index.md

---

title: sidebarAction.setPanel()
slug: Mozilla/Add-ons/WebExtensions/API/sidebarAction/setPanel
page-type: webextension-api-function
tags:
  - API
  - Add-ons
  - Extensions
  - Method
  - Reference
  - WebExtensions
  - setPanel
  - sidebarAction
browser-compat: webextensions.api.sidebarAction.setPanel

---

{{AddonSidebar()}}

Sets the sidebar's panel: that is, the HTML document that defines the content of this sidebar.

Types of panel

Sidebars always have a "manifest panel", which is the panel defined in the sidebar_action manifest key.

If you set a new panel using setPanel(), and include the tabId option, then the panel is set only for the given tab. This panel is referred to as the "tab-specific panel".

If you set a new panel using setPanel(), and include the windowId option, then the panel is set only for the given window. This panel is referred to as the "window-specific panel", and will appear in all tabs of that window that do not have a tab-specific panel set.

If you set a new panel using setPanel(), and omit both the tabId and windowId options, then this sets the "global panel". The global panel will then appear in all tabs that do not have a tab-specific panel set and whose window does not have a window-specific panel.

Syntax

browser.sidebarAction.setPanel(
  details // object
)

Parameters

• details

  • : object. An object with the following properties:

    • panel

      • : string or null. The panel to load into the sidebar, specified as a URL pointing to an HTML document, or null, or an empty string.

        This can point to a file packaged within the extension (for example, created using {{WebExtAPIRef("runtime.getURL")}}), or a remote document (e.g. https://example.org/). It must be a valid URL.

        If panel is null or "", then a previously set panel will be removed, so that:

        • If tabId is specified, and the tab has a tab-specific panel set, then the tab will inherit the panel from the window it belongs to.

        • If windowId is specified, and the window has a window-specific panel set, then the window will inherit the global panel.

        • Otherwise, the global panel will be reset to the manifest panel.

    • tabId {{optional_inline}}

      • : integer. Sets the panel only for the given tab.

    • windowId {{optional_inline}}

      • : integer. Sets the panel only for the given window.

• If windowId and tabId are both specified, the function fails and the panel is not set.

• If windowId and tabId are both omitted, the global panel is set.

Examples

This code toggles the sidebar document when the user clicks a browser action:

let thisPanel = browser.runtime.getURL("/this.html");
let thatPanel = browser.runtime.getURL("/that.html");

function toggle(panel) {
  if (panel === thisPanel) {
    browser.sidebarAction.setPanel({panel: thatPanel});
  } else {
    browser.sidebarAction.setPanel({panel: thisPanel});
  }
}

browser.browserAction.onClicked.addListener(() => {
  browser.sidebarAction.getPanel({}).then(toggle);
});

{{WebExtExamples}}

Browser compatibility

{{Compat}}

Note: This API is based on Opera's chrome.sidebarAction API.