CSC/ECE 517 Fall 2010/ch7 7b vk

Information Expert Pattern

Information Expert Pattern is one of the GRASP patterns or principles used as a mental aid to help assigning responsibilities to various software classes, in the process of design of object oriented software.

Introduction

Object oriented design is a process of building a system of interacting objects to solve a given software problem.It can be otherwise defined as,identifying requirements and creating a domain model, then adding methods to the software classes, and defining the messaging between the objects to fulfill the requirements. But, deciding what methods belong where, and how the objects should interact, is critically important in the designing process and is something non-trivial.

Experienced Object-oriented developers build up a repertoire of both general principles and idiomatic solutions that guide them in creation of software. The principles and idioms, if codified in a structured format describing the problem and solution, and given a name, may be called as patterns.

General Responsibility Assignment Software Patterns(or Principles) , popularly known as GRASP, are a set of guidelines for assigning responsibility to software classes and objects in object oriented design. Information Expert Pattern is first among the basic five GRASP Patterns, Information Expert, Creator, High Cohesion, Low Coupling and Controller, which address very basic, common questions and fundamental design issues.