Dart SDK
dart:html
BeforeUnloadEvent
returnValue
property
returnValue
BeforeUnloadEvent
Properties
returnValue
matchingTarget
bubbles
cancelable
clipboardData
currentTarget
defaultPrevented
eventPhase
path
target
timeStamp
type
Methods
preventDefault
stopImmediatePropagation
stopPropagation
String
returnValue
read / write
(Not documented.)