implemented nav_bar_button class method RE #272

app/test_screens/detail_screen.rb

@@ -1,3 +1,5 @@
 class DetailScreen < PM::Screen
   title "Detail"
+
+  nav_bar_button :right, title: "More", style: :plain, action: :back
 end

lib/ProMotion/screen/screen_module.rb

@@ -13,6 +13,7 @@ module ProMotion
       resolve_title
       apply_properties(args)
       add_nav_bar(args) if args[:nav_bar]
+      add_nav_bar_buttons
       tab_bar_setup
       try :screen_setup
       try :on_init
@@ -46,6 +47,10 @@ module ProMotion
       end
     end
 
+    def add_nav_bar_buttons
+      set_nav_bar_button(self.class.get_nav_bar_button[:side], self.class.get_nav_bar_button) if self.class.get_nav_bar_button
+    end
+
     def status_bar_hidden(hidden)
       UIApplication.sharedApplication.setStatusBarHidden(hidden, withAnimation:self.class.status_bar_animation)
     end
@@ -229,6 +234,15 @@ module ProMotion
       def status_bar_animation
         @status_bar_animation || UIStatusBarAnimationSlide
       end
+
+      def nav_bar_button(side, args={})
+        @nav_bar_button_args = args
+        @nav_bar_button_args[:side] = side
+      end
+
+      def get_nav_bar_button
+        @nav_bar_button_args
+      end
     end
 
     def self.included(base)

spec/unit/screen_helpers_spec.rb

@@ -88,6 +88,11 @@ describe "screen helpers" do
       end
 
     end
+
+    it "allows setting a nav_bar_button with a class method" do
+      screen = DetailScreen.new(nav_bar: true)
+      screen.navigationItem.rightBarButtonItem.class.should == UIBarButtonItem
+    end
   end
 
   describe "screen navigation" do