Merge pull request sunspot#146 from alindeman/raphaelcm-field_grouping

Add support for additional grouping request parameters.

README.md

@@ -471,6 +471,16 @@ Post.search do
     order_by(:average_rating, :desc)
   end
 end
+
+# Facet count is based on the most relevant document of each group
+# matching the query (>= Solr 3.4)
+Post.search do
+  group :blog_id_str do
+    truncate
+  end
+
+  facet :blog_id_str, :extra => :any
+end
 ```
 
 ### Geospatial

sunspot/lib/sunspot/dsl/field_group.rb

@@ -13,6 +13,26 @@ def limit(num)
         @group.limit = num
       end
 
+      #
+      # If set, facet counts are based on the most relevant document of
+      # each group matching the query.
+      #
+      # Supported in Solr 3.4 and above.
+      #
+      # ==== Example
+      #
+      #     Sunspot.search(Post) do
+      #       group :title do
+      #         truncate
+      #       end
+      #
+      #       facet :title, :extra => :any
+      #     end
+      #
+      def truncate
+        @group.truncate = true
+      end
+
       # Specify the order that results should be returned in. This method can
       # be called multiple times; precedence will be in the order given.
       #

sunspot/lib/sunspot/query/field_group.rb

@@ -4,7 +4,7 @@ module Query
     # A FieldGroup groups by the unique values of a given field.
     #
     class FieldGroup
-      attr_accessor :limit
+      attr_accessor :limit, :truncate
 
       def initialize(field)
         if field.multiple?
@@ -27,6 +27,7 @@ def to_params
 
         params.merge!(@sort.to_params("group."))
         params[:"group.limit"] = @limit if @limit
+        params[:"group.truncate"] = @truncate if @truncate
 
         params
       end

sunspot/spec/integration/faceting_spec.rb

@@ -134,6 +134,19 @@ def self.test_field_type(name, attribute, field, *args)
       search.facet(:title).rows.first.value.should == :none
       search.facet(:title).rows.first.count.should == 1
     end
+
+    it 'gives correct facet count when group == true and truncate == true' do
+      search = Sunspot.search(Post) do
+        group :title do
+          truncate
+        end
+
+        facet :title, :extra => :any
+      end
+
+      # Should be 5 instead of 11
+      search.facet(:title).rows.first.count.should == 5
+    end
   end
 
   context 'multiselect faceting' do

sunspot/spec/integration/field_grouping_spec.rb

@@ -1,4 +1,5 @@
 require File.expand_path("../spec_helper", File.dirname(__FILE__))
+require File.expand_path("../helpers/search_helper", File.dirname(__FILE__))
 
 describe "field grouping" do
   before :each do