The beforeunload event is fired when the window, the document and its resources are about to be unloaded.

Documentation BeforeUnloadEvent by Mozilla Contributors, licensed under CC-BY-SA 2.5.

See:

Inherited Variables

Defined by Event

read onlybubbles:Bool

A Boolean indicating whether the event bubbles up through the DOM or not.

cancelBubble:Bool

A historical alias to Event.stopPropagation(). Setting its value to true before returning from an event handler prevents propagation of the event.

read onlycancelable:Bool

A Boolean indicating whether the event is cancelable.

read onlycomposed:Bool

A Boolean value indicating whether or not the event can bubble across the boundary between the shadow DOM and the regular DOM.

read onlycurrentTarget:EventTarget

A reference to the currently registered target for the event. This is the object to which the event is currently slated to be sent; it's possible this has been changed along the way through retargeting.

read onlydefaultPrevented:Bool

Indicates whether or not event.preventDefault() has been called on the event.

read onlyeventPhase:Int

Indicates which phase of the event flow is being processed.

read onlyexplicitOriginalTarget:EventTarget

The explicit original target of the event (Mozilla-specific).

read onlyisTrusted:Bool

Indicates whether or not the event was initiated by the browser (after a user click for instance) or by a script (using an event creation method, like event.initEvent).

read onlyoriginalTarget:EventTarget

The original target of the event, before any retargetings (Mozilla-specific).

returnValue:Bool

A historical property introduced by Internet Explorer and eventually adopted into the DOM specification in order to ensure existing sites continue to work. Ideally, you should try to use Event.preventDefault() and Event.defaultPrevented instead, but you can use returnValue if you choose to do so.

read onlytarget:EventTarget

A reference to the target to which the event was originally dispatched.

read onlytimeStamp:Float

The time at which the event was created (in milliseconds). By specification, this value is time since epoch, but in reality browsers' definitions vary; in addition, work is underway to change this to be a DOMHighResTimeStamp instead.

read onlytype:String

The name of the event (case-insensitive).

Inherited Methods

Defined by Event

composedPath ():Array<EventTarget>

Returns the event’s path (objects on which listeners will be invoked). This does not include nodes in shadow trees if the shadow root was created with its ShadowRoot.mode closed.

@:value({ cancelable : false, bubbles : false })initEvent (type:String, bubbles:Bool = false, cancelable:Bool = false):Void

Initializes the value of an Event created. If the event has already being dispatched, this method does nothing.

preventDefault ():Void

Cancels the event (if it is cancelable).

stopImmediatePropagation ():Void

For this particular event, no other listener will be called. Neither those attached on the same element, nor those attached on elements which will be traversed later (in capture phase, for instance)

stopPropagation ():Void

Stops the propagation of events further along in the DOM.