Flex 3 in Action book excerpt: Advanced reusability in Flex

What is reusability? We use the term loosely to mean ways you can reuse chunks of code either in the same application or across multiple applications. The concept of reusability isn't unique to Flex; each language provides mechanisms to achieve it. The more you're able to reuse, the faster you can develop new applications by leveraging existing code. From a maintenance perspective, you can achieve faster turnaround time when implementing changes. With Flex, reusability can also result in improved performance.

Previous chapters have covered common reusability techniques, including using custom classes and custom components. One of the advanced reusability features is the runtime shared library (RSL). By the end of this chapter, you'll have a strong starting point to understanding what RSLs are as well as Flex's additional reuse capabilities.

A Flex application (which is compiled to a SWF file) can include several kinds of advanced elements: SWC files, RSLs, and modules.

Leveraging these pieces will enable your applications to load quickly and will make them easy to maintain in the long run. You'll learn what each of these elements means for you and how to utilize them in your Flex 3 development.

Pros and cons of a module

This chapter covers the following topics:

• Running shared libraries
• Shared reusability
• The Module API
• Adding patches
• Refactoring

This article is based on Flex 3 in Action, published January 2009. It is being reproduced here by permission from Manning Publications. Manning early access books and ebooks are sold exclusively through Manning. Visit the book's page for more information.

Prerequisites

Knowledge of Flex.

Requirements

In order to make the most of this article, you need the following software and files:

Flex Builder 3

• Try
• Buy

Read the complete chapter

Chapter 18: Advanced reusabiltiy in Flex (PDF, 302KB)

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