7d0a5c0edb
* Adding support for maven assembly plugin to generate executable jar with all dependencies in built * Merge branch 'master' into issue-989 # Conflicts: # abstract-document/pom.xml # pom.xml * Adding maven assemly plugin for projects with name A * Update in format as per checkstyle, i.e. Spcae in place of tab with size of 2 * batch set - 2 having all project with B and C * issue-989 d-e-f * fixing eip pom and adding g-h-i-l-m-n Skipping naked object as it seems it doesn't have main method, will consider this at end * Adding for O and P projects Skipping Object-Mother as we don't have main method for same.
layout, title, folder, permalink, categories, tags
| layout | title | folder | permalink | categories | tags | |
|---|---|---|---|---|---|---|
| pattern | Extension objects | extension-objects | /patterns/extension-objects/ | Behavioral |
|
Intent
Anticipate that an object’s interface needs to be extended in the future. Additional interfaces are defined by extension objects.
Class diagram
Applicability
Use the Extension Objects pattern when:
- you need to support the addition of new or unforeseen interfaces to existing classes and you don't want to impact clients that don't need this new interface. Extension Objects lets you keep related operations together by defining them in a separate class
- a class representing a key abstraction plays different roles for different clients. The number of roles the class can play should be open-ended. There is a need to preserve the key abstraction itself. For example, a customer object is still a customer object even if different subsystems view it differently.
- a class should be extensible with new behavior without subclassing from it.