Visitor
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==Description== | ==Description== | ||
− | The Visitor describes three | + | The Visitor describes three distinct components: |
*Object Structure: Provides a visitor with access to its elements | *Object Structure: Provides a visitor with access to its elements | ||
*Element: Accepts visits | *Element: Accepts visits | ||
*Visitor: Accesses an element to perform operations | *Visitor: Accesses an element to perform operations | ||
− | + | Figure 1 graphically describes these Visitor pattern interactions. | |
− | [[image:Visitor.JPG|frame|centre|A UML class diagram representing the Visitor structure]] | + | [[image:Visitor.JPG|frame|centre|'''Figure 1: A UML class diagram representing the Visitor structure''']] |
Revision as of 12:21, 30 July 2008
Introduction
The Visitor is a behavioural pattern. It allows the designer to define new operations on an object structure and its elements, without modifying the object structure itself.
Description
The Visitor describes three distinct components:
- Object Structure: Provides a visitor with access to its elements
- Element: Accepts visits
- Visitor: Accesses an element to perform operations
Figure 1 graphically describes these Visitor pattern interactions.