O’Reilly: Inside RIA

Having covered the finer points of installing Flex Builder last time, both in it's standalone form and as a plugin, we'll now focus on making sense of the work environment within Flex Builder. Novice Flex users should expect to take away from this article an understanding of the organizational structure of the Flex development environment within Flex Builder 3, as well as an appreciation for the power of the Flex Builder workbench.

It's likely that if you're interested in learning about Flex, you've already downloaded and experimented with Flex Builder 3. In the next few posts we'll be exploring Flex Builder. We'll start with the installation, and then go into more depth as we explain how the premiere tool for building Flex applications works. We've already made mention of the fact that Flex Builder is based on Eclipse, and we'll be discussing this useful tool as well.

Organizing data into chunks is a fundamental part of our cognitive experience. The ability to understand individual items in terms of their membership within a group saves our brains an immense amount of processing power. Imagine the difficult time you'd have if, when you went to the grocery store, all of the things you needed to pick up were written on separate pieces of paper instead of on a nicely organized list. You could still get your shopping done, but it would be a real pain to shuffle through all those individual sheets! In addition, you'd have to make sure that all of those sheets really actually contained things you needed to pick up from the store, and not perhaps, things that you already had in your refrigerator. In other words, using an organized system that groups items together into meaningful lists saves you a lot of time and effort.

In order for software to be useful, it needs to be able to react to its environment. Put another way, a program needs to have logic. The logic of an application gives it the ability to change course when a given condition is met. Program flow in ActionScript 3.0 is controlled by conditionals and loops. Both conditionals and loops are responsible for determining whether a particular code block is executed, and are therefore placed within a method body. The main difference between the two is that conditionals decide on executing one collection of statements over another, and loops allow a collection of statements to execute over and over. As we'll soon see, loops, like many things in object-oriented programming, are great tools that provide the very important element of scalability. But first, a bit about conditionals.

As promised, the current installment of Learning Flex From Scratch focuses on the syntax of ActionScript 3.0. We know from the previous post that an application written in an object-oriented programming language involves, by definition, the use of objects. Objects, we found out, are derived from classes, which serve as a blueprint for the object's methods and properties. This post goes into the details of creating a class in ActionScript 3.0, providing a foundation for our journey into the language. The code examples provided here are strictly theoretical, and shouldn't be thought of as a working piece of software, but rather as a starting point to illustrate some basic language concepts.

As we have previously mentioned, Flex 3 makes use of ActionScript 3.0, a powerful object-oriented programming language. Before we dive into the specific syntax used in ActionScript, let's take a look at what makes a language object-oriented in the first place, and the benefits to using and object-oriented language versus a procedural language.

In this post we take a deeper look at what Flex is and what it can do. Our goal is to provide a clear picture of the environment in which you use Flex to create Rich Internet Applications (RIAs). Fist, let's have a quick discussion about the nature of RIAs so that we can understand why we would want to use Flex in the first place.

The "Learning Flex From Scratch" series written by Adam Flater and Scott Sheridan, aims to help not only a Flex novice, but also a programming novice jump into the world of creating Rich Internet Applications using Flex. The installments of the series will cover everything from installing the Flex Builder I.D.E., to some background information on object-oriented programming. You'll even get to learn about advanced topics like source control and design patterns (a la Cairngorm) from the perspective of a beginner.