cookies.onChanged
The onChanged
event of the cookies
API fires when a cookie that the extension can access is set or removed.
Note: When storage partitioning is active, cookies.Cookie.partitionKey
contains the description of the cookie's storage partition. When modifying cookies, it's important to pass this value to cookies.set()
or cookies.remove()
to ensure the extension works with the correct cookie.
Note that updating a cookie's properties is implemented as a two step process:
- First, the cookie to be updated is first removed entirely, generating a notification with a
cookies.OnChangedCause
ofoverwrite
. - Next, a new cookie is written with the updated values, generating a second notification with a
cookies.OnChangedCause
ofexplicit
.
Syntax
browser.cookies.onChanged.addListener(listener)
browser.cookies.onChanged.removeListener(listener)
browser.cookies.onChanged.hasListener(listener)
This API is also available as browser.cookies.onChanged.*
.
Events have three functions:
addListener(listener)
-
Adds a listener to this event.
removeListener(listener)
-
Stop listening to this event. The
listener
argument is the listener to remove. hasListener(listener)
-
Check whether
listener
is registered for this event. Returnstrue
if it is listening,false
otherwise.
addListener syntax
Parameters
listener
-
The function called when this event occurs. The function is passed these arguments:
changeInfo
-
An
object
containing details of the change that occurred. Its properties are as follows:removed
-
A
boolean
that is set totrue
if a cookie was removed, and false if not. -
A
cookies.Cookie
object containing information about the cookie that was set or removed. cause
-
A
cookies.OnChangedCause
value representing the underlying reason behind the cookie's change.
Browser compatibility
BCD tables only load in the browser
Examples
This example listens for onChanged
events and logs details from the changeInfo
argument:
browser.cookies.onChanged.addListener((changeInfo) => {
console.log(
`Cookie changed: \n` +
` * Cookie: ${JSON.stringify(changeInfo.cookie)}\n` +
` * Cause: ${changeInfo.cause}\n` +
` * Removed: ${changeInfo.removed}`,
);
});
Example extensions
Note: This API is based on Chromium's chrome.cookies
API. This documentation is derived from cookies.json
in the Chromium code.