Essence


By: A. Carlson

Many classes, particularly persistent ones, require that a certain subset of their attributes be valid before an instance can be considered valid. How can this be guaranteed in component-based or distributed environments where the client that creates the instances is outside your design control? Use an essence object for the compulsory properties of the object being created--the CreationTarget. There should be an essence class for each CreationTarget class.

Published in: PLoPD4
Pages: 33-40
Category: Distributed Systems, Fault-Tolerant Systems

Summary: Many classes, particularly persistent ones, require that a certain subset of their attributes be valid before an instance can be considered valid. How can this be guaranteed in component-based or distributed environments where the client that creates the instances is outside your design control? Use an essence object for the compulsory properties of the object being created--the CreationTarget. There should be an essence class for each CreationTarget class.