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  7. sessions.Session

sessions.Session

In This Article
  1. Type
  2. Browser compatibility

The Session object represents a tab or window that the user has closed in the current browsing session.

Sessions are represented as Tab objects if the tab was closed but its window was not closed: for example, because the user clicked the "Close tab" button, and this tab was not the only tab in its window.

Sessions are represented as Window objects if the window was closed: for example, because the user clicked the "Close window" button, or closed the only tab open in a window.

Note that different browsers might have a different idea of when a session is a Tab and when it is a Window. For example:

  • In Chrome a session is recorded as a Window if the user closes a window that contained more than one tab. If the user closed a window that contained only one tab, this is recorded as a Tab.
  • In Firefox, a session is recorded as a Window if the user closes a window (or a tab that was the last tab in the window), and a Tab if the user closes a tab that wasn't the last tab in its window.

Type

Values of this type are objects. They contain the following properties:

lastModified
number. The time the tab or window was closed, in milliseconds since the epoch.
tabOptional
object. If the object represents a closed tab, then this property is present and will be a tabs.Tab object. This will contain url, title, and favIconUrl only if the extension has the "tabs" permission.
windowOptional
object. If the object represents a closed window, then this property is present and will be a windows.Window object.

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.

ChromeEdgeFirefoxFirefox for AndroidOpera
Basic supportYesNo52 1NoYes
1. 'Tab' objects in Sessions don't contain the 'url', 'title', or 'favIconUrl' properties.

Acknowledgements

This API is based on Chromium's chrome.sessions API.

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:
//
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// 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.
//
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Document Tags and Contributors

Tags: 
  • Add-ons
  • API
  • Extensions
  • Non-standard
  • Reference
  • Session
  • sessions
  • Type
  • WebExtensions
 Contributors to this page: andrewtruongmoz, bsilverberg, wbamberg
 Last updated by: andrewtruongmoz, Jul 13, 2017, 3:20:44 PM
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. browsingData
    6. commands
    7. contextMenus
    8. contextualIdentities
    9. cookies
    10. devtools.inspectedWindow
    11. devtools.network
    12. devtools.panels
    13. downloads
    14. events
    15. extension
    16. extensionTypes
    17. history
    18. i18n
    19. identity
    20. idle
    21. management
    22. notifications
    23. omnibox
    24. pageAction
    25. permissions
    26. privacy
    27. proxy
    28. runtime
    29. sessions
      1. Methods
        1. getRecentlyClosed()
        2. restore()
      2. Properties
        1. MAX_SESSION_RESULTS
      3. Types
        1. Filter
        2. Session
      4. Events
        1. onChanged
    30. sidebarAction
    31. storage
    32. tabs
    33. topSites
    34. types
    35. webNavigation
    36. webRequest
    37. 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. version
    28. 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