12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > A Flexible Approach for Instance Adaptation Dur...
View graph of relations

« Back

A Flexible Approach for Instance Adaptation During Class Versioning

Research output: Contribution in Book/Report/ProceedingsPaper

Published

Publication date2001
Host publicationObjects and Databases International Symposium Sophia Antipolis,France,June 13,2000 Revised Papers
EditorsKlaus Dittrich, Giovanna Guerrini, Isabella Merlo, Marta Oliva, M. Elena Rodriguez
Place of publicationBerlin
PublisherSpringer
Pages101-113
Number of pages13
ISBN (Print)978-3-540-41664-7
Original languageEnglish

Publication series

NameLecture Notes in Computer Science
PublisherSpringer
Volume1944
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Abstract

One of the consequences of evolution can be the inability to access objects created using the older schema definition under the new definition and vice versa. Instance adaptation is the conversion of objects to a compatible definition or making objects exhibit a compatible interface. Existing evolution approaches are committed to a particular instance adaptation strategy. This is because changes to the instance adaptation strategy or an attempt to adopt an entirely different strategy would be very costly. This paper proposes a flexible instance adaptation approach for systems employing class versioning to manage evolution. Flexibility is achieved by encapsulating the instance adaptation code in aspects - abstractions introduced by aspect-oriented programming to localise cross-cutting concerns. This makes it possible to make cost-effective changes to the instance adaptation strategy. The flexibility of the approach is demonstrated by using two instance adaptation strategies: error handlers and update/backdate methods.