[#3942] Added a controller to handle JavaScript requests for a CustomField options.

* Added OverheadTimeEntryActivityController which requires administrator access
* Added a partial which will render the HTML options for a select field
* Added some RSpec examples

app/controllers/overhead_time_entry_activity_controller.rb

@@ -0,0 +1,34 @@
+class OverheadTimeEntryActivityController < ApplicationController
+  unloadable
+
+  before_filter :require_admin
+  
+  def index
+    if params[:custom_field]
+      @field = TimeEntryActivityCustomField.find(params[:custom_field])
+      @values = select_values_for_field(@field)
+    end
+    @values ||= []
+    
+    render :partial => 'values'
+  end
+
+  private
+  
+  def select_values_for_field(field)
+    if field.field_format == 'list'
+      returning [] do |r|
+        field.possible_values.each do |item|
+          if item == 'Nil'
+            r << [l(:label_none), item] # Nil should use the none label
+          else
+            r << [item, item]
+          end
+        end
+        r
+      end
+    elsif field.field_format == 'bool'
+      return [[true,true],[false,false]]
+    end
+  end
+end

app/views/overhead_time_entry_activity/_values.html.erb

@@ -0,0 +1 @@
+<%= options_for_select(@values) %>