extension API
The browser.extension API has utilities that can be used by any extension page. It includes support for exchanging messages between an extension and its content scripts or between extensions, as described in detail in $(topic:messaging)[Message Passing].
Functions
getBackgroundPage()
Returns the JavaScript ‘window’ object for the background page running inside the current extension. Returns null if the extension has no background page.
getURL(path)
Converts a relative path within an extension install directory to a fully-qualified URL.
Parameters
path
(string)
A path to a resource within an extension expressed relative to its install directory.
Return type (Promise)
string
The fully-qualified URL to the resource.
getViews([fetchProperties])
Returns an array of the JavaScript ‘window’ objects for each of the pages running inside the current extension.
Parameters
[fetchProperties]
(object, optional)
[tabId]
(integer, optional)
Find a view according to a tab id. If this field is omitted, returns all views.
The type of view to get. If omitted, returns all views (including background pages and tabs). Valid values: ‘tab’, ‘popup’, ‘sidebar’.
[windowId]
(integer, optional)
The window to restrict the search to. If omitted, returns all views.
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.
isAllowedIncognitoAccess()
Retrieves the state of the extension’s access to Incognito-mode (as determined by the user-controlled ‘Allowed in Incognito’ checkbox.
Return type (Promise)
boolean
True if the extension has access to Incognito mode, false otherwise.
Events
Types
ViewType
The type of extension view.
string
Supported values:
tab
popup
sidebar
Properties
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.
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.