unload module allows modules to register callbacks that are called
when they are unloaded.
ensure() on an object does two things:
- It replaces a destructor method with a wrapper method that will never call the destructor more than once.
- It ensures that this wrapper method is called when the object's module is unloaded.
Therefore, when you register an object with
ensure(), you can call its
destructor method yourself, you can let it happen for you, or you can do both.
The destructor will be called with a single argument describing the reason
for the unload; see
object does not have the expected
destructor method, then an exception is thrown when
ensure() is called.
An object that defines a destructor method.
Optional name of the destructor method. Default is
Registers a function to be called when the module is unloaded.
A function that will be called when the module is unloaded. It is called
with a single argument, one of the following strings describing the reason
"downgrade". If a reason could not be determined,
undefined will be
Note that if an add-on is unloaded with reason
"disable", it will not be
"uninstall" while it is disabled. See