Fluent C

Chapter 11. Building a User Management System

This chapter tells the story of applying the patterns from Part I of this book to a running example. With that example, it illustrates how design choices made with the aid of patterns provide benefits and support for programmers. This chapter’s running example is abstracted from an industrial-strength implementation of a user management system.

The Pattern Story

Imagine you are fresh from university and start working for a software development company. Your boss hands you a product specification for a piece of software that stores usernames and passwords and tells you to implement it. The software should provide functionality to check whether a provided password for a user is correct and functionality to create, delete, and view existing users.

You are eager to show your boss that you are a good programmer, but before you even start, your mind fills with questions. Should you write all code into a single file? You know from your studies that this is bad practice, but what’s a good number of files? Which parts of the code will you put into the same files? Should you check the input parameters for each function? Should your functions return detailed error information? At university you learned how to build a software program that works, but you did not learn how to write good code that is maintainable. So what should you do? How do you start?

Data Organization

To answer your questions, start by reviewing the patterns in this book ...