From 12e5f6c1162adc1094026c5539932a66f5767fb9 Mon Sep 17 00:00:00 2001
From: Andy Joslin <andytjoslin@gmail.com>
Date: Tue, 29 Apr 2014 06:09:34 -0600
Subject: [PATCH] fix(ionView): only $watch attributes if defined

Closes #1216
---
 js/angular/directive/view.js | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/js/angular/directive/view.js b/js/angular/directive/view.js
index 7721c54b4ea..bf39433556f 100644
--- a/js/angular/directive/view.js
+++ b/js/angular/directive/view.js
@@ -59,15 +59,19 @@ IonicModule
 
         }
 
-        $scope.$watch($attr.hideBackButton, function(value) {
-          // Should we hide a back button when this tab is shown
-          navBarCtrl.showBackButton(!value);
-        });
+        if (angular.isDefined($attr.hideBackButton)) {
+          $scope.$watch($attr.hideBackButton, function(value) {
+            // Should we hide a back button when this tab is shown
+            navBarCtrl.showBackButton(!value);
+          });
+        }
 
-        $scope.$watch($attr.hideNavBar, function(value) {
-          // Should the nav bar be hidden for this view or not?
-          navBarCtrl.showBar(!value);
-        });
+        if (angular.isDefined($attr.hideNavBar)) {
+          $scope.$watch($attr.hideNavBar, function(value) {
+            // Should the nav bar be hidden for this view or not?
+            navBarCtrl.showBar(!value);
+          });
+        }
 
       };
     }