René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Next] Back Navigation crashing the app w/ The specified child already has a parent","articleBody":"Working with `next` of `tns-core-modules` and `nativescript-angular` and navigating with`nsRouterLink` and then back with the hardware button is causing a crash.\r\n\r\nSteps to reproduce:\r\n- Use [this demo branch ](https://github.com/NickIliev/nativescript-ng-cosmos/tree/niliev/nsrouterlink-bug)\r\n\r\n- Load the app and the initial page will load with a closed sidedrawer. [Navigation through the sidedrawer](https://github.com/NickIliev/nativescript-ng-cosmos/blob/niliev/nsrouterlink-bug/app/app.component.html#L9) and **back** (to **\"Details\"**) is working as expected. \r\n\r\n- Navigate to the same details page[ via nsRouterLink](https://github.com/NickIliev/nativescript-ng-cosmos/blob/niliev/nsrouterlink-bug/app/pages/main/main.component.html#L9) by pressing the page upper content and then navigate back and the application will crash with:\r\n```\r\nJS: NavigationEnd(id: 4, url: '/info', urlAfterRedirects: '/info/app-info')\r\nJS: NavigationEnd(id: 4, url: '/info', urlAfterRedirects: '/info/app-info')\r\nJS: Router Event: Scroll\r\nJS: Scroll(anchor: 'null', position: 'null')\r\nJS: Scroll(anchor: 'null', position: 'null')\r\nSystem.err: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.\r\nSystem.err:     at android.view.ViewGroup.addViewInner(ViewGroup.java:5122)\r\nSystem.err:     at android.view.ViewGroup.addView(ViewGroup.java:4953)\r\nSystem.err:     at android.view.ViewGroup.addView(ViewGroup.java:4893)\r\nSystem.err:     at android.view.ViewGroup.addView(ViewGroup.java:4866)\r\nSystem.err:     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1425)\r\nSystem.err:     at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1750)\r\nSystem.err:     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1819)\r\nSystem.err:     at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:797)\r\nSystem.err:     at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2590)\r\nSystem.err:     at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2377)\r\nSystem.err:     at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2332)\r\nSystem.err:     at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2239)\r\nSystem.err:     at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:700)\r\n...\r\n```\r\n\r\npackage.json content using **next**\r\n```JSON\r\n  \"dependencies\": {\r\n    \"@angular/common\": \"~6.1.0\",\r\n    \"@angular/compiler\": \"~6.1.0\",\r\n    \"@angular/core\": \"~6.1.0\",\r\n    \"@angular/forms\": \"~6.1.0\",\r\n    \"@angular/http\": \"~6.1.0\",\r\n    \"@angular/platform-browser\": \"~6.1.0\",\r\n    \"@angular/platform-browser-dynamic\": \"~6.1.0\",\r\n    \"@angular/router\": \"~6.1.0\",\r\n    \"nativescript-angular\": \"^6.2.0-2018-09-14-01\",\r\n    \"nativescript-app-center\": \"^1.0.3\",\r\n    \"nativescript-cardview\": \"^3.1.1\",\r\n    \"nativescript-permissions\": \"^1.2.3\",\r\n    \"nativescript-plugin-firebase\": \"^6.8.1\",\r\n    \"nativescript-social-share\": \"^1.5.1\",\r\n    \"nativescript-theme-core\": \"^1.0.4\",\r\n    \"nativescript-ui-sidedrawer\": \"^4.3.0\",\r\n    \"reflect-metadata\": \"~0.1.8\",\r\n    \"rxjs\": \"^6.0.0\",\r\n    \"tns-core-modules\": \"^4.3.0-2018-09-14-01\",\r\n    \"zone.js\": \"^0.8.26\"\r\n  },\r\n  \"devDependencies\": {\r\n    \"@angular/compiler-cli\": \"~6.1.0\",\r\n    \"@ngtools/webpack\": \"~6.2.0\",\r\n    \"nativescript-dev-typescript\": \"~0.7.3\",\r\n    \"nativescript-dev-webpack\": \"^0.17.0-2018-09-14-01\",\r\n    \"tns-platform-declarations\": \"^4.2.0\",\r\n    \"typescript\": \"~2.7.2\"\r\n  },\r\n```\r\n\r\nThe above case is working as expected with official versions of nativescript-angular and tns-core-modules. The navigation also works when `routerExtensions` is used ins tead of `nsRouterLink`\r\n\r\nWorkaround\r\n```TS\r\nthis._routerExtensions.navigate(\r\n                [path], {\r\n                transition: {\r\n                    name: \"fade\",\r\n                    duration: 300,\r\n                }\r\n            }\r\n        )\r\n```","author":{"url":"https://github.com/NickIliev","@type":"Person","name":"NickIliev"},"datePublished":"2018-09-14T14:05:51.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/1516/nativescript-angular/issues/1516"}