Fired when one or more items change.
Syntax
browser.storage.onChanged.addListener(listener) browser.storage.onChanged.removeListener(listener) browser.storage.onChanged.hasListener(listener)
Events have three functions:
addListener(callback)
- 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
callback
-
Function that will be called when this event occurs. The function will be passed the following arguments:
changes
object
. Object describing the change. This contains one property for each key that changed. The name of the property is the name of the key that changed, and its value is astorage.StorageChange
object describing the change to that item.
areaName
string
. The name of the storage area ("sync"
,"local"
or"managed"
) to which the changes were made.
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Chrome | Edge | Firefox | Firefox for Android | Opera | |
---|---|---|---|---|---|
Basic support | Yes | Yes | 45 | 48 | Yes |
Examples
/* Log the storage area that changed, then for each item changed, log its old value and its new value. */ function logStorageChange(changes, area) { console.log("Change in storage area: " + area); var changedItems = Object.keys(changes); for (var item of changedItems) { console.log(item + " has changed:"); console.log("Old value: "); console.log(changes[item].oldValue); console.log("New value: "); console.log(changes[item].newValue); } } browser.storage.onChanged.addListener(logStorageChange);
Example extensions
Acknowledgements
This API is based on Chromium's chrome.storage
API. This documentation is derived from storage.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.
// Copyright 2015 The Chromium Authors. All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following disclaimer // in the documentation and/or other materials provided with the // distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.