core.js:6406 ERROR TypeError: Cannot read property 'id' of undefined

Question

I have an angular 8 application. And a create function. But I can't create a item, because of the id is null.

Of course I googled for this. But I think this is a specific case.

So this is the the template where the function will be triggered:

<button *ngIf="isNew" mat-raised-button color="primary" [appSubmitIfValid]="editItemForm" (valid)="save()" i18n>Create</button>

and this is the actual function:

  this.dossierService.newDossierItem(this.dossier.id, dossierItemDto)
        .subscribe(item => {
          this.item = item;
          this.dossierItems.unshift(item);
          this.sortDossierItems();
          this.isNew = false;
          form.enable();
          form.markAsPristine();
          this.errorProcessor.openSuccessSnackBar($localize`Item is saved`);
        }, error => this.handleError(error));

and this is my router.ts:

  {
    path: ':dossierId',
    component: ViewComponent, children: [
    {  path: 'item/new/:dossierItemType', component: ItemComponent}
    ],
    resolve: {
      dossier: DossierResolver,
      dossierItems: DossierItemsResolver
    }
  },

So I get an error on this line:

  this.dossierService.newDossierItem(this.dossier.id, dossierItemDto)

that id is null.

But what I have to change?

Thank you

Update:

This is the link for adding a new item: view.component.html:

 <ng-template mat-tab-label #interviews>
          <mat-icon class="interviews">speaker_notes</mat-icon>
          <span i18n>Interview reports</span>{{ dossierItemsCountString(itemTypes.Interview) }}
          <a [routerLink]="['../' , dossier.id , 'item' , 'new',  itemTypes.Interview]">
            <mat-icon class="add_box">add</mat-icon>
          </a>
        </ng-template>

The problem is with routing. Because if I do this:

{
    path: ':dossierId/item/new/:dossierItemType', component: ItemComponent,
    resolve: {
      dossier: DossierResolver,
      dossierItems: DossierItemsResolver
    }
  },

then I can create a new item. But this is not what I want because the new item will be then loaded in a new view.

So that is why I have this:

 {
    path: ':dossierId',
    component: ViewComponent, children: [
    {  path: 'item/new/:dossierItemType', component: ItemComponent}
    ],
    resolve: {
      dossier: DossierResolver,
      dossierItems: DossierItemsResolver
    }
  },

But then dossier is every time null.

this is full item.component.ts code:

export class ItemComponent implements OnInit {
  itemTypes = DossierItemTypeDto;
  formBuilder = new FormBuilder();
  isNew = false;
  editItemForm: FormGroup;
  dossierItemId: string;
  item: DossierItemDto;
  dossierItems: DossierItemDto[];
  dossier: DossierDto;
  globalErrors: ValidationErrors;

  constructor(private dossierService: DossierService, private route: ActivatedRoute, private router: Router,
              private errorProcessor: ErrorProcessor) {

    this.dossier = this.route.snapshot.data.dossier;
    this.dossierItemId = this.route.snapshot.params.dossierItemId;
    this.isNew = this.dossierItemId === undefined;
    this.dossierItems = this.route.snapshot.data.dossierItems;

    if (this.isNew) {
      this.item =  {
        title: '',
        itemType: this.route.snapshot.params.dossierItemType,
        date: moment().format('Y-MM-DD'),
        createdAt: moment().format('Y-MM-DD'),
        body: '' };
    } else {
      this.item = this.dossierItems.find(i => i.id === this.dossierItemId);
    }
  }

  ngOnInit(): void {
    this.editItemForm = this.formBuilder.group({
      title: this.formBuilder.control(this.item.title, [Validators.required]),
      itemType: this.formBuilder.control(this.item.itemType, [Validators.required]),
      date: this.formBuilder.control(moment(this.item.date, 'Y-MM-DD'), [Validators.required]),
      body: this.formBuilder.control(this.item.body, [Validators.required, Validators.maxLength(2097152)])
    });
  }

  save(): void {
    const form = this.editItemForm;
    const dossierItemDto: DossierItemPostDto = {
      title: form.controls.title.value,
      itemType: form.controls.itemType.value,
      date: (form.controls.date.value as moment.Moment).format('Y-MM-DD'),
      body: form.controls.body.value
    };

    form.disable();

    if (!this.isNew) {
      this.dossierService.updateDossierItemById(this.dossier.id, this.item.id, dossierItemDto)
        .subscribe(item => {
          this.item = item;
          this.sortDossierItems();
          form.enable();
          form.markAsPristine();
          this.errorProcessor.openSuccessSnackBar($localize`Item is saved`);
        }, error => this.handleError(error));
    } else {
      this.dossierService.newDossierItem(this.dossier.id, dossierItemDto)
        .subscribe(item => {
          this.item = item;
          this.dossierItems.unshift(item);
          this.sortDossierItems();
          this.isNew = false;
          form.enable();
          form.markAsPristine();
          this.errorProcessor.openSuccessSnackBar($localize`Item is saved`);
        }, error => this.handleError(error));
    }
  }
}

But if I try this:

  {
    path: ':dossierId',
    component: ViewComponent, children: [
    {  path: 'item/new/:dossierItemType', component: ItemComponent}
    ],
    resolve: {
      dossier: DossierResolver,
      dossierItems: DossierItemsResolver
    }
  },

oke, this is weird, Because on this:

ngOnInit(): void {
    this.route.params.subscribe((params: Params) => {
      this.dossier.id = params.dossierId;
    });

in the debugger. I see the first time that the id is set:

"06637e72-8915-4735-9400-4ef7705194ea"

but if I do a f8 then the id is null:

 this.dossier.id = params.dossierId;

and the route I have like this:

  {
    path: ':dossierId',
    component: ViewComponent, children: [
    {  path: 'item/new/:dossierItemType', component: ItemComponent}
    ],
    resolve: {
      dossier: DossierResolver,
      dossierItems: DossierItemsResolver
    }
  },

So this is called two times:

 this.route.params.subscribe((params: Params) => {
      this.dossier.id = params.dossierId;
    });

Dont understand why

Solution 1

Can you try paramsInheritanceStrategy ?

@NgModule({
  imports: [RouterModule.forRoot(routes,{
    paramsInheritanceStrategy: 'always'
})],
  exports: [RouterModule]
})
export class AppRoutingModule { }

You need to capture the parent route params as well

Solution 2

Below code is working for me:

In tsconfig.json of you Angular project

{
  ...
  "angularCompilerOptions": {
    "enableIvy": false
  }
}

Solution 3

Try to use the elvis operator ? . lets say you want to access object.id try object?.id. Usually it happens when you try to access data that maybe be nullable or its reference maybe missing