angular - 如何获取没有 exportAs 的指令的参考

Question

clrDate is a custom third party directive without an exportAs statement.

source code

@Directive({
  selector: '[clrDate]',
  host: {
    '[class.clr-input]': 'true',
  },
  providers: [DatepickerFocusService],
})
export class ClrDateInput extends WrappedFormControl<ClrDateContainer> implements OnInit, AfterViewInit, OnDestroy {
  @Input() placeholder: string;
  @Output('clrDateChange') dateChange: EventEmitter<Date> = new EventEmitter<Date>(false);
  @Input('clrDate')
...
}

I want to be able to get a reference to it from inside my controller as well as my customDirective. How can I do that?

<clr-date-container customDirective>
    <label for="dateControl">Requirement Date</label>
    <input id="dateControl" type="date" [placeholder]="'TT.MM.YYYY'" [(clrDate)]="item.requirementDate" (clrDateChange)="onChange($event)" [ngModel]="null" name="requirementDate"/>
    <clr-control-error>{{ 'FORMS.VALIDATION.DATE_INVALID' | translate }}</clr-control-error>
</clr-date-container>

Answer 1

Add #ref (template variable) on the directive and you can get it in the component

Answer 2

Depending on from where you want to access the directive instance, you should be able to get hands on it via @ViewChild or constructor injection.

From your controller (component) or from your customDirective you should be able to do following:

  // will be available in ngOnInit
  @ViewChild(ClrDateInput, { static: true })
  clrDateDirective: ClrDateInput;

assuming you can have multiple ClrDateInput directives you could use @ViewChildren :

  // will be available in ngAfterViewInit
  @ViewChildren(ClrDateInput)
  clrDateDirectives: QueryList<ClrDateInput>;

from the host element of the directive itself you can inject the directive via constructor injection:

// app.component.html
<custom-app ctrlDate></custom-app>

// custom-app.component.ts
@Component({
  selector: "custom-app",
  template: `
    <h2>Custom App</h2>
  `
})
class CustomAppComponent {
    constructor(@Self() private ClrDateInput: ClrDateInput) {}

You can take a look at a example sandbox .