How to add custom validator to reactive forms in Angular5 - angular5

Question

I have the following passwordvalidator which I don't know how to attach into the html. The way I am invoking it now it's not working loginForm.controls.password.errors.passwordValidator
See below in the actual code.
import { FormControl } from "#angular/forms";
export class PasswordValidator {
static getPasswordValidator() {
return function passwordValidator(control: FormControl): { [s: string]: boolean } {
// Write code here..
if (!control.value.match(/^((?=.*[a-z])(?=.*[A-Z])(?=.*[0-9]).{6,})/)) {
return { invalidPassword: true };
}
return null;
}
}
}
Then this is how I am using it in login.ts
ngOnInit() {
this.loginForm = this.fb.group({
username: ['', [Validators.required, Validators.email]],
password: ['',
Validators.compose([
Validators.required,
PasswordValidator.getPasswordValidator()
]
)]
});
}
But can't find out how to add it to the formcontrol in login.html
<mat-form-field class="example-full-width">
<input id="password" formControlName="password" matInput placeholder="Password">
</mat-form-field>
<br>
<div *ngIf="loginForm.controls.password.invalid && (loginForm.controls.password.dirty || loginForm.controls.password.touched)"
class="alert alert-danger">
<div class="error mat-body-2" *ngIf="loginForm.controls.password.errors.required">
You must fill out your password
</div>
<div class="error mat-body-2" *ngIf="loginForm.controls.password.errors.passwordValidator && !loginForm.controls.password.errors.required">
Invalid email password
</div>

Answer 1

You should check if the key invalidPassword exist in errors of that controls or not like that
<mat-form-field class="example-full-width">
<input id="password" formControlName="password" matInput placeholder="Password">
</mat-form-field>
<br>
<div *ngIf="loginForm.controls.password.invalid && (loginForm.controls.password.dirty || loginForm.controls.password.touched)"
class="alert alert-danger">
<div class="error mat-body-2" *ngIf="loginForm.controls.password.errors.required">
You must fill out your password
</div>
<div class="error mat-body-2" *ngIf="loginForm.controls.password.errors.invalidPassword && !loginForm.controls.password.errors.required">
Invalid email password
</div>