fix: Page and Frame isLoaded undefined checks (#6255)

Alexander Vakrilov · dtopuzov · commit 4a11cf907cfc · 2018-09-13T16:51:49.000+03:00
* fix(view): isLoaded handling closes #6179 * refactor: Error handling code in onCreateView
diff --git a/tns-core-modules/ui/core/view-base/view-base.ts b/tns-core-modules/ui/core/view-base/view-base.ts
@@ -595,13 +595,13 @@ export abstract class ViewBase extends Observable implements ViewBaseDefinition
     }
 
     public loadView(view: ViewBase): void {
-        if (!view.isLoaded) {
+        if (view && !view.isLoaded) {
             view.callLoaded();
         }
     }
 
     public unloadView(view: ViewBase): void {
-        if (view.isLoaded) {
+        if (view && view.isLoaded) {
             view.callUnloaded();
         }
     }
diff --git a/tns-core-modules/ui/core/view/view.android.ts b/tns-core-modules/ui/core/view/view.android.ts
@@ -185,7 +185,7 @@ function initializeDialogFragment() {
             }
 
             const owner = this.owner;
-            if (!owner.isLoaded) {
+            if (owner && !owner.isLoaded) {
                 owner.callLoaded();
             }
 
@@ -201,7 +201,7 @@ function initializeDialogFragment() {
             }
 
             const owner = this.owner;
-            if (owner.isLoaded) {
+            if (owner && owner.isLoaded) {
                 owner.callUnloaded();
             }
         }
diff --git a/tns-core-modules/ui/frame/frame.android.ts b/tns-core-modules/ui/frame/frame.android.ts
@@ -9,7 +9,7 @@ import { Page } from "../page";
 import * as application from "../../application";
 import {
     FrameBase, stack, goBack, View, Observable,
-    traceEnabled, traceWrite, traceCategories
+    traceEnabled, traceWrite, traceCategories, traceError
 } from "./frame-common";
 
 import {
@@ -720,8 +720,23 @@ class FragmentCallbacksImplementation implements AndroidFragmentCallbacks {
         }
 
         const entry = this.entry;
+        if (!entry) {
+            traceError(`${fragment}.onCreateView: entry is null or undefined`);
+            return null;
+        }
+
         const page = entry.resolvedPage;
+        if (!page) {
+            traceError(`${fragment}.onCreateView: entry has no resolvedPage`);
+            return null;
+        }
+
         const frame = this.frame;
+        if (!frame) {
+            traceError(`${fragment}.onCreateView: this.frame is null or undefined`);
+            return null;
+        }
+
         if (page.parent === frame) {
             // If we are navigating to a page that was destroyed
             // reinitialize its UI.
@@ -730,12 +745,12 @@ class FragmentCallbacksImplementation implements AndroidFragmentCallbacks {
                 page._setupUI(context);
             }
         } else {
-            if (!this.frame._styleScope) {
+            if (!frame._styleScope) {
                 // Make sure page will have styleScope even if parents don't.
                 page._updateStyleScope();
             }
 
-            this.frame._addView(page);
+            frame._addView(page);
         }
 
         if (frame.isLoaded && !page.isLoaded) {
diff --git a/tns-core-modules/ui/styling/style-scope.ts b/tns-core-modules/ui/styling/style-scope.ts
@@ -328,7 +328,7 @@ export class CssState {
      * As a result, at some point in time, the selectors matched have to be requerried from the style scope and applied to the view.
      */
     public onChange(): void {
-        if (this.view.isLoaded) {
+        if (this.view && this.view.isLoaded) {
             this.unsubscribeFromDynamicUpdates();
             this.updateMatch();
             this.subscribeForDynamicUpdates();

Original file line number	Diff line number	Diff line change
`@@ -595,13 +595,13 @@ export abstract class ViewBase extends Observable implements ViewBaseDefinition`
`595`	`595`	`}`
`596`	`596`
`597`	`597`	`public loadView(view: ViewBase): void {`
`598`		`- if (!view.isLoaded) {`
	`598`	`+ if (view && !view.isLoaded) {`
`599`	`599`	`view.callLoaded();`
`600`	`600`	`}`
`601`	`601`	`}`
`602`	`602`
`603`	`603`	`public unloadView(view: ViewBase): void {`
`604`		`- if (view.isLoaded) {`
	`604`	`+ if (view && view.isLoaded) {`
`605`	`605`	`view.callUnloaded();`
`606`	`606`	`}`
`607`	`607`	`}`
Original file line number	Diff line number	Diff line change
`@@ -185,7 +185,7 @@ function initializeDialogFragment() {`
`185`	`185`	`}`
`186`	`186`
`187`	`187`	`const owner = this.owner;`
`188`		`- if (!owner.isLoaded) {`
	`188`	`+ if (owner && !owner.isLoaded) {`
`189`	`189`	`owner.callLoaded();`
`190`	`190`	`}`
`191`	`191`
`@@ -201,7 +201,7 @@ function initializeDialogFragment() {`
`201`	`201`	`}`
`202`	`202`
`203`	`203`	`const owner = this.owner;`
`204`		`- if (owner.isLoaded) {`
	`204`	`+ if (owner && owner.isLoaded) {`
`205`	`205`	`owner.callUnloaded();`
`206`	`206`	`}`
`207`	`207`	`}`