Interface BeforeUnloadCallback

All Superinterfaces:
AsyncCallback<BeforeUnloadCallback.Params,BeforeUnloadCallback.Action>, BrowserAsyncCallback<BeforeUnloadCallback.Params,BeforeUnloadCallback.Action>, BrowserCallback, Callback
All Known Implementing Classes:
DefaultBeforeUnloadCallback, DefaultBeforeUnloadCallback, DefaultBeforeUnloadCallback

This callback is invoked when the web page is about to be unloaded.

Some web pages may override the window.onbeforeunload JavaScript function, so that a confirmation dialog will be shown every time when the user tries to reload a web page or navigate to another web page. You can use this callback to display an appropriate confirmation message dialog to ask the user if they really want to leave or reload the web page. To find out whether the web page is going to be reloaded you can check the BeforeUnloadCallback.Params.isReload() method.

Use the BeforeUnloadCallback.Action.stay() method to stay on the current web page.

Use the BeforeUnloadCallback.Action.leave() method to reload or navigate to another web page.

If the callback throws an exception, the BeforeUnloadCallback.Action.leave() method will be invoked.