Refined the facet code, with thanks to Dan Pickett's fork, and added …

…drilling down within a facet set

README

@@ -103,3 +103,4 @@ Since I first released this library, there's been quite a few people who have su
 - Lachie Cox
 - Lourens Naude
 - Tom Davies
+- Dan Pickett

README.textile

@@ -103,3 +103,4 @@ Since I first released this library, there's been quite a few people who have su
 * Lachie Cox
 * Lourens Naude
 * Tom Davies
+* Dan Pickett

features/facets.feature

@@ -1,7 +1,26 @@
 Feature: Search and browse models by their defined facets
 
-  Scenario: Test
+  Scenario: Requesting facets
     Given Sphinx is running
     And I am searching on developers
     When I am requesting facet results
-    Then I should see facet results
+    Then I should have valid facet results
+    And I should have 4 facets
+    And I should have the facet State
+    And I should have the facet Country
+    And I should have the facet Age
+    And I should have the facet City
+
+  Scenario: Requesting facet results
+    Given Sphinx is running
+    And I am searching on developers
+    When I am requesting facet results
+    And I drill down where Country is Australia
+    Then I should get 11 results
+
+  Scenario: Requesting facet results by multiple facets
+    Given Sphinx is running
+    And I am searching on developers
+    When I am requesting facet results
+    And I drill down where Country is Australia and Age is 30
+    Then I should get 4 results

features/step_definitions/facet_steps.rb

@@ -2,7 +2,29 @@
   @method = :facets
 end
 
-Then "I should see facet results" do
+When /^I drill down where (\w+) is (\w+)$/ do |facet, value|
+  @results = results.for(facet.downcase.to_sym => value)
+end
+
+When /^I drill down where (\w+) is (\w+) and (\w+) is (\w+)$/ do |facet_one, value_one, facet_two, value_two|
+  value_one = value_one.to_i unless value_one[/^\d+$/].nil?
+  value_two = value_two.to_i unless value_two[/^\d+$/].nil?
+
+  @results = results.for(
+    facet_one.downcase.to_sym => value_one,
+    facet_two.downcase.to_sym => value_two
+  )
+end
+
+Then "I should have valid facet results" do
   results.should be_kind_of(Hash)
   results.values.each { |value| value.should be_kind_of(Hash) }
-end
+end
+
+Then /^I should have (\d+) facets?$/ do |count|
+  results.keys.length.should == count.to_i
+end
+
+Then /^I should have the facet (\w+)$/ do |name|
+  results[name.downcase.to_sym].should be_kind_of(Hash)
+end

features/support/models/developer.rb

@@ -3,5 +3,6 @@ class Developer < ActiveRecord::Base
     indexes country,  :facet => true
     indexes state,    :facet => true
     has age,          :facet => true
+    facet city
   end
 end

lib/thinking_sphinx.rb

@@ -13,6 +13,7 @@
 require 'thinking_sphinx/collection'
 require 'thinking_sphinx/configuration'
 require 'thinking_sphinx/facet'
+require 'thinking_sphinx/facet_collection'
 require 'thinking_sphinx/field'
 require 'thinking_sphinx/index'
 require 'thinking_sphinx/rails_additions'

lib/thinking_sphinx/attribute.rb

@@ -152,7 +152,7 @@ def type
     def to_facet
       return nil unless @faceted
 
-      ThinkingSphinx::Facet.new(unique_name, @columns, self)
+      ThinkingSphinx::Facet.new(self)
     end
 
     private

lib/thinking_sphinx/collection.rb

@@ -130,5 +130,13 @@ def each_with_weighting(&block)
         yield self[index], match[:weight]
       end
     end
+
+    def inject_with_groupby_and_count(initial = nil, &block)
+      index = -1
+      results[:matches].inject(initial) do |memo, match|
+        index += 1
+        yield memo, self[index], match[:attributes]["@groupby"], match[:attributes]["@count"]
+      end
+    end
   end
-end
+end

lib/thinking_sphinx/facet.rb

@@ -1,11 +1,17 @@
 module ThinkingSphinx
   class Facet
-    attr_reader :name, :column, :reference
+    attr_reader :reference
 
