Merge pull request sunspot#177 from wildoats/master

Adding support for range facets

README.md

@@ -387,6 +387,15 @@ search.facet(:average_rating).rows.each do |facet|
 end
 ```
 
+#### Range Facets
+
+```ruby
+# Posts faceted by range of average ratings
+Sunspot.search(Post) do
+  facet :average_rating, :range => 1..5, :range_interval => 1
+end
+```
+
 ### Ordering
 
 By default, Sunspot orders results by "score": the Solr-determined

sunspot/lib/sunspot/dsl/field_query.rb

@@ -185,6 +185,19 @@ def group(*field_names, &block)
       # semantic meaning is attached to them. The label for +facet+ should be
       # a symbol; the label for +row+ can be whatever you'd like.
       #
+      # ==== Range Facets
+      #
+      # One can use the Range Faceting feature on any date field or any numeric
+      # field that supports range queries. This is particularly useful for the
+      # cases in the past where one might stitch together a series of range
+      # queries (as facet by query) for things like prices, etc.
+      #
+      # For example faceting over average ratings can be done as follows:
+      #
+      #   Sunspot.search(Post) do
+      #     facet :average_rating, :range => 1..5, :range_interval => 1
+      #   end
+      #
       # ==== Parameters
       #
       # field_names...<Symbol>:: fields for which to return field facets
@@ -278,6 +291,15 @@ def facet(*field_names, &block)
                 end
                 search_facet = @search.add_date_facet(field, options)
                 Sunspot::Query::DateFieldFacet.new(field, options)
+              elsif options[:range]
+                unless [Sunspot::Type::TimeType, Sunspot::Type::FloatType, Sunspot::Type::IntegerType ].inject(false){|res,type| res || field.type.is_a?(type)}
+                  raise(
+                    ArgumentError,
+                    ':range can only be specified for date or numeric fields'
+                  )
+                end
+                search_facet = @search.add_range_facet(field, options)
+                Sunspot::Query::RangeFacet.new(field, options)
               else
                 search_facet = @search.add_field_facet(field, options)
                 Sunspot::Query::FieldFacet.new(field, options)

sunspot/lib/sunspot/query.rb

@@ -1,4 +1,4 @@
-%w(filter abstract_field_facet connective boost_query date_field_facet dismax
+%w(filter abstract_field_facet connective boost_query date_field_facet range_facet dismax
    field_facet highlighting pagination restriction common_query
    standard_query more_like_this more_like_this_query geo geofilt bbox query_facet
    scope sort sort_composite text_field_boost function_query

sunspot/lib/sunspot/query/range_facet.rb

@@ -0,0 +1,14 @@
+module Sunspot
+  module Query
+    class RangeFacet < AbstractFieldFacet
+      def to_params
+        params = super
+        params[:"facet.range"] = [@field.indexed_name]
+        params[qualified_param('range.start')] = @field.to_indexed(@options[:range].first)
+        params[qualified_param('range.end')] = @field.to_indexed(@options[:range].last)
+        params[qualified_param('range.gap')] = "#{@options[:range_interval] || 10}"
+        params
+      end
+    end
+  end
+end

sunspot/lib/sunspot/search.rb

@@ -1,5 +1,5 @@
 %w(abstract_search standard_search more_like_this_search query_facet field_facet
-   date_facet facet_row hit highlight field_group group hit_enumerable).each do |file|
+   date_facet range_facet facet_row hit highlight field_group group hit_enumerable).each do |file|
   require File.join(File.dirname(__FILE__), 'search', file)
 end
 

sunspot/lib/sunspot/search/abstract_search.rb

@@ -226,6 +226,11 @@ def add_date_facet(field, options) #:nodoc:
         add_facet(name, DateFacet.new(field, self, options))
       end
 
+      def add_range_facet(field, options) #:nodoc:
+        name = (options[:name] || field.name)
+        add_facet(name, RangeFacet.new(field, self, options))
+      end
+
       def highlights_for(doc) #:nodoc:
         if @solr_result['highlighting']
           @solr_result['highlighting'][doc['id']]

sunspot/lib/sunspot/search/range_facet.rb

@@ -0,0 +1,37 @@
+module Sunspot
+  module Search
+    class RangeFacet
+      def initialize(field, search, options)
+        @field, @search, @options = field, search, options
+      end
+
+      def field_name
+        @field.name
+      end
+
+      def rows
+        @rows ||=
+          begin
+            data = @search.facet_response['facet_ranges'][@field.indexed_name]
+            gap = (@options[:range_interval] || 10).to_i
+            rows = []
+
+            if data['counts']
+              Hash[*data['counts']].each_pair do |start_str, count|
+                start = start_str.to_f
+                finish = start + gap
+                rows << FacetRow.new(start..finish, count, self)
+              end
+            end
+
+            if @options[:sort] == :count
+              rows.sort! { |lrow, rrow| rrow.count <=> lrow.count }
+            else
+              rows.sort! { |lrow, rrow| lrow.value.first <=> rrow.value.first }
+            end
+            rows
+          end
+      end
+    end
+  end
+end

sunspot/spec/api/query/faceting_examples.rb

@@ -262,6 +262,58 @@
     end
   end
 
+  describe 'on range facets' do
+    before :each do
+      @range = 2..4
+    end
+
+    it 'does not send range facet parameters if integer range is not specified' do
+      search do |query|
+        query.facet :average_rating
+      end
+      connection.should_not have_last_search_with(:"facet.range")
+    end
+
+    it 'sets the facet to a range facet if the range is specified' do
+      search do |query|
+        query.facet :average_rating, :range => @range
+      end
+      connection.should have_last_search_with(:"facet.range" => ['average_rating_ft'])
+    end
+
+    it 'sets the facet start and end' do
+      search do |query|
+        query.facet :average_rating, :range => @range
+      end
+      connection.should have_last_search_with(
+        :"f.average_rating_ft.facet.range.start" => '2.0',
+        :"f.average_rating_ft.facet.range.end" => '4.0'
+      )
+    end
+
+    it 'defaults the range interval to 10' do
+      search do |query|
+        query.facet :average_rating, :range => @range
+      end
+      connection.should have_last_search_with(:"f.average_rating_ft.facet.range.gap" => "10")
+    end
+
+    it 'uses custom range interval' do
+      search do |query|
+        query.facet :average_rating, :range => @range, :range_interval => 1
+      end
+      connection.should have_last_search_with(:"f.average_rating_ft.facet.range.gap" => "1")
+    end
+
+    it 'does not allow date faceting on a non-continuous field' do
+      lambda do
+        search do |query|
+          query.facet :title, :range => @range
+        end
+      end.should raise_error(ArgumentError)
+    end
+  end
+
   describe 'using queries' do
     it 'turns faceting on' do
       search do