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ViewDestroyedError: Attempting to use a destroyed view: detectChanges

I have the following component that creates MdDialog

export class SideNavsComponent implements OnInit, AfterViewInit, OnDestroy {
  eventDispatcher: EventDispatcher
  authEmailDialogRef: MdDialogRef<AuthEmailDialogComponent>

  constructor(public dialog: MdDialog,) {
    this.eventDispatcher = new EventDispatcher()
  }

  signIn( event ): void {
    this.isSignedIn = event.checked
    this.openDialog()
  }

  openDialog() {
    this.authEmailDialogRef = this.dialog.open( AuthEmailDialogComponent, {
      height: '500px',
      width: '300px',
      disableClose: true
    } )
  }

  ngOnDestroy() {
  }

  ngAfterViewInit() {
  }

  ngOnInit() {
    event_dispatcher.on( 'CLOSE authEmailDialogRef', ( target: Object ) => {
      this.authEmailDialogRef.close()
    } )
  }
}

The component below creates a button that, when clicked, closes the above-created MdDialog by dispatch and an event that is intercepted in the SideNavsComponent # ngOnInit method

export class AuthEmailDialogComponent implements OnInit {
eventDispatcher: EventDispatcher = new EventDispatcher()
}

cancel() {
      event_dispatcher.dispatch( 'CLOSE authEmailDialogRef', '')
  }
}

MdDialog closed (), but change detection error always happens with the following:

ERROR Error: ViewDestroyedError: Attempt to use a destroyed view: detectChanges
    at viewDestroyedError (core.es5.js:8636)
    at Object.debugUpdateDirectives [as updateDirectives] (core.es5.js:12781)
    at checkAndUpdateView (core.es5.js:12122)
    at callWithDebugContext (core.es5.js:13184)
    at Object.debugCheckAndUpdateView [as checkAndUpdateView] (core.es5.js:12724)
    at ViewRef_.detectChanges (core.es5.js:10196)
    at asterisk.component.ts:37
    at ZoneDelegate.webpackJsonp.1467.ZoneDelegate.invokeTask (zone.js:414)
    at Object.onInvokeTask (core.es5.js:4119)
    at ZoneDelegate.webpackJsonp.1467.ZoneDelegate.invokeTask (zone.js:413)
View_MdDialogContainer_Host_0 @ MdDialogContainer_Host.html:1
proxyClass @ compiler.es5.js:14091
DebugContext_.logError @ core.es5.js:13124
ErrorHandler.handleError @ core.es5.js:1144
next @ core.es5.js:4757
schedulerFn @ core.es5.js:3830
SafeSubscriber.__tryOrUnsub @ Subscriber.js:236
SafeSubscriber.next @ Subscriber.js:185
Subscriber._next @ Subscriber.js:125
Subscriber.next @ Subscriber.js:89
Subject.next @ Subject.js:55
EventEmitter.emit @ core.es5.js:3816
NgZone.triggerError @ core.es5.js:4188
onHandleError @ core.es5.js:4149
webpackJsonp.1467.ZoneDelegate.handleError @ zone.js:385
webpackJsonp.1467.Zone.runTask @ zone.js:184
ZoneTask.invoke @ zone.js:476
timer @ zone.js:1491
setInterval (async)
scheduleTask @ zone.js:1501
webpackJsonp.1467.ZoneDelegate.scheduleTask @ zone.js:400
onScheduleTask @ zone.js:290
webpackJsonp.1467.ZoneDelegate.scheduleTask @ zone.js:394
webpackJsonp.1467.Zone.scheduleTask @ zone.js:225
webpackJsonp.1467.Zone.scheduleMacroTask @ zone.js:248
(anonymous) @ zone.js:1527
proto.(anonymous function) @ zone.js:1402
AsteriskComponent @ asterisk.component.ts:37
createClass @ core.es5.js:10870
createDirectiveInstance @ core.es5.js:10701
createViewNodes @ core.es5.js:12064
callViewAction @ core.es5.js:12508
execComponentViewsAction @ core.es5.js:12417
createViewNodes @ core.es5.js:12091
createRootView @ core.es5.js:11969
callWithDebugContext @ core.es5.js:13184
debugCreateRootView @ core.es5.js:12644
ComponentFactory_.create @ core.es5.js:9890
ComponentFactoryBoundToModule.create @ core.es5.js:3427
ViewContainerRef_.createComponent @ core.es5.js:10092
PortalHostDirective.attachComponentPortal @ material.es5.js:2135
MdDialogContainer.attachComponentPortal @ material.es5.js:19218
MdDialog._attachDialogContent @ material.es5.js:19486
MdDialog.open @ material.es5.js:19400
webpackJsonp.751.SideNavsComponent.openDialog @ side-navs.component.ts:39
webpackJsonp.751.SideNavsComponent.signIn @ side-navs.component.ts:35
(anonymous) @ SideNavsComponent.html:32
handleEvent @ core.es5.js:11892
callWithDebugContext @ core.es5.js:13184
debugHandleEvent @ core.es5.js:12772
dispatchEvent @ core.es5.js:8792
(anonymous) @ core.es5.js:10720
schedulerFn @ core.es5.js:3842
SafeSubscriber.__tryOrUnsub @ Subscriber.js:236
SafeSubscriber.next @ Subscriber.js:185
Subscriber._next @ Subscriber.js:125
Subscriber.next @ Subscriber.js:89
Subject.next @ Subject.js:55
EventEmitter.emit @ core.es5.js:3816
ToggleButton.toggle @ togglebutton.js:42
(anonymous) @ ToggleButton.html:4
handleEvent @ core.es5.js:11892
callWithDebugContext @ core.es5.js:13184
debugHandleEvent @ core.es5.js:12772
dispatchEvent @ core.es5.js:8792
(anonymous) @ core.es5.js:9384
(anonymous) @ platform-browser.es5.js:2683
webpackJsonp.1467.ZoneDelegate.invokeTask @ zone.js:414
onInvokeTask @ core.es5.js:4119
webpackJsonp.1467.ZoneDelegate.invokeTask @ zone.js:413
webpackJsonp.1467.Zone.runTask @ zone.js:181
ZoneTask.invoke @ zone.js:476
MdDialogContainer_Host.html:1 ERROR CONTEXT DebugContext_ {view: {…}, nodeIndex: 0, nodeDef: {…}, elDef: {…}, elView: {…}}