-    def initialize(name, columns, reference)
-      @name = name
-      @columns = columns
+    def initialize(reference)
       @reference = reference
+
+      if reference.columns.length != 1
+        raise "Can't translate Facets on multiple-column field or attribute"
+      end
+    end
+
+    def name
+      reference.unique_name
     end
 
     def attribute_name
@@ -32,18 +38,21 @@ def value(object, attribute_value)
       end
     end
 
+    def to_s
+      name
+    end
+
     private
 
     def translate(object, attribute_value)
-      if @columns.length > 1
-        raise "Can't translate Facets on multiple-column field or attribute"
-      end
-
-      column  = @columns.first
       column.__stack.each { |method|
         object = object.send(method)
       }
       object.send(column.__name)
     end
+
+    def column
+      @reference.columns.first
+    end
   end
 end

lib/thinking_sphinx/facet_collection.rb

@@ -0,0 +1,44 @@
+module ThinkingSphinx
+  class FacetCollection < Hash
+    attr_accessor :arguments
+
+    def initialize(arguments)
+      @arguments        = arguments.clone
+      @attribute_values = {}
+      @facets           = []
+    end
+
+    def add_from_results(facet, results)
+      self[facet.name]              = {}
+      @attribute_values[facet.name] = {}
+      @facets << facet
+
+      results.each_with_groupby_and_count { |result, group, count|
+        facet_value = facet.value(result, group)
+
+        self[facet.name][facet_value]               = count
+        @attribute_values[facet.name][facet_value]  = group
+      }
+    end
+
+    def for(hash = {})
+      arguments        = @arguments.clone
+      options          = arguments.extract_options!
+      options[:with] ||= {}
+
+      hash.each do |key, value|
+        attrib = facet_for_key(key).attribute_name
+        options[:with][attrib] = @attribute_values[key][value]
+      end
+
+      arguments << options
+      ThinkingSphinx::Search.search *arguments
+    end
+
+    private
+
+    def facet_for_key(key)
+      @facets.detect { |facet| facet.name == key }
+    end
+  end
+end

lib/thinking_sphinx/field.rb

@@ -115,7 +115,7 @@ def unique_name
     def to_facet
       return nil unless @faceted
 
-      ThinkingSphinx::Facet.new(unique_name, @columns, self)
+      ThinkingSphinx::Facet.new(self)
     end
 
     private

lib/thinking_sphinx/index/builder.rb

@@ -147,6 +147,15 @@ def has(*args)
         end
         alias_method :attribute, :has
 
+        def facet(*args)
+          options = args.extract_options!
+          options[:facet] = true
+
+          args.each do |columns|
+            attributes << Attribute.new(FauxColumn.coerce(columns), options)
+          end
+        end
+
         # Use this method to add some manual SQL conditions for your index
         # request. You can pass in as many strings as you like, they'll get
         # joined together with ANDs later on.

lib/thinking_sphinx/search.rb

@@ -21,7 +21,7 @@ def search_for_ids(*args)
 
         options = args.extract_options!
         page    = options[:page] ? options[:page].to_i : 1
-
+        
         ThinkingSphinx::Collection.ids_from_results(results, page, client.limit, options)
       end
 
@@ -353,18 +353,13 @@ def search_for_id(*args)
       end
 
       def facets(*args)
-        options = args.extract_options!.merge! :group_function => :attr
+        hash    = ThinkingSphinx::FacetCollection.new args
+        options = args.extract_options!.clone.merge! :group_function => :attr
 
-        options[:class].sphinx_facets.inject({}) do |hash, facet|
-          facet_result = {}
+        options[:class].sphinx_facets.inject(hash) do |hash, facet|
           options[:group_by] = facet.attribute_name
 
-          results = search *(args + [options])
-          results.each_with_groupby_and_count do |result, group, count|
-            facet_result[facet.value(result, group)] = count
-          end
-          hash[facet.name] = facet_result
-
+          hash.add_from_results facet, search(*(args + [options]))
           hash
         end
       end