class AttributeEvent(object):
A token propagated throughout the course of a chain of attribute events.
Serves as an indicator of the source of the event and also provides a means of controlling propagation across a chain of attribute operations.
The .Event object is sent as the initiator argument
when dealing with events such as .AttributeEvents.append,
.AttributeEvents.set,
and .AttributeEvents.remove.
The .Event object is currently interpreted by the backref
event handlers, and is used to control the propagation of operations
across two mutually-dependent attributes.
| Unknown Field: attribute | |
| impl | The .AttributeImpl which is the current event
initiator. |
| op | The symbol .OP_APPEND, .OP_REMOVE,
.OP_REPLACE, or .OP_BULK_REPLACE, indicating the
source operation. |