Adobe Flex

                                                                          -Ganesh
Overview:

Traditional application programmers found it challenging to adapt to the animation metaphor upