Version 3 proposal: Add a :sort_by option

As indicated in #29, the currently undocumented behavior of a
direct call to `ranked_in_list` is to do no sorting on the results.
The call was originally intended to be used to retrieve a list
of friends from a leaderboard. However, it would be useful in
certain situations to have the results sorted. This adds a
`:sort_by` option to that would be appropriate for the
`ranked_in_list` call to sort by either score (`:score`) or
rank (`:rank`) when returning results.

lib/leaderboard.rb

@@ -32,12 +32,14 @@ class Leaderboard
   # +:with_member_data+ false: Return member data along with the member names.
   # +:use_zero_index_for_rank+ false: If you want to 0-index ranks.
   # +:page_size+ nil: The default page size will be used.
+  # +:sort_by+ :none: The default sort for a call to `ranked_in_list`.
   DEFAULT_LEADERBOARD_REQUEST_OPTIONS = {
     :with_scores => true,
     :with_rank => true,
     :with_member_data => false,
     :use_zero_index_for_rank => false,
-    :page_size => nil
+    :page_size => nil,
+    :sort_by => :none
   }
 
   # Name of the leaderboard.
@@ -835,6 +837,13 @@ def ranked_in_list_in(leaderboard_name, members, options = {})
       ranks_for_members << data
     end
 
+    case leaderboard_options[:sort_by]
+    when :rank
+      ranks_for_members = ranks_for_members.sort_by { |member| member[:rank] }
+    when :score
+      ranks_for_members = ranks_for_members.sort_by { |member| member[:score] }
+    end
+
     ranks_for_members
   end
 

spec/leaderboard_spec.rb

@@ -638,4 +638,40 @@
     members[0][:score].to_i.should be(25)
     members[24][:member].should eql('member_1')
   end
+
+  it 'should sort by rank if the :sort_by option is set to :rank' do
+    rank_members_in_leaderboard(25)
+
+    members = ['member_5', 'member_1', 'member_10']
+    ranked_members = @leaderboard.ranked_in_list(members, :sort_by => :rank)
+
+    ranked_members.size.should be(3)
+
+    ranked_members[0][:rank].should be(16)
+    ranked_members[0][:score].should eql(10.0)
+
+    ranked_members[1][:rank].should be(21)
+    ranked_members[1][:score].should eql(5.0)
+
+    ranked_members[2][:rank].should be(25)
+    ranked_members[2][:score].should eql(1.0)
+  end
+
+  it 'should sort by score if the :sort_by option is set to :score' do
+    rank_members_in_leaderboard(25)
+
+    members = ['member_5', 'member_1', 'member_10']
+    ranked_members = @leaderboard.ranked_in_list(members, :sort_by => :score)
+
+    ranked_members.size.should be(3)
+
+    ranked_members[0][:rank].should be(25)
+    ranked_members[0][:score].should eql(1.0)
+
+    ranked_members[1][:rank].should be(21)
+    ranked_members[1][:score].should eql(5.0)
+
+    ranked_members[2][:rank].should be(16)
+    ranked_members[2][:score].should eql(10.0)
+  end
 end

spec/reverse_leaderboard_spec.rb

@@ -354,4 +354,40 @@
     members[0][:score].to_i.should be(1)    
     members[24][:member].should eql('member_25')
   end
+
+  it 'should sort by rank if the :sort_by option is set to :rank' do
+    rank_members_in_leaderboard(25)
+
+    members = ['member_5', 'member_1', 'member_10']
+    ranked_members = @leaderboard.ranked_in_list(members, :sort_by => :rank)
+
+    ranked_members.size.should be(3)
+
+    ranked_members[0][:rank].should be(1)
+    ranked_members[0][:score].should eql(1.0)
+
+    ranked_members[1][:rank].should be(5)
+    ranked_members[1][:score].should eql(5.0)
+
+    ranked_members[2][:rank].should be(10)
+    ranked_members[2][:score].should eql(10.0)
+  end
+
+  it 'should sort by score if the :sort_by option is set to :score' do
+    rank_members_in_leaderboard(25)
+
+    members = ['member_5', 'member_1', 'member_10']
+    ranked_members = @leaderboard.ranked_in_list(members, :sort_by => :score)
+
+    ranked_members.size.should be(3)
+
+    ranked_members[0][:rank].should be(1)
+    ranked_members[0][:score].should eql(1.0)
+
+    ranked_members[1][:rank].should be(5)
+    ranked_members[1][:score].should eql(5.0)
+
+    ranked_members[2][:rank].should be(10)
+    ranked_members[2][:score].should eql(10.0)
+  end
 end