add method 'last' to simplify queries

lib/couchrest/model/class_proxy.rb

@@ -75,6 +75,12 @@ module CouchRest
           doc
         end
         
+        def last(opts = {})
+          doc = @klass.last({:database => @database}.merge(opts))
+          doc.database = @database if doc && doc.respond_to?(:database)
+          doc
+        end
+        
         def get(id)
           doc = @klass.get(id, @database)
           doc.database = @database if doc && doc.respond_to?(:database)

lib/couchrest/model/document_queries.rb

@@ -38,6 +38,22 @@ module CouchRest
           first_instance.empty? ? nil : first_instance.first
         end
         
+        # Load the last document that have the model_type_key's field equal to
+        # the name of the current class.
+        # It's similar to method first, just adds :descending => true
+        #
+        # ==== Returns
+        # Object:: The last object instance available
+        # or
+        # Nil:: if no instances available
+        #
+        # ==== Parameters
+        # opts<Hash>::
+        # View options, see <tt>CouchRest::Database#view</tt> options for more info.
+        def last(opts = {})
+          first(opts.merge!(:descending => true))
+        end
+        
         # Load a document from the database by id
         # No exceptions will be raised if the document isn't found
         #

spec/couchrest/class_proxy_spec.rb

@@ -87,6 +87,12 @@ describe "Proxy Class" do
     u = @us.first
     u.title.should =~ /\A...\z/
   end
+  
+  it "should get last" do
+    u = @us.last
+    u.title.should == "aaa"
+  end
+  
   it "should set database on first retreived document" do
     u = @us.first
     u.database.should === DB

spec/couchrest/view_spec.rb

@@ -273,6 +273,12 @@ describe "Model views" do
       u = Unattached.first :database=>@db
       u.title.should =~ /\A...\z/
     end
+    
+    it "should get last" do
+      u = Unattached.last :database=>@db
+      u.title.should == "aaa"
+    end
+    
     it "should barf on all_design_doc_versions if no database given" do
       lambda{Unattached.all_design_doc_versions}.should raise_error
     end