Validation on a form means showing the user some feedback that there’s a problem with some of the information they’ve painstakingly entered.
Validate data entered into a field as soon as possible, when the user moves to the next field, so you know they’re done typing in the current one.
Client-side validation isn’t always technically possible, but you should aim for it wherever you can because the “round trip” to the server and back is frustrating if there are errors.
Figure 51.1: Tell the user to try again before they submit the form
There are lots of techniques for doing this, including plenty of ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month, and much more.
