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  7. storage.StorageArea
  8. StorageArea.get()

StorageArea.get()

In This Article
  1. Syntax
    1. Parameters
    2. Return value
  2. Browser compatibility
  3. Examples
    1. Chrome examples

Retrieves one or more items from the storage area.

This is an asynchronous function that returns a Promise.

Syntax

let gettingItem = browser.storage.<storageType>.get(
  keys    // null, string, object or array of strings
)

<storageType> will be one of the writable storage types — storage.sync or storage.local.

Parameters

keys
A key (string) or keys (an array of strings or an object specifying default values) to identify the item(s) to be retrieved from storage. If you pass an empty string, object or array here, an empty object will be retrieved. If you pass null, or an undefined value, the entire storage contents will be retrieved.

Return value

A Promise that will be fulfilled with a results object containing every object in keys that was found in the storage area. If the operation failed, the promise will be rejected with an error message.

When used within a content script in Firefox versions prior to 52, the Promise returned by browser.storage.local.get() is fulfilled with an Array containing one Object. The Object in the Array contains the keys found in the storage area, as described above. The Promise is correctly fulfilled with an Object when used in the background context (background scripts, popups, options pages, etc.). When this API is used as chrome.storage.local.get(), it correctly passes an Object to the callback function.

Browser compatibility

ChromeEdgeFirefoxFirefox for AndroidOpera
Basic supportYesYes45.048.033

Examples

Suppose storage contains two items:

// storage contains two items,
// "kittens" and "monsters"
browser.storage.local.set({
  kitten:  {name:"Mog", eats:"mice"},
  monster: {name:"Kraken", eats:"people"}
});

Define success and failure handlers for the promise:

function onGot(item) {
  console.log(item);
}
function onError(error) {
  console.log(`Error: ${error}`);
}

With no keys argument, retrieve everything:

let gettingItem = browser.storage.local.get();
gettingItem.then(onGot, onError);
// -> Object { kitten: Object, monster: Object }

With an empty keys argument, return nothing:

// with an empty array, retrieve nothing
let gettingItem = browser.storage.local.get([]);
gettingItem.then(onGot, onError);
// -> Object { }

With the name of an object, retrieve the match:

let gettingItem = browser.storage.local.get("kitten");
gettingItem.then(onGot, onError);
// -> Object { kitten: Object }

With an array of object names, retrieve all matches:

let gettingItem = browser.storage.local.get(["kitten", "monster", "grapefruit"]);
gettingItem.then(onGot, onError);
// -> Object { kitten: Object, monster: Object } 

With an object with object names as keys and the default value as value:

let gettingItem = browser.storage.local.get({
  kitten: "no kitten",
  monster: "no monster",
  grapefruit: {
    name: "Grape Fruit",
    eats: "Water"
  }
});
// -> Object { kitten: Object, monster: Object, grapefruit: Object }

Chrome examples

chrome.storage.local.get("kitten", function(items){
  console.log(items.kitten);  // -> {name:"Mog", eats:"mice"}
});

Or with an arow function

chrome.storage.local.get("kitten", items=>{
  console.log(items.kitten); // -> {name:"Mog", eats:"mice"}
});
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.

Document Tags and Contributors

Tags: 
  • Add-ons
  • API
  • Extensions
  • get
  • Method
  • Non-standard
  • Reference
  • Storage
  • StorageArea
  • WebExtensions
 Contributors to this page: wbamberg, serv-inc, zekrom-vale, Makyen, freaktechnik, michael-zapata, jonathanKingston, fiveNinePlusR, chrisdavidmills
 Last updated by: wbamberg, Jul 27, 2017, 7:29:43 AM
See also
  1. Browser extensions
  2. Getting started
    1. What are extensions?
    2. Your first extension
    3. Your second extension
    4. Anatomy of an extension
    5. Example extensions
  3. How to
    1. Intercept HTTP requests
    2. Modify a web page
    3. Add a button to the toolbar
    4. Implement a settings page
  4. User interface
    1. Introduction
    2. Toolbar button
    3. Address bar button
    4. Sidebar
    5. Context menu items
    6. Options page
    7. Bundled web pages
    8. Notifications
    9. Address bar suggestions
    10. Developer tools panels
  5. Concepts
    1. Using the JavaScript APIs
    2. Content scripts
    3. Match patterns
    4. Internationalization
    5. Content Security Policy
    6. Native messaging
  6. Porting
    1. Porting a Google Chrome extension
    2. Porting a legacy Firefox extension
    3. Embedded WebExtensions
    4. Comparison with the Add-on SDK
    5. Comparison with XUL/XPCOM extensions
    6. Chrome incompatibilities
    7. Differences between desktop and Android
  7. Firefox workflow
    1. Temporary Installation in Firefox
    2. Debugging
    3. Developing for Firefox for Android
    4. Getting started with web-ext
    5. web-ext command reference
    6. Extensions and the Add-on ID
    7. Publishing your extension
  8. JavaScript APIs
    1. Browser support for JavaScript APIs
    2. alarms
    3. bookmarks
    4. browserAction
    5. browserSettings
    6. browsingData
    7. commands
    8. contextMenus
    9. contextualIdentities
    10. cookies
    11. devtools.inspectedWindow
    12. devtools.network
    13. devtools.panels
    14. downloads
    15. events
    16. extension
    17. extensionTypes
    18. history
    19. i18n
    20. identity
    21. idle
    22. management
    23. notifications
    24. omnibox
    25. pageAction
    26. permissions
    27. privacy
    28. proxy
    29. runtime
    30. sessions
    31. sidebarAction
    32. storage
      1. Properties
        1. local
        2. managed
        3. sync
      2. Types
        1. StorageArea
        2. StorageChange
      3. Events
        1. onChanged
    33. tabs
    34. theme
    35. topSites
    36. types
    37. webNavigation
    38. webRequest
    39. windows
  9. Manifest keys
    1. applications
    2. author
    3. background
    4. browser_action
    5. chrome_settings_overrides
    6. chrome_url_overrides
    7. commands
    8. content_scripts
    9. content_security_policy
    10. default_locale
    11. description
    12. developer
    13. devtools_page
    14. homepage_url
    15. icons
    16. incognito
    17. manifest_version
    18. name
    19. omnibox
    20. optional_permissions
    21. options_ui
    22. page_action
    23. permissions
    24. protocol_handlers
    25. short_name
    26. sidebar_action
    27. theme
    28. version
    29. web_accessible_resources
  10. Themes
  11. Publishing add-ons
  12. Guides
    1. Signing and distribution overview
    2. Submit an add-on
    3. Creating an appealing listing
    4. Review policies
    5. Developer agreement
    6. Featured add-ons
    7. Contact addons.mozilla.org
  13. Community and support
  14. Channels
    1. Add-ons blog
    2. Add-on forums
    3. Stack Overflow
    4. Development newsgroup
    5. IRC Channel
  15. Legacy add-ons
  16. Legacy technologies
    1. Add-on SDK
    2. Legacy Firefox for Android
    3. Bootstrapped extensions
    4. Overlay extensions