René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Error when using animated transition during navigation on Android 21 and 22","articleBody":"### Tell us about the problem\r\n\r\nAn error is thrown if using slide animation during navigation\r\n\r\n### Which platform(s) does your issue occur on?\r\n\r\nAndroid\r\n\r\n### Please provide the following version numbers that your issue occurs with:\r\n- CLI: 4.0.0\r\n- Cross-platform modules: 4.0.0\r\n- Runtime(s): 4.0.0\r\n- Plugin(s): N/A\r\n\r\n### Is there code involved? If so, please share the minimal amount of code needed to recreate the problem.\r\n\r\nCreate a new {N} application using CLI 4.0.0:\r\n\r\n```\r\ntns create my-app --tsc\r\n```\r\n\r\nOn the main page add a button with a tap event calling into a function that will navigate to a second page:\r\n\r\n```\r\npublic navigateToSecondPage(): void {\r\n    topmost().navigate({\r\n        moduleName: \"component/component-page\",\r\n        animated: true,\r\n        transition: {\r\n            name: \"slide\",\r\n            duration: 200,\r\n            curve: \"ease\"\r\n        }\r\n    });\r\n}\r\n```\r\n\r\nIn the second page view model constructor try to open some url (opening the url doesn't necessarily need to be done inside the constructor - the problem occurs also if this is done inside a click of a button):\r\n\r\n```\r\nimport { Observable } from \"tns-core-modules/data/observable\";\r\nimport { openUrl } from \"utils/utils\";\r\n\r\nexport class ComponentViewModel extends Observable {\r\n    constructor() {\r\n        super();\r\n        openUrl(\"https://www.google.com\");\r\n    }\r\n}\r\n```\r\n\r\nOn Android API levels 21 and 22, the following exception is thrown:\r\n\r\n```\r\nW/System.err(16021): java.lang.NullPointerException: Attempt to read from field 'int android.app.Fragment.mContainerId' on a null object reference\r\nW/System.err(16021):    at android.app.BackStackRecord$1.onPreDraw(BackStackRecord.java:1127)\r\nW/System.err(16021):    at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:847)\r\nW/System.err(16021):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1956)\r\nW/System.err(16021):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1054)\r\nW/System.err(16021):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5779)\r\nW/System.err(16021):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)\r\nW/System.err(16021):    at android.view.Choreographer.doCallbacks(Choreographer.java:580)\r\nW/System.err(16021):    at android.view.Choreographer.doFrame(Choreographer.java:550)\r\nW/System.err(16021):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)\r\nW/System.err(16021):    at android.os.Handler.handleCallback(Handler.java:739)\r\nW/System.err(16021):    at android.os.Handler.dispatchMessage(Handler.java:95)\r\nW/System.err(16021):    at android.os.Looper.loop(Looper.java:135)\r\nW/System.err(16021):    at android.app.ActivityThread.main(ActivityThread.java:5221)\r\nW/System.err(16021):    at java.lang.reflect.Method.invoke(Native Method)\r\nW/System.err(16021):    at java.lang.reflect.Method.invoke(Method.java:372)\r\nW/System.err(16021):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)\r\nW/System.err(16021):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)\r\n```\r\n\r\nIf I remove the `animated: true` or the `slide` transition when navigating the issue will not manifest.","author":{"url":"https://github.com/darind","@type":"Person","name":"darind"},"datePublished":"2018-04-13T08:40:47.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/5674/NativeScript/issues/5674"}