Add-ons using the techniques described in this document are considered a legacy technology in Firefox. Don't use these techniques to develop new add-ons. Use WebExtensions instead. If you maintain an add-on which uses the techniques described here, consider migrating it to use WebExtensions.
From Firefox 53 onwards, no new legacy add-ons will be accepted on addons.mozilla.org (AMO).
From Firefox 57 onwards, WebExtensions will be the only supported extension type, and Firefox will not load other types.
Even before Firefox 57, changes coming up in the Firefox platform will break many legacy extensions. These changes include multiprocess Firefox (e10s), sandboxing, and multiple content processes. Legacy extensions that are affected by these changes should migrate to WebExtensions if they can. See the "Compatibility Milestones" document for more.
A wiki page containing resources, migration paths, office hours, and more, is available to help developers transition to the new technologies.
AddonListeners can be registered with addAddonListener() and will then receive notification of changes to the add-ons currently installed. These notifications come in the form of calls to methods on the listener object. A listener only needs to implement the methods corresponding to the events it cares about; missing methods will not cause any problems.
Method Overview
void onEnabling(in Addon addon, in boolean needsRestart) |
void onEnabled(in Addon addon) |
void onDisabling(in Addon addon, in boolean needsRestart) |
void onDisabled(in Addon addon) |
void onInstalling(in Addon addon, in boolean needsRestart) |
void onInstalled(in Addon addon) |
void onUninstalling(in Addon addon, in boolean needsRestart) |
void onUninstalled(in Addon addon) |
void onOperationCancelled(in Addon addon) |
void onPropertyChanged(in Addon addon, in string properties[]) |
Methods
onEnabling()
Called when an add-on is about to be enabled.
void onEnabling(
in Addon addon,
in boolean needsRestart
)
Parameters
- addon
- The
Addonthat is being enabled - needsRestart
- True if an application restart is necessary for the change to take effect
onEnabled()
Called when an add-on has been enabled.
void onEnabled(
in Addon addon,
)
Parameters
- addon
- The
Addonthat has been enabled
onDisabling()
Called when an add-on is about to be disabled.
void onDisabling(
in Addon addon,
in boolean needsRestart
)
Parameters
- addon
- The
Addonthat is being disabled - needsRestart
- True if an application restart is necessary for the change to take effect
onDisabled()
Called when an add-on has been disabled.
void onDisabled(
in Addon addon,
)
Parameters
- addon
- The
Addonthat has been disabled
onInstalling()
Called when an add-on is about to be installed.
void onInstalling(
in Addon addon,
in boolean needsRestart
)
Parameters
- addon
- The
Addonthat is being installed - needsRestart
- True if an application restart is necessary for the change to take effect
onInstalled()
Called when an add-on has been installed.
void onInstalled(
in Addon addon,
)
Parameters
- addon
- The
Addonthat has been installed
onUninstalling()
Called when an add-on is about to be uninstalled.
void onUninstalling(
in Addon addon,
in boolean needsRestart
)
Parameters
- addon
- The
Addonthat is being uninstalled - needsRestart
- True if an application restart is necessary for the change to take effect
onUninstalled()
Called when an add-on has been uninstalled.
void onUninstalled(
in Addon addon,
)
Parameters
- addon
- The
Addonthat has been uninstalled
onOperationCancelled()
Called when a pending operation for an add-on is cancelled.
void onOperationCancelled(
in Addon addon,
)
Parameters
- addon
- The
Addonthat has had a pending operation cancelled
onPropertyChanged()
Called when one or more properties of Addon has changed.
Only applies to the following properties:
- applyBackgroundUpdates
void onPropertyChanged(
in Addon addon,
in string properties[]
)
Parameters
- addon
- The
Addonthat has had its properties changed - properties
- An array of the names of properties that changed.