CoreLinux++ Functional Requirement Document
Revision $Revision: 1.2 $
Last Modified : Sunday, January 23, 2000

Title : Facade Pattern

Requirement ID: 3145
Analysis References: Use Case Report, Analysis Diagrams
Design References: Class Report, Design Diagrams
Cross References:

1. Introduction

Structuring a system into subsystems helps reduce complexity. A common design goal is to minimize the communication and dependencies between subsystems. A Facade defines a higher-level interface that makes the subsystem easier to use. This is also called a fat interface in some cases, and delegation model.

1.1 Deliverables Overview

The participants in the Facade pattern include:

Facade

Knows which subsystem classes are responsible for a request and delegates client requests to the appropriate subsystem object.

The deliverable is mostly vacuous in that we want to capture the participants abstractions.

The CoreLinux++ team will deliver Facade implementations for specific cases as needed.

Users can utilize the participant abstractions as a basis for creating their own Facade implementation outside of the libcorelinux++ library.

2. Functional Requirements

Facade and participants will be publicly available for extension.

2.1 User Interface Specifications

NA

2.2 Product Services

NA

2.3 External Interfaces and Database Requirements

NA

2.4 Error Handling

NA

2.5 Foreseeable Functional Changes and Enhancements

NA.

3. Non-Functional Requirements

Precondition constraints: None

Postcondition constraints: None

Invarient constraints: None

3.1 Performance Requirements

NA

3.2 User Documentation and Other User Aids

This Document

Analysis Use-Case diagrams

Design class diagrams

3.3 Development Requirements

Standards: CoreLinux++ C++ Standards and Guidelines

Will be part of the libcorelinux++ shared library.

3.4 Foreseeable Non-Functional Changes

NA

4. Remarks and Guidelines for Later Life Cycle Phases

TBD

5. Term Glossary

TBD