Apache Flex Overview, updated

crazy with the books (Photo credit: leff)

What is Flex? 

Flex is a highly productive, free open source framework that provides enterprise-level components for Flash Platform for designing, building and maintaining expressive mobile, web and desktop applications that deploy consistently on all major devices, browsers, desktops, and operating systems.

Flex allows you to build web and mobile applications that share a common code base, reducing the time and cost of application creation and longer term maintenance.

Flex Overview

Adobe has donated the Flex SDK to Apache Software foundation. [Adobe Donating Flex to Open Source Foundation (infoq.com)]

• Flex 3 Getting Started - Animated Overview on Adobe Learning Resource 
• Flex 4 Getting Started - Getting Started page for Flex 4 (current release) on the Flex Developer Center.

What is Adobe Flash Builder ?

Adobe^® Flash^® Builder^™ 4.5 software (formerly Adobe Flex^® Builder^™) is an Eclipse^™ based development tool for rapidly building expressive applications for the following platforms:

1. mobile, 
2. web, and
3. desktop

using the following technologies:

1. ActionScript^® and MXML
2. the open source Flex framework. 

Adobe Flash Builder 4.5 introduces new support for mobile application development and testing that enables use of a common code base to build apps for the following platforms: 

1. Android^™,
2. BlackBerry^® Tablet OS, and
3. iOS mobile platforms 

while sharing code from web applications. It includes support for the following features: 

• intelligent coding, 
• interactive step-though debugging, 
• application profiling, and 
• visual design of the user interface layout.

Can I learn Apache Flex (previously Adobe Flex) ?

Below are the Prerequisites for learning Adobe Flex includes basic understanding of following topics:

• Basic understanding of any programming Language ( for e.g. C#, Java, C / C++ etc..)
• HTML (Hyper Text Markup Language)
• XML (eXtensible Markup Language)
• JSON (JavaScript Object Notation)
• CSS (Cascading Style Sheets)
• Exposure to any server side technology (like ColdFusion, Java Servlet/JavaServer Pages, PHP, .NET) is recommended but not necessary. 

Which languages does Flex Framework supports ?

A Flex application consists primarily of code written in two different languages

• ActionScript - a fully object oriented, strictly typed, ECMA Script language. It is is used for describing the event handlers and custom application logic.
• MXML - an XML based markup language. It is used to provide description of the appearance  and components that make up the application.

What is Flash Catalyst ?

An additional product Adobe® Flash® Catalyst™ (code-named Thermo)  a professional interaction design tool for designers to create complex RIA user interfaces and interactions by using a visual editor which will create Flex application code that the designer and developer can share. Adobe Flash Catalyst is a tool for rapidly creating user interfaces without coding.

Future of Flash Catalyst & Flash Builders

Following the decision of Flex moving to the Apache Foundation, that Flash Catalyst will be discontinued. Flash Builder will also have features the following features removed in future:

• Design View,
• Data Centric Development (DCD)
• and Flash Catalyst workflows. 

Adobe has stopped sales and development of Flash Catalyst tool, Adobe is now focusing mainly on creating tools for native applications using AIR and HTML5 for e.g. 

1. Adobe Muse (http://muse.adobe.com)
2. Adobe & HTML (http://html.adobe.com/)

As an alternate to Flash Catalyst it is recommended to use Adobe Creative Suite Master Collection. (refer http://www.adobe.com/in/products/flashcatalyst.html for details)

Further Reading:

• Future of Flash and Flex
• Life After Adobe Flash Builder(drdobbs.com) - Developing Flex with using Microsoft's Visual Studios IDE

Learning Resources:

• Flex 3 LiveDocs - Flex Help Documentation
• Tour de Flex - A desktop application for exploring Flex capabilities
• Flex Developer Center - collection of resources on flex
• flex.apache.org - Apache Flex website
• Flex Showcase - list of desktop and mobile applications written in Flex
• Flex Cookbook - collection of solution to common problems

Related articles:

• Talking about: Flex Gumbo (Flex 4) - new features (psyked.co.uk) - Flex 4 was codenamed Gumbo

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• FlexJS: Flex for HTML/JS/CSS(flexcloset.wordpress.com) - A next generation flex sdk that cross compiles MXML & ActionScript into HTML, JS and CSS.

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• Apache Flex 4.11 Released!(blogs.apache.org)

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• How is Flex Doing? Quick Start Guides and Tutorials(jetbrains.com)

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• Flash Platform Rundown - Week of October 27th, 2013(inflagrantedelicto.memoryspiral.com)

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• Alex's Flex Closet Lives On!(flexcloset.wordpress.com) - yet another blog about flex.

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• Thumbs Up for Apache Flex(robsondesign.com) - success story about migration from Adobe Flex 4.5.1 SDK to Apache Flex 4.10.1 SDK.

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• Flash Platform Rundown - Week of October 20th, 2013(inflagrantedelicto.memoryspiral.com)

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