Fix sorting embedded objects and single fields.

lib/active_admin/mongoid/document.rb

@@ -115,7 +115,12 @@ def columns_hash
 
     def reorder sorting
       return unscoped if sorting.blank?
-      options = sorting.split(' ')
+      if sorting.match /\".*\".*/
+        options = sorting.split(/ |\./)
+        options.shift if options.count == 3
+      else
+        options = sorting.split(' ')
+      end
       field, order = *options
       unscoped.order_by(field => order)
     end

lib/active_admin/mongoid/helpers/collection.rb

@@ -6,7 +6,11 @@ module Collection
       original_collection_size = instance_method(:collection_size)
       def collection_size(collection=collection)
         if(not collection.empty? and collection.first.class.included_modules.include?(Mongoid::Document))
-          collection.count(true)
+          if collection.first.class.embedded?
+            collection.count
+          else
+            collection.count(true)
+          end
         else
           original_collection_size(collection)
         end

spec/features/smoke_spec.rb

@@ -217,6 +217,46 @@
         click_on 'Posts'
       end
 
+      describe 'sorting' do
+        let!(:post) { Post.create!(title: "First Post", body: 'First Post', view_count: 5, admin_user: admin_user, other_user: other_user) }
+
+        it 'sorts by title' do
+          click_on 'Posts'
+          page.find('#index_table_posts > thead > tr > th > a', text: 'Title').click
+          page.first('#index_table_posts > tbody > tr').should have_content 'Quick Brown Fox'
+
+          page.find('#index_table_posts > thead > tr > th > a', text: 'Title').click
+          page.first('#index_table_posts > tbody > tr').should have_content 'First Post'
+        end
+
+        context 'with an embedded document' do
+          before do
+            Post.where(body: 'The quick brown fox jumps over the lazy dog.').update_all(author: { name: 'Bob', city: { name: 'Washington' } })
+            post.author = Author.new name: 'Adam', city: { name: 'California' }
+            post.save!
+            Post.all.each{|p| p.author.city }
+          end
+
+          it 'sorts by the embedded document field' do
+            click_on 'Posts'
+            visit '/admin/posts?order=author.name_desc'
+            page.first('#index_table_posts > tbody > tr').should have_content 'Bob'
+
+            visit '/admin/posts?order=author.name_asc'
+            page.first('#index_table_posts > tbody > tr').should have_content 'Adam'
+          end
+
+          it 'sorts by embedded document fields of the the embedded document' do
+            click_on 'Posts'
+            visit '/admin/posts?order=author.city.name_desc'
+            page.first('#index_table_posts > tbody > tr').should have_content 'Washington'
+
+            visit '/admin/posts?order=author.city.name_asc'
+            page.first('#index_table_posts > tbody > tr').should have_content 'California'
+          end
+        end
+      end
+
       describe "paginator" do
         it "must have paginator with 4 pages" do
           page.should have_css('.pagination > .page.current')
@@ -244,7 +284,5 @@
         end
       end
     end # context 'with 100 posts'
-
   end
-
 end

test_app/app/admin/posts.rb

@@ -8,4 +8,35 @@
   filter :admin_user, as: :select
   filter :other_user, as: :check_boxes
 
+  index do
+    selectable_column
+    column :title
+    column :body
+    column :view_count
+    column 'Author Name', :'author.name' do |post|
+      post.author.name if post.author.present?
+    end
+    column 'Author City Name', :'author.city.name' do |post|
+      author = post.author
+      author.city.name if author.present? and author.city.present?
+    end
+    default_actions
+  end
+
+  show do
+    attributes_table do
+      row :title
+      row :body
+      row :created_at
+      row :updated_at
+    end
+  end
+
+  form do |f|
+    f.inputs "Post" do
+      f.input :title
+      f.input :body
+    end
+    f.actions
+  end
 end

test_app/app/models/author.rb

@@ -0,0 +1,9 @@
+class Author
+  include Mongoid::Document
+  include Mongoid::Timestamps
+
+  embedded_in :post
+  embeds_one :city
+
+  field :name
+end

test_app/app/models/city.rb

@@ -0,0 +1,7 @@
+class City
+  include Mongoid::Document
+  include Mongoid::Timestamps
+
+  embedded_in :author
+  field :name
+end

test_app/app/models/post.rb

@@ -7,4 +7,7 @@ class Post
   field :view_count, type: ::Integer, default: 0
   belongs_to :admin_user
   belongs_to :other_user, class_name: 'AdminUser'
+
+  embeds_one :author
+  field :'author.city.name'
 end