CODEWITHSUNDEEP
addeventlistenerfirefox-addon-webextensionsfirefox-sidebar
GnxR
GnxR

Reputation: 839

Listen to Firefox WebExtension sidebar closing

I am working on a WebExtension using the sidebar.

When the sidebar is open, the extension performs some operations on the current tab. When it is closed, I want to revert these operations.

Is this possible? I didn't see methods like browser.sidebarAction.addEventListener.

Upvotes: 1

Views: 292

Answers (2)

Aurélien Bénel
Aurélien Bénel

Reputation: 3842

I adapted GnxR's idea in the following:

extension/page/sidebar.html:

<!DOCTYPE html>
<html>
    <body>
        <div id="panel"></div>
        <script src="static.js"></script>
    </body>
</html>

extension/page/static.js:

window.addEventListener('beforeunload', (event) => {
  console.log('Sidebar will be closed!');
  // Do stuff
});
window.addEventListener('pagehide', (event) => {
  console.log('Sidebar is hidden!');
  // Do stuff
});
window.addEventListener('unload', (event) => {
  console.log('Sidebar is unloaded!');
  // Do stuff
});

When closing the extension (both from the cross bar and programmatically), I get the following in the browser console:

Sidebar is hiding! static.js:6:3
Sidebar is unloaded! static.js:10:3

Therefore it seems that both pagehide and unload events can be used, but that beforeunload is never fired.

Upvotes: 3

GnxR
GnxR

Reputation: 839

The sidebar is an alsmot-regular independent webpage, in which you can listen to usual JS events. In order to know when the sidebar is closing, you can use beforeunload in the sidebar's JavaScript:

window.addEventListener('beforeunload', (event) => {
  console.log('Sidebar is closing!');
  // Do stuff
});

Upvotes: 1

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