suggestions.rb

module Suggestions
  def self.included( base )
    base.extend ClassMethods
  end
  
  module ClassMethods
    # USAGE:
    #
    # class Doctor
    #   # this model should have the typical Sunspot.setup clause somewhere else
    # 
    #   include Suggestions
    # end
    # 
    # Doctor.suggestions "John Smith D"
    #-
    def suggestions( keywords )
      prefix, full_words = prefix_and_full_words_from( keywords )
      
      Sunspot.search(Post) do |query|
        query.keywords(full_words, :fields => all_text_fields)
        text_fields do |text_fields_query|
          text_fields_query.any_of do |any_of_query|
            all_text_fields.each do |text_field|
              any_of_query.with(text_field).starting_with(prefix)
            end
          end
        end
      end
    end
    
    private
      def all_text_fields
        Sunspot::Setup.for(self).all_text_fields.collect(&:name)
      end
      
      def prefix_and_full_words_from( keywords )
        words = keywords.split(/\s+/)
        return words.pop, words.join(' ')
      end
  end
end