Validation verifies that user input is correctly formatted and in required fields. Validation occurs at the field-, page-, and form-level.
Field-level validation occurs while focus is in a text input box or immediately after it loses focus. Users get immediate feedback when a problem is found.
Page-level validation occurs when the user attempts to change pages. Form-level validation happens when the user submits the form. A yellow banner identifies incorrect input.
- Provide short, yet informative error text. For example, "A virtual machine with the same name exists. Enter a new name."
- If a validation error is found in a wizard, block forward, but not backwards navigation. The user can correct input on a previous page. Ensure that both the Next button and forward steps in the table of contents are disabled.
- In a multipage dialog, never block navigation between pages because of a validation error. Dialogs do not have interpage dependencies.
- Validate input upon restoring a wizard or dialog from the Work in Progress (WIP) portlet. Show a progress inidcator during validation.
- Restore a wizard to the step that the user was on when the wizard was minimized, or, if an error occurred during validation, the lowest-numbered, invalid step.
- Restore a dialog to the page that the user was last on.
- Assist users in providing correct input. For example, include an instructional label and inline text for a text input box.