How can I prevent changeDetection from firing after the component is destroyed; in other words, how can I get this code to work without error?

NB: Tried many suggestions on stackoverflow but none worked.

thank

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3 answers


The problem is that the dialog is closing the activity by removing the item from the view and your EventDispatcher IS NOT A CORNER POSITION METHOD , so it runs out of the zone context and pisses it off. It looks like this:

  • Dialogue exists in sight, sets state
  • Clicks close
  • Launches your event to start
  • Your event has been read (out of context)
  • Removes from view (still out of context)
  • Change detection is finally catching up with changes in your component, OH SNEP WHERE IS THE COMPONENT?

You can use a different method to interact with the dialog or switch to onPush () to detect changes



I suggest you use a pen afterClosed

:

this. authEmailDialogRef.afterClosed().subscribe(result => {
  console.log('Dialog result: ${result}'); // Pizza!
});

I pulled this snippet straight from the docs: HERE

+11


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The cause of this issue is that you are removing the reference to sortableData or dragableData in a change event. in the abstract class, the detectChange method waits 250ms before triggering change detection, at which time your view and component will be destroyed.



setTimeout(() => {
        if (this.cdr !== null && this.cdr !== undefined &&
          !(this.cdr as ViewRef_).destroyed) {
          this.cdr.detectChanges();
        }
      }, 250);
+1


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Padegal Saigiriraj is right. But ViewRef_

use instead ViewRef

. Shortly speaking:

setTimeout(() => {
  if (this.cdr && !(this.cdr as ViewRef).destroyed) {
    this.cdr.detectChanges();
  }
});

ViewRef stands for Angular, specifically Host View as described by Angular site .

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