Registers a beforeunload event handler for a dashboard page, modal, or plugin extension.
onBeforeUnload() accepts a callback that's triggered when a Wix users is about to navigate away from a dashboard page or when the browsing context of an app is being unloaded. For example, this can happen when the Wix user selects another page from the dashboard's sidebar, or closes the browser tab. If you call onBeforeUnload in the code for a modal extension, the callback triggers when the Wix user is about to close the modal.
The event object passed to the callback function contains a function called preventDefault(). If the callback calls preventDefault(), navigation away from the page or other context unloading is paused. A dialog is displayed in the dashboard warning the Wix user that there may be unsaved data. The Wix user can then choose to cancel and stay in the current context or proceed.
Note: You should not assume that the beforeunload event will always fire or that the confirmation dialog will always be presented. These behaviors vary depending on the Wix user's browser.
| Name | Type | Description |
|---|---|---|
callback | Function | Callback function to call when the beforeunload event fires. The function receives an event object as an argument. |
The event object passed to the callback function.
| Name | Type | Description |
|---|---|---|
preventDefault | Function | Prevents the page from unloading. Opens a dialog with a warning that there may be unsaved data on the page. |
An object containing a method called remove(). Calling this method removes the onBeforeUnload event handler.
Note: To call this method in self-hosted apps, you need to create a client. See the setup guide for more details.