title: Angular 7 Form Validation does not show error when clicking submit button
body: <p>I am trying to implement a reset password form with Angular 7 Form Validation as the example in <a href="https://stackblitz.com/edit/angular-8mdfw3" rel="nofollow noreferrer">here</a>. 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? </p>