Rework to ensure views are named after the controller method name

app/controllers/api/traces_controller.rb

@@ -16,14 +16,9 @@ module Api
     around_action :api_call_handle_error
 
     def show
-      trace = Trace.visible.find(params[:id])
+      @trace = Trace.visible.find(params[:id])
 
-      if trace.public? || trace.user == current_user
-        @traces = [trace]
-        render "trace"
-      else
-        head :forbidden
-      end
+      head :forbidden unless @trace.public? || @trace.user == current_user
     end
 
     def update

app/controllers/api/users_controller.rb

@@ -38,7 +38,7 @@ module Api
 
     def gpx_files
       @traces = current_user.traces.reload
-      render "api/traces/trace", :content_type => "application/xml"
+      render :content_type => "application/xml"
     end
 
     private

app/views/api/traces/show.builder

@@ -0,0 +1,5 @@
+xml.instruct! :xml, :version => "1.0"
+
+xml.osm(OSM::API.new.xml_root_attributes) do |osm|
+  osm << render(@trace)
+end

app/views/api/users/gpx_files.builder

@@ -1,9 +1,7 @@
 xml.instruct! :xml, :version => "1.0"
 
-# basic attributes
-
 xml.osm(OSM::API.new.xml_root_attributes) do |osm|
   @traces.each do |trace|
-    osm << render(:partial => "api/traces/trace.builder", :locals => { :trace => trace })
+    osm << render(:partial => "api/traces/trace", :locals => { :trace => trace })
   end
 end