Ajaxify the potential organizer selector

Finishes railsbridge#369

app/controllers/organizers_controller.rb

@@ -5,7 +5,14 @@ class OrganizersController < ApplicationController
 
   def index
     @organizer_rsvps = @event.organizer_rsvps
-    @users = User.not_assigned_as_organizer(@event)
+  end
+
+  def potential
+    respond_to do |format|
+      format.json do
+        render json: UserSearcher.new(User.not_assigned_as_organizer(@event), params[:q])
+      end
+    end
   end
 
   def create

app/services/user_searcher.rb

@@ -0,0 +1,24 @@
+class UserSearcher
+  def initialize(relation, query)
+    @relation = relation
+    @query = query
+  end
+
+  def as_json(options = {})
+    search_field = @relation.connection.concat('lower(first_name)', "' '", 'lower(last_name)')
+    @relation
+      .select(:id, :first_name, :last_name)
+      .where("#{search_field} like ?", "%#{@query.downcase}%")
+      .map { |u| {id: u.id, text: u.full_name} }
+  end
+
+  private
+
+  def db_concat(*fields)
+    if false
+      "CONCAT(#{fields.join(', ')})"
+    else
+      fields.join(' || ')
+    end
+  end
+end

app/views/organizers/index.html.erb

@@ -8,7 +8,8 @@
            action: event_organizers_path(@event),
            select_id: 'event_organizer',
            foreign_key: 'user_id',
-           choices: @users.collect {|u| [ u.full_name, u.id ] }
+           url: potential_event_organizers_path(@event),
+           choices: []
 %>
 
 <h3>Assigned Organizers</h3>

app/views/shared/_user_chooser.html.erb

@@ -7,7 +7,24 @@
                  {include_blank: ''},
                  class: 'form-control') %>
       <script>
-        $('#<%= select_id %>_<%= foreign_key %>').select2({minimumInputLength: 3, delay: 250})
+        var options = {};
+        <% if defined?(url) %>
+          _.extend(options, {
+            minimumInputLength: 3,
+            ajax: {
+              url: '<%= url %>',
+              dataType: 'json',
+              delay: 250,
+              processResults: function (data, page) {
+                return {
+                  results: data
+                };
+              },
+              cache: true
+            }
+          });
+        <% end %>
+        $('#<%= select_id %>_<%= foreign_key %>').select2(options);
       </script>
       <%= submit_tag "Assign", class: "btn btn-primary", style: 'margin: 10px 0;' %>
     <% end %>

config/initializers/activerecord_concat.rb

@@ -0,0 +1,16 @@
+# https://gist.github.com/eric1234/5622690
+module ActiveRecord
+  module ConnectionAdapters
+    class AbstractAdapter
+      def concat(*args)
+        args * " || "
+      end
+    end
+
+    class PostgreSQLAdapter < AbstractAdapter
+      def concat(*args)
+        "CONCAT(#{args * ', '})"
+      end
+    end
+  end
+end

config/routes.rb

@@ -18,7 +18,9 @@
   end
 
   resources :events do
-    resources :organizers, only: [:index, :create, :destroy]
+    resources :organizers, only: [:index, :create, :destroy] do
+      get :potential, on: :collection
+    end
     resources :checkiners, only: [:index, :create, :destroy]
     resources :volunteers, only: [:index]
 

spec/features/event_organizers_request_spec.rb

@@ -19,12 +19,14 @@
     page.should have_content("Sam Spade")
   end
 
-  it "allows an organizer to assign another user as an organizer" do
+  it "allows an organizer to assign another user as an organizer", js: true do
     visit "/events/#{@event.id}/organizers"
 
-    page.should have_select('event_organizer[user_id]', options: ['', @user1.full_name])
+    page.should have_select('event_organizer[user_id]')
 
-    select(@user1.full_name, :from =>'event_organizer_user_id')
+    page.find('.select2-selection').click
+    page.find('.select2-search__field').set(@user1.full_name)
+    page.find('.select2-results__option').click
 
     click_button "Assign"
 
@@ -44,14 +46,10 @@
       page.should have_content("user1@mail.com")
       page.should have_selector('input[value="Remove"]')
 
-      page.should have_select('event_organizer[user_id]', options: [''])
-
       click_button "Remove"
 
       page.should_not have_content("user1@mail.com")
       page.should_not have_selector('input[value="Remove"]')
-
-      page.should have_select('event_organizer[user_id]', options: ['', @user1.full_name])
     end
   end
 end

spec/services/user_searcher_spec.rb

@@ -0,0 +1,11 @@
+require 'rails_helper'
+
+describe UserSearcher do
+  let!(:user1) { create(:user, first_name: 'Abrahat', last_name: 'Zachson') }
+  let!(:user2) { create(:user, first_name: 'Rochalle', last_name: 'Gorfdoor') }
+
+  it 'returns the users matching a search query' do
+    searcher = UserSearcher.new(User, 'hat')
+    expect(searcher.as_json).to match_array([{id: user1.id, text: user1.full_name}])
+  end
+end