New window opens automatically without warning
unexpected-window-launch
Rule
Changing an element's value MUST NOT automatically trigger a change of context, unless the user is adequately advised ahead of time.
Background
People expect that selecting a link or a button may cause a change of context - such as a opening a new window or page, moving focus to another element, a submitting a form. Whenever the mere act of entering text into an edit box, checking a checkbox or radio button, or navigating to an option in a select control causes an unexpected change in context, some users - especially people with vision or cognitive disabilities - may become quite disoriented or confused. Changes in context should only occur when selecting a link or button - not when changing the setting of a checkbox, radio button or select - unless the user is informed ahead of time. This will ensure that users can interact with a page in a predictable manner.
How to Fix
Fix this issue by using ONE of the following techniques:
- Ensure that entering text into an edit box, checking a checkbox or radio button, or navigating to one of the options of a select control does not automatically open a new window.
- Inform users ahead of time of such behavior by methods such as the text label for the UI control or some advisory text placed before the control that cautions the user of this behavior.