extension

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 that the messaging APIs in this module are deprecated in favor of the equivalent APIs in the runtime module.

Types

extension.ViewType: The type of extension view.

Properties

extension.lastError: Set for the lifetime of a callback if an ansychronous extension api has resulted in an error. If no error has occured lastError will be undefined.
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 'split' incognito_behavior.

Functions

extension.getURL(): Converts a relative path within an extension install directory to a fully-qualified URL.
extension.getViews(): Returns an array of the Window objects for each of the pages running inside the current extension.
extension.getBackgroundPage(): Returns the Window object for the background page running inside the current extension. Returns null if the extension has no background page.
extension.isAllowedIncognitoAccess(): Retrieves the state of the extension's access to Incognito-mode (as determined by the user-controlled 'Allowed in Incognito' checkbox).
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).
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

extension.onRequest: Fired when a request is sent from either an extension process or a content script.
extension.onRequestExternal: Fired when a request is sent from another extension.

Browser compatibility

	Chrome	Edge	Firefox	Firefox for Android	Opera
`ViewType`	Yes	No	45	48	Yes
`getBackgroundPage`	Yes	Yes	45	48	Yes
`getExtensionTabs`	Yes	No	No	No	No
`getURL`	Yes	Yes	45	48	Yes
`getViews`	Yes	No	45	48	Yes
`inIncognitoContext`	Yes	No	45	48	Yes
`isAllowedFileSchemeAccess`	Yes	No	48	48	Yes
`isAllowedIncognitoAccess`	Yes	No	48	48	Yes
`lastError`	Yes	No	47	48	Yes
`onRequest`	Yes	No	No	No	Yes
`onRequestExternal`	Yes	No	No	No	Yes
`sendRequest`	Yes	No	No	No	No
`setUpdateUrlData`	Yes	No	No	No	Yes

Edge incompatibilities

Promises are not supported in Edge. Use callbacks instead.

Chrome incompatibilities

None.

Example extensions

Acknowledgements

This API is based on Chromium's chrome.extension API. This documentation is derived from extension.json in the Chromium code.

Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.

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