extension

{{AddonSidebar}} 

Utilities related to your extension. Get URLs to resources packages with your extension. Get the Window object for your extension’s pages. Get the values for various settings.

Note: The messaging APIs in this module are deprecated in favor of the equivalent APIs in the runtime module.

Types

• {{WebExtAPIRef("extension.ViewType")}} 
  • : The type of extension view.

Properties

• {{WebExtAPIRef("extension.lastError")}}  {{deprecated_inline}} 
  • : Set for the lifetime of a callback if an asynchronous extension API has resulted in an error. If no error has occurred, lastError will be {{jsxref("undefined")}} .
• {{WebExtAPIRef("extension.inIncognitoContext")}} 
  • : True for content scripts running inside incognito tabs, and for extension pages running inside an incognito process. (The latter only applies to extensions with "incognito": "split" set in their manifest.json file.)

Functions

• {{WebExtAPIRef("extension.getBackgroundPage()")}} 
  • : Returns the Window object for the background page running inside the current extension. Returns null if the extension has no background page.
• {{WebExtAPIRef("extension.getExtensionTabs()")}}  {{deprecated_inline}} 
  • : Returns an array of the JavaScript Window objects for each of the tabs running inside the current extension.
• {{WebExtAPIRef("extension.getURL()")}}  {{deprecated_inline}} 
  • : Converts a relative path within an extension install directory to a fully-qualified URL.
• {{WebExtAPIRef("extension.getViews()")}} 
  • : Returns an array of the Window objects for each of the pages running inside the current extension.
• {{WebExtAPIRef("extension.isAllowedIncognitoAccess()")}} 
  • : Retrieves the state of the extension’s access to Incognito-mode (as determined by the user-controlled ‘Allowed in Incognito’ checkbox).
• {{WebExtAPIRef("extension.isAllowedFileSchemeAccess()")}} 
  • : Retrieves the state of the extension’s access to the file:// scheme (as determined by the user-controlled ‘Allow access to File URLs’ checkbox).
• {{WebExtAPIRef("extension.sendRequest()")}}  {{deprecated_inline}} 
  • : Sends a single request to other listeners within the extension.
• {{WebExtAPIRef("extension.setUpdateUrlData()")}} 
  • : Sets the value of the ap CGI parameter used in the extension’s update URL. This value is ignored for extensions that are hosted in the browser vendor’s store.

Events

• {{WebExtAPIRef("extension.onRequest")}}  {{deprecated_inline}} 
  • : Fired when a request is sent from either an extension process or a content script.
• {{WebExtAPIRef("extension.onRequestExternal")}}  {{deprecated_inline}} 
  • : Fired when a request is sent from another extension.

Browser compatibility

{{Compat}} 

{{WebExtExamples("h2")}} 

[!NOTE] This API is based on Chromium’s chrome.extension API. This documentation is derived from extension.json in the Chromium code.