Angular 15: solution with Reactive Form State implementation guide After Async Validation
I'm collaborating on a project where I've looked through the documentation and I'm still confused about I'm working with Angular 15 and working with an scenario where the state of my reactive form isn't updating correctly after an asynchronous validation function is executed. I have a simple form with a username field that checks against a backend API to verify if the username is taken. The validation function is set up correctly, but I noticed that the form control's `status` is not reflecting the updated validation result. Here's the relevant part of my form setup: ```typescript import { Component, OnInit } from '@angular/core'; import { FormBuilder, FormGroup, Validators } from '@angular/forms'; import { HttpClient } from '@angular/common/http'; import { map } from 'rxjs/operators'; @Component({ selector: 'app-username-form', templateUrl: './username-form.component.html', }) export class UsernameFormComponent implements OnInit { usernameForm: FormGroup; constructor(private fb: FormBuilder, private http: HttpClient) {} ngOnInit() { this.usernameForm = this.fb.group({ username: ['', [Validators.required], [this.usernameAsyncValidator.bind(this)]], }); } usernameAsyncValidator(control) { return this.http.get(`/api/check-username?username=${control.value}`).pipe( map((response: any) => { return response.exists ? { usernameTaken: true } : null; }) ); } } ``` In the component template, I have the following: ```html <form [formGroup]="usernameForm" (ngSubmit)="onSubmit()"> <input formControlName="username" /> <div *ngIf="usernameForm.get('username').hasError('usernameTaken')">Username is already taken.</div> <button type="submit">Submit</button> </form> ``` Even when the API returns that the username is taken, the form control doesn't update the behavior state accordingly. I have tried manually marking the control as `touched` or `dirty`, but that didn't help. The response from the API is returning correctly, and I can see it in the network tab, but the form's state doesn't change. I also added logging inside the async validator to verify that it is being called, but the control's behavior state remains unchanged. What am I missing here? Any insights into why the async validation might not be updating the form state correctly would be greatly appreciated! I'm working on a API that needs to handle this. I'm working with Typescript in a Docker container on Windows 11. I'd be grateful for any help.