Build Reactive Websites with RxJS

Using Advanced Validation

Form validation is more than just ensuring the user entered something into each element. It can be a cruical asset for users on phones (where a contextual keyboard will pop up on the phone), folks who use screen readers, or people who are just in a hurry and don’t notice minor mistakes. In all of these cases, having the form pop up reminders, as soon as it knows what’s wrong, will be a boon for the user. Let’s dive into validation beyond a basic phone number and brainstorm a few rules about our form.

Inline Error Messages
	For the remainder of this chapter, I’ll skip adding the error messages to the form to keep focus ...