Developing A Flex Application

By Author: Gary Klingsheim
Total Articles: 4762
Comment this article

Flex is a powerful tool for developing rich internet applications but for beginners, Flex may be a bit overwhelming. Perhaps you understand the basics of Flex and what it can do for you, namely some of the beneficial features like cross compatibility, but you lack a concrete understanding of the ins-and-outs of the platform. This article will suggest some methods for familiarizing yourself with Flex as well as methods for laying out applications, making code changes, repeating components, and managing data.

Sample Applications are Great Learning Tools
Unless you're an expert, you might find it beneficial to do some practice with Flex before you start developing applications. There are a number of sample applications that you can manipulate in order to familiarize yourself with Flex and exactly what it can do. Flex can be utilized to create simple applications that feature the basic building blocks of application development, but also gives developers the power to create complex, interactive applications. Many of the major features in flex can be surveyed using Flex Explorer. Quickly learn about these major ...
... features as well as the kind of control that Flex gives to developers.

Using Containers and Controls to Lay out Applications
In simpler terms, containers are the components of a user interface that allow you to control the layout of your application. Child sizing, positioning, and navigation are examples of features that are controlled by containers. Buttons, Text Area, and Combo Boxes are examples of controls that are components of the user interface. MXML tags are used to bring containers and controls to your application but developers can also use ActionScript to add them at runtime.

Enhancing Performance with Code Changes
There are a number of facts that developers should consider when creating their applications. The smooth operation of applications is vital to their success and as such understanding code changes can be crucial for enhancing performance. For example, start up times for applications are slowed drastically when you have too many levels of nested containers. Similarly, applications can be slowed by Macromedia Flash Debut Player and by the use of trace statements. Slowed performance is a considerable annoyance to the end user and as such you should always be sure to test your application in both Flash Player and Flash Debug Player to ensure smooth running.
A container's creation policy property can help you determine when you should create components at runtime. Applications can create components at various stages: at start up, when users navigate to a container, or even because of user interaction. Therefore, you should configure an application so that it is laid out incrementally at start up. Likewise, the position, width, and height of components are customizable so that start up time can be enhanced. Moreover, performance can be improved with the Grid container but only when controls are required to line up horizontally and vertically. As you can see, the developer has a number of tools and resources to improve performance at every stage of the development process.

Repeating Components
Developers are always looking for the best way to dynamically repeat components. In Flex, you have a choice between the Repeater object, Horizontal List, Tile List, or List control. Better performance can be achieved by replacing layouts as is appropriate. For example, during the Flex 1.0 timeframe, you can replace layouts created using Repeater with a combination of a Horizontal List or Tile List and a cell renderer.
If you want to repeat a small number of simple user interface components, you can use the Repeater object. Examples of this layout include Radio Button controls or other controls that are used in Form containers. On the other hand, if you want to display more than a few repeated objects, you can use the Horizontal List, Tile List or List control.
To display data horizontally, much like an HBox container, you can use the Horizontal List. Items are always displayed from left to right when using the Horizontal List while the Tile List displays items in a tile layout, as you would expect from the Tile container. Therefore, Tile List provides the direction property that decides whether the next item is down or to the right. The List displays items in a single column and all these controls, Horizontal List, Tile List, and List, instantiate all objects that can be seen in the list.

Data Management
Finally, Flex provides a number of resources and tools for managing data. Using MXML tags you have a number of options for data management. You can send data to server-side data sources using HTTP Post and GET commands, Java objects or other web services. You can also receive data from these server-side data sources and even share data between client-side items in your application. Furthermore, data can easily be stored in client-side objects. Moreover, data can be manipulated before it is used or displayed; for example, you can format data before it is displayed in the user interface and you can validate your data before it is used as well.

As one of the most versatile developer platforms, Flex has quite the reputation to live up to. Developers choose Flex because of the range of control they experience and also because of the design and style elements of Flex. Whether you're looking to build a very simple application or you want to create a uniquely rich internet application that features all the bells and whistles of modern RIA, Flex gives you the tools you need.
About Author:
Moonrise Productions is a full services San Francisco web design company. They offer complete design services, social network web development, ecommerce development, social network hosting and more. With New York, San Diego, San Francisco and a Los Angeles presence no matter where you are, we've got people to serve you.