How to not emit event while editing a Form Control value in Angular 2

Question

I am trying to write an autocomplete input field using Angular2 and Form Control.

First I decided to initialize my form Control as follow:

term = new FormControl();  constructor(private _autocompleteService: AutocompleteService) {   this.term.valueChanges       .debounceTime(300)       .distinctUntilChanged()       .flatMap(search => this._autocompleteService.autocomplete(this.urlSearch, search))       .subscribe(           autocomplete => this.autocomplete = autocomplete,           error => console.log(error)       ); } 

_autocompleteService sends the search request to the server and returns an array of strings.

My html template looks like this. It shows a list of suggestions under the input in which each element can be selected.

<input type="text" [formControl]="term">   <ul>     <li *ngFor="let suggestion of autocomplete" (click)="selectChoice(suggestions)">{{ suggestion }}</li>   </ul> 

And here is the selection function:

selectChoice(choice: string) {   this.autocomplete = [];       // We clean the list of suggestions   this.term.setValue(choice);   // We write the choice in the term to see it in the input   this.selected = resp; } 

Here is the problem. When I edit `value` from `term`, it emits an event and sends a new search request which then displays a new list of suggestions.

Is there a way to prevent this event emission and just change the value displayed in the input field?

Answer 1

According to the docs you can do the following:

selectChoice(choice: string) {   this.autocomplete = [];  // We clean the list of suggestions   this.term.setValue(choice, { emitEvent: false }); // We write the choice in the term to see it in the input   this.selected = resp; } 

emitEvent: false will prevent the valueChanges event from being emitted.

If emitEvent is true, this change will cause a valueChanges event on the FormControl to be emitted. This defaults to true (as it falls through to updateValueAndValidity).