Form data implementation guide in Angular reactive form after asynchronous validation
I'm working on a personal project and I've been researching this but I'm stuck trying to I tried several approaches but none seem to work..... I'm experiencing issues with an Angular reactive form where the data doesn't seem to update properly after an asynchronous validation check. I'm using Angular 15 and trying to implement a custom validator that checks if a username exists in the database. After the API call to validate the username, the form control should update its value, but it seems to retain the previous value. Here's a simplified version of my code: ```typescript import { Component, OnInit } from '@angular/core'; import { FormBuilder, FormGroup, Validators } from '@angular/forms'; import { HttpClient } from '@angular/common/http'; import { map, catchError } from 'rxjs/operators'; @Component({ selector: 'app-user-form', templateUrl: './user-form.component.html', }) export class UserFormComponent implements OnInit { userForm: FormGroup; constructor(private fb: FormBuilder, private http: HttpClient) { this.userForm = this.fb.group({ username: ['', [Validators.required], [this.usernameValidator.bind(this)]], }); } ngOnInit() {} usernameValidator(control) { return this.http.get(`/api/check-username?username=${control.value}`).pipe( map((response: any) => { return response.exists ? { usernameTaken: true } : null; }), catchError(() => null) ); } } ``` In my template, I'm binding the input directly to the `username` control. After the API validation returns, I expect the control to update its state, but it doesn't seem to show the updated behavior message or change the input value. I've tried using `setValue()` after the validation check, but that doesn't seem to work either. I even checked the network tab in my browser, and the API call is returning the expected results, so I'm not sure why the form state isn't reflecting that. I've also ensured that I'm importing `ReactiveFormsModule` in my module. Any ideas on what could be going wrong with the asynchronous validation or the way I'm handling the input? I'm developing on Ubuntu 22.04 with Typescript. This is part of a larger microservice I'm building.