var aURL = "chrome://myext/mytab.xul";
let tabmail = getMail3Pane().document.getElementById("tabmail");
tabmail.openTab("chromeTab", { chromePage: aUrl });
See also
- WebExtensions
- Getting started
- Guides
- JavaScript APIs
- Manifest keys
- Add-on SDK
- Getting started
- High-Level APIs
- Low-Level APIs
- /loader
- chrome
- console/plain-text
- console/traceback
- content/content
- content/loader
- content/mod
- content/symbiont
- content/worker
- core/heritage
- core/namespace
- core/promise
- dev/panel
- event/core
- event/target
- frame/hidden-frame
- frame/utils
- fs/path
- io/byte-streams
- io/file
- io/text-streams
- lang/functional
- lang/type
- loader/cuddlefish
- loader/sandbox
- net/url
- net/xhr
- places/bookmarks
- places/favicon
- places/history
- platform/xpcom
- preferences/event-target
- preferences/service
- remote/child
- remote/parent
- stylesheet/style
- stylesheet/utils
- system/child_process
- system/environment
- system/events
- system/runtime
- system/unload
- system/xul-app
- tabs/utils
- test/assert
- test/harness
- test/httpd
- test/runner
- test/utils
- ui/button/action
- ui/button/toggle
- ui/frame
- ui/id
- ui/sidebar
- ui/toolbar
- util/array
- util/collection
- util/deprecate
- util/list
- util/match-pattern
- util/object
- util/uuid
- window/utils
- Firefox for Android
- Getting started
- APIs
- Legacy
- Restartless extensions
- Overlay extensions
- Themes
- Lightweight themes
- Complete themes
- Publishing add-ons
- Guides
- Community and support
- Channels