Changes in Thunderbird 84

compose

The beginNew function now has an optional messageId argument. If messageId is provided, the referenced message is opened to compose as a new message. This works for ordinary messages and templates.

This change has been backported to Thunderbird 78.7.0.
Using beginForward function with a forwardInline type and details argument specified has been fixed.

This change has been backported to Thunderbird 78.7.0.

The standard properties available to onShown are now available for messages being composed, if your extension has the compose permission.

This change has been backported to Thunderbird 78.6.0.

At start-up, tabs.create will now wait for a window to open before attempting to open a tab.

This change has been backported to Thunderbird 78.5.0.

The openDefaultBrowser(url) function has been added.

This change has been backported to Thunderbird 78.6.0.

The setLabel(details) and getLabel(details) functions have been added. It is now possible to set a label value different from the title (which is used as tooltip text). The label can be set to an empty string to make the action button not have a label at all. If the toolbar is set to text-mode only (no icons), the action button label uses the title as fallback, in case an empty label has been set.

This change has been backported to Thunderbird 78.6.0.

The setLabel(details) and getLabel(details) functions have been added. It is now possible to set a label value different from the title (which is used as tooltip text). The label can be set to an empty string to make the action button not have a label at all. If the toolbar is set to text-mode only (no icons), the action button label uses the title as fallback, in case an empty label has been set.

This change has been backported to Thunderbird 78.6.0.

The setLabel(details) and getLabel(details) functions have been added. It is now possible to set a label value different from the title (which is used as tooltip text). The label can be set to an empty string to make the action button not have a label at all. If the toolbar is set to text-mode only (no icons), the action button label uses the title as fallback, in case an empty label has been set.

This change has been backported to Thunderbird 78.6.0.

Bugzilla list of fixed WebExtension API defects in Thunderbird 84.