Angular 7 Form Validation does not show error when clicking submit button

Question

I am trying to implement a reset password form with Angular 7 Form Validation as the example in here . In this example, we have three fields, including old password, new password and confirm password. If I click an input field, such as the old password field without entering any value and then click another input field such as new password field, I will be able to see an error message from the validation. However, if I touch none of three input fields and click update directly, there are no errors displayed. How can I implement the feature that validation errors are displayed for each input field when I click the button?

Answer 1

You have just to replace your div wrapper with a form tag.

stackblitz

<form id='reset-password' [formGroup]='formGroup'>
  <mat-form-field class="reset-password-fields">
    <input matInput required [(ngModel)]="oldPassword" [type]="displayOldPassword ? 'text' : 'password'"
      autocomplete="off" [formControl]="oldPasswordFormControl" [errorStateMatcher]="appErrorMatcher" required>
    <mat-placeholder class="placeholder" color="primary">{{ 'enter-your-old-password' }}</mat-placeholder>
    <mat-icon matSuffix (click)="displayOldPassword = !displayOldPassword">
      {{displayOldPassword ? 'visibility' : 'visibility_off'}}</mat-icon>
    <mat-error *ngIf="oldPasswordFormControl.hasError('required')">
      Old password cannot be
      <strong>empty</strong>
    </mat-error>
  </mat-form-field>
  <mat-form-field class="reset-password-fields">
    <input matInput required [(ngModel)]="newPassword" [type]="displayNewPassword ? 'text' : 'password'"
      autocomplete="off" [formControl]="newPasswordFormControl" [errorStateMatcher]="appErrorMatcher" required>
    <mat-placeholder class="placeholder" color="primary">{{ 'enter-your-new-password' }}</mat-placeholder>
    <mat-icon matSuffix (click)="displayNewPassword = !displayNewPassword">
      {{displayNewPassword ? 'visibility' : 'visibility_off'}}</mat-icon>
    <mat-error *ngIf="newPasswordFormControl.hasError('required')">
      New password cannot be
      <strong>empty</strong>
    </mat-error>
  </mat-form-field>
  <mat-form-field class="reset-password-fields">
    <input matInput required [(ngModel)]="confirmNewPassword" [type]="displayConfirmNewPassword ? 'text' : 'password'"
      autocomplete="off" [formControl]="confirmNewPasswordFormControl" [errorStateMatcher]="appErrorMatcher" required>
    <mat-placeholder class="placeholder" color="primary">{{ 'confirm-your-new-password' }}
    </mat-placeholder>
    <mat-icon matSuffix (click)="displayConfirmNewPassword = !displayConfirmNewPassword">
      {{displayConfirmNewPassword ? 'visibility' : 'visibility_off'}}</mat-icon>
    <mat-error *ngIf="formGroup.invalid">
      Confirm new password does not match password
    </mat-error>
  </mat-form-field>
  <div>
    <button (click)='update()' mat-flat-button color="primary">Update</button>
  </div>
</form>

But you can solve your problem also disabling the button if the form group is invalid:

<button [disabled]="formGroup.invalid" (click)='update()' mat-flat-button color="primary">Update</button>

All the best.