NativeScript · DickSmith · Nov 12, 2017 · Nov 13, 2017 · Nov 13, 2017 · Nov 19, 2017
diff --git a/tns-core-modules/timer/timer.ios.ts b/tns-core-modules/timer/timer.ios.ts
@@ -25,7 +25,11 @@ class TimerTargetImpl extends NSObject {
 
     public tick(timer): void {
         if (!this.disposed) {
-            this.callback();
+            try {
+                this.callback();
+            } catch (e) {
+                // TODO
+            }
         }
 
         if (!this.shouldRepeat) {

diff --git a/tns-core-modules/ui/frame/frame-common.ts b/tns-core-modules/ui/frame/frame-common.ts
@@ -45,7 +45,7 @@ export function reloadPage(): void {
             create: currentEntry.create,
             moduleName: currentEntry.moduleName,
             backstackVisible: currentEntry.backstackVisible
-        }
+        };
 
         frame.navigate(newEntry);
     }
@@ -72,7 +72,7 @@ const moduleCreatePage = profile("module.createPage", (moduleNamePath: string, m
     if (traceEnabled()) {
         traceWrite("Calling createPage()", traceCategories.Navigation);
     }
-    var page = moduleExports.createPage();
+    const page = moduleExports.createPage();
 
     let cssFileName = resolveFileName(moduleNamePath, "css");
     // If there is no cssFile only appCss will be applied at loaded.
@@ -204,7 +204,7 @@ export class FrameBase extends CustomLayoutView implements FrameDefinition {
         const navigationContext: NavigationContext = {
             entry: backstackEntry,
             isBackNavigation: true
-        }
+        };
 
         this._navigationQueue.push(navigationContext);
 
@@ -273,7 +273,7 @@ export class FrameBase extends CustomLayoutView implements FrameDefinition {
         const navigationContext: NavigationContext = {
             entry: backstackEntry,
             isBackNavigation: false
-        }
+        };
 
         this._navigationQueue.push(navigationContext);
 
@@ -367,34 +367,38 @@ export class FrameBase extends CustomLayoutView implements FrameDefinition {
 
     @profile
     private performNavigation(navigationContext: NavigationContext) {
-        let navContext = navigationContext.entry;
+        if (navigationContext) {
+            let navContext = navigationContext.entry;
+
+            // TODO: This should happen once navigation is completed.
+            if (navContext && navContext.entry && navContext.entry.clearHistory) {
+                // Don't clear backstack immediately or we can't remove pages from frame.
+            } else if (FrameBase._isEntryBackstackVisible(this._currentEntry)) {
+                this._backStack.push(this._currentEntry);
+            }
 
-        // TODO: This should happen once navigation is completed.
-        if (navigationContext.entry.entry.clearHistory) {
-            // Don't clear backstack immediately or we can't remove pages from frame.
-        } else if (FrameBase._isEntryBackstackVisible(this._currentEntry)) {
-            this._backStack.push(this._currentEntry);
+            this._onNavigatingTo(navContext, navigationContext.isBackNavigation);
+            this._navigateCore(navContext);
         }
-
-        this._onNavigatingTo(navContext, navigationContext.isBackNavigation);
-        this._navigateCore(navContext);
     }
 
     @profile
     private performGoBack(navigationContext: NavigationContext) {
-        let backstackEntry = navigationContext.entry;
-        if (!backstackEntry) {
-            backstackEntry = this._backStack.pop();
-            navigationContext.entry = backstackEntry;
-        } else {
-            const index = this._backStack.indexOf(backstackEntry);
-            const removed = this._backStack.splice(index + 1);
-            this._backStack.pop();
-            this._removeBackstackEntries(removed);
+        if (navigationContext) {
+            let backstackEntry = navigationContext.entry;
+            if (!backstackEntry) {
+                backstackEntry = this._backStack.pop();
+                navigationContext.entry = backstackEntry;
+            } else {
+                const index = this._backStack.indexOf(backstackEntry);
+                const removed = this._backStack.splice(index + 1);
+                this._backStack.pop();
+                this._removeBackstackEntries(removed);
+            }
+
+            this._onNavigatingTo(backstackEntry, true);
+            this._goBackCore(backstackEntry);
         }
-
-        this._onNavigatingTo(backstackEntry, true);
-        this._goBackCore(backstackEntry);
     }
 
     public _goBackCore(backstackEntry: BackstackEntry) {
@@ -414,7 +418,9 @@ export class FrameBase extends CustomLayoutView implements FrameDefinition {
             this.currentPage.onNavigatingFrom(isBack);
         }
 
-        backstackEntry.resolvedPage.onNavigatingTo(backstackEntry.entry.context, isBack, backstackEntry.entry.bindingContext);
+        if (backstackEntry && backstackEntry.resolvedPage) {
+            backstackEntry.resolvedPage.onNavigatingTo(backstackEntry.entry.context, isBack, backstackEntry.entry.bindingContext);
+        }
     }
 
     public get animated(): boolean {

diff --git a/tns-core-modules/ui/frame/frame.android.ts b/tns-core-modules/ui/frame/frame.android.ts
@@ -168,34 +168,39 @@ export class Frame extends FrameBase {
         }
 
         transaction.replace(this.containerViewId, newFragment, newFragmentTag);
-        transaction.commit();
+        transaction.commitAllowingStateLoss();
     }
 
     public _goBackCore(backstackEntry: BackstackEntry) {
         super._goBackCore(backstackEntry);
-        navDepth = backstackEntry.navDepth;
 
-        const activity = this._android.activity;
-        const manager = activity.getFragmentManager();
-        const transaction = manager.beginTransaction();
+        if (backstackEntry) {
+            navDepth = backstackEntry.navDepth;
 
-        if (!backstackEntry.fragment) {
-            // Happens on newer API levels. On older all fragments
-            // are recreated once activity is created.
-            // This entry fragment was destroyed by app suspend.
-            // We need to recreate its animations and then reverse it.
-            backstackEntry.fragment = this.createFragment(backstackEntry, backstackEntry.fragmentTag);
-            _updateTransitions(backstackEntry);
-        }
+            const activity = this._android.activity;
+            if (activity) {
+                const manager = activity.getFragmentManager();
+                const transaction = manager.beginTransaction();
+
+                if (!backstackEntry.fragment) {
+                    // Happens on newer API levels. On older all fragments
+                    // are recreated once activity is created.
+                    // This entry fragment was destroyed by app suspend.
+                    // We need to recreate its animations and then reverse it.
+                    backstackEntry.fragment = this.createFragment(backstackEntry, backstackEntry.fragmentTag);
+                    _updateTransitions(backstackEntry);
+                }
 
-        const transitionReversed = _reverseTransitions(backstackEntry, this._currentEntry);
-        if (!transitionReversed) {
-            // If transition were not reversed then use animations.
-            transaction.setCustomAnimations(AnimationType.popEnterFakeResourceId, AnimationType.popExitFakeResourceId, AnimationType.enterFakeResourceId, AnimationType.exitFakeResourceId);
-        }
+                const transitionReversed = _reverseTransitions(backstackEntry, this._currentEntry);
+                if (!transitionReversed) {
+                    // If transition were not reversed then use animations.
+                    transaction.setCustomAnimations(AnimationType.popEnterFakeResourceId, AnimationType.popExitFakeResourceId, AnimationType.enterFakeResourceId, AnimationType.exitFakeResourceId);
+                }
 
-        transaction.replace(this.containerViewId, backstackEntry.fragment, backstackEntry.fragmentTag);
-        transaction.commit();
+                transaction.replace(this.containerViewId, backstackEntry.fragment, backstackEntry.fragmentTag);
+                transaction.commitAllowingStateLoss();
+            }
+        }
     }
 
     public _removeBackstackEntries(removed: BackstackEntry[]): void {