.
     config.spell_max = 5
+
+    # Configuration for autocomplete suggestor
+    config.autocomplete_enabled = true
+    config.autocomplete_path = 'suggest'
   end
 
 end 

spec/controllers/blacklight/suggest/suggest_helper_spec.rb

@@ -0,0 +1,29 @@
+require 'spec_helper'
+
+describe Blacklight::Suggest::SuggestHelper do
+  let(:controller) { (Class.new(ApplicationController) { include Blacklight::Suggest::SuggestHelper }).new }
+  subject { controller}
+
+  let(:blacklight_config) { Blacklight::Configuration.new }
+  let(:blacklight_solr) { RSolr.connect(Blacklight.connection_config) }
+
+  before do
+    blacklight_config.autocomplete_path = 'suggest'
+  end
+
+  describe '#get_suggestions' do
+    it 'returns a Blacklight::Suggest::Response' do
+      expect(subject).to receive(:suggest_results).with(q: 'test')
+      expect(subject.get_suggestions q: 'test').to be_an Blacklight::Suggest::Response
+    end
+  end
+  describe '#suggest_results' do
+    it 'queries the suggest handler with params' do
+      allow(blacklight_solr).to receive(:get) do |path, params|
+        expect(path).to eq 'suggest'
+        expect(params).to eq params: { q: 'test' }
+      end
+      subject.suggest_results q: 'test'
+    end
+  end
+end

spec/controllers/suggest_controller_spec.rb

@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+describe SuggestController do
+  routes { Blacklight::Engine.routes }
+  describe 'GET index' do
+    it 'assigns @response' do
+      get :index, format: 'json'
+      expect(assigns(:response)).to be_an Blacklight::Suggest::Response
+    end
+    it 'returns JSON' do
+      get :index, format: 'json'
+      puts response.body
+      expect(response.body).to eq [].to_json
+    end
+    it 'returns suggestions' do
+      get :index, format: 'json', q: 'new'
+      json = JSON.parse(response.body)
+      expect(json.count).to eq 3
+      expect(json.first['term']).to eq 'new jersey'
+    end
+  end
+end

spec/helpers/suggest_helper_spec.rb

@@ -0,0 +1,41 @@
+require 'spec_helper'
+
+describe SuggestHelper do
+  before do
+    allow(helper).to receive(:blacklight_config).and_return(blacklight_config)
+  end
+  describe '#autocomplete_enabled?' do
+    describe 'with autocomplete config' do
+      let(:blacklight_config) do
+        Blacklight::Configuration.new.configure do |config|
+          config.autocomplete_enabled = true
+          config.autocomplete_path = 'suggest'
+        end
+      end
+      it 'is enabled' do
+        expect(helper.autocomplete_enabled?).to be true
+      end
+    end
+    describe 'without disabled config' do
+      let(:blacklight_config) do
+        Blacklight::Configuration.new.configure do |config|
+          config.autocomplete_enabled = false
+          config.autocomplete_path = 'suggest'
+        end
+      end
+      it 'is disabled' do
+        expect(helper.autocomplete_enabled?).to be false
+      end
+    end
+    describe 'without path config' do
+      let(:blacklight_config) do
+        Blacklight::Configuration.new.configure do |config|
+          config.autocomplete_enabled = true
+        end
+      end
+      it 'is disabled' do
+        expect(helper.autocomplete_enabled?).to be false
+      end
+    end
+  end
+end

spec/models/blacklight/suggest/response_spec.rb

@@ -0,0 +1,55 @@
+require 'spec_helper'
+
+describe Blacklight::Suggest::Response do
+  let(:empty_response) { described_class.new({}, { q: 'hello' }, 'suggest') }
+  let(:full_response) do
+    described_class.new(
+      {
+        'responseHeader' => {
+          'status' => 200
+        },
+        'suggest' => {
+          'mySuggester' => {
+            'new' => {
+              'numFound' => 3,
+              'suggestions' => [
+                {
+                  'term' => 'new jersey',
+                  'weight' => 3,
+                  'payload' => ''
+                },
+                {
+                  'term' => 'new jersey bridgeton biography',
+                  'weight' => 3,
+                  'payload' => ''
+                },
+                {
+                  'term' => 'new jersey bridgeton history',
+                  'weight' => 3,
+                  'payload' => ''
+                }
+              ]
+            }
+          }
+        }
+      },
+      {
+        q: 'new'
+      },
+      'suggest'
+    )
+  end
+
+  describe '#initialize' do
+    it 'creates a Blacklight::Suggest::Response' do
+      expect(empty_response).to be_an Blacklight::Suggest::Response
+    end
+  end
+  describe '#suggestions' do
+    it 'returns an array of suggestions' do
+      expect(full_response.suggestions).to be_an Array
+      expect(full_response.suggestions.count).to eq 3
+      expect(full_response.suggestions.first['term']).to eq 'new jersey'
+    end
+  end
+end