From 6b7d05420e1ca3c6b3e9f559b05cd0dc0711f5e7 Mon Sep 17 00:00:00 2001
From: Rossen Hristov <rossen.hristov@telerik.com>
Date: Thu, 4 Feb 2016 16:02:30 +0200
Subject: [PATCH] Resolved Issue #1021: The navigatedTo event is called twice
 for the first application page.

---
 apps/tests/app/mainPage.ts | 20 +++++++++-----------
 ui/frame/frame.ios.ts      | 14 ++++++++++++++
 2 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/apps/tests/app/mainPage.ts b/apps/tests/app/mainPage.ts
index f0d76ab97..8060aa485 100644
--- a/apps/tests/app/mainPage.ts
+++ b/apps/tests/app/mainPage.ts
@@ -5,20 +5,18 @@ import tests = require("../testRunner");
 trace.enable();
 trace.addCategories(trace.categories.Test + "," + trace.categories.Error);
 
-let started = false;
 let page = new Page();
 page.id = "mainPage";
 
-page.on(Page.navigatedToEvent, function () {
-    if (!started) {
-        started = true;
-        setTimeout(function () {
-            tests.runAll();
-        }, 10);
-    }
-});
+page.on(Page.navigatedToEvent, onNavigatedTo);
 
+function onNavigatedTo(args) {
+    args.object.off(Page.navigatedToEvent, onNavigatedTo);
+    setTimeout(function () {
+        tests.runAll();
+    }, 10);
+
+}
 export function createPage() {
     return page;
-}
-
+}
\ No newline at end of file
diff --git a/ui/frame/frame.ios.ts b/ui/frame/frame.ios.ts
index ce2a31a94..2ab52a4a7 100644
--- a/ui/frame/frame.ios.ts
+++ b/ui/frame/frame.ios.ts
@@ -356,6 +356,7 @@ class UINavigationControllerImpl extends UINavigationController implements UINav
     }
 
     public navigationControllerWillShowViewControllerAnimated(navigationController: UINavigationController, viewController: UIViewController, animated: boolean): void {
+        trace.write(`UINavigationControllerImpl.navigationControllerWillShowViewControllerAnimated(${navigationController}, ${viewController}, ${animated})`, trace.categories.NativeLifecycle);
         // In this method we need to layout the new page otherwise page will be shown empty and update after that which is bad UX.
         let frame = this._owner.get();
         if (!frame) {
@@ -381,9 +382,22 @@ class UINavigationControllerImpl extends UINavigationController implements UINav
         }
 
         newPage.actionBar.update();
+        
+        //HACK: https://github.com/NativeScript/NativeScript/issues/1021
+        viewController["willShowCalled"] = true;
     }
 
     public navigationControllerDidShowViewControllerAnimated(navigationController: UINavigationController, viewController: UIViewController, animated: boolean): void {
+        trace.write(`UINavigationControllerImpl.navigationControllerDidShowViewControllerAnimated(${navigationController}, ${viewController}, ${animated})`, trace.categories.NativeLifecycle);
+
+        //HACK: https://github.com/NativeScript/NativeScript/issues/1021
+        if (viewController["willShowCalled"] === undefined) {
+            return;
+        }
+        else {
+            viewController["willShowCalled"] = undefined;
+        }
+
         let frame = this._owner.get();
         if (!frame) {
             return;