# `RowDestroySignal`

#### Called before an instance is deleted. Sender is the instance's class. Arguments are `(instance, post_funcs)`.

The RowDestroySignal class is accessible via the `sqlobject.events` module.

`post_funcs` is a list of callbacks, intended to have functions appended to it, and are called with arguments `(instance)`. If any of the post_funcs raises an exception, the deletion is only affected if this will prevent a commit.

You cannot cancel the delete, but you can raise an exception (which will probably cancel the delete, but also cause an uncaught exception if not expected).

Note: this is not called when an instance is destroyed through garbage collection.

@@: Should this allow `instance` to be a primary key, so that a row can be deleted without first fetching it?

## Methods

#### f `__sizeof__(...)` ...

__sizeof__() -> int size of object in memory, in bytes

#### f `__format__(...)` ...

default object formatter

#### f `__subclasshook__(...)` ...

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

#### f `__init__(...)` ...

x.__init__(...) initializes x; see help(type(x)) for signature

See the source for more information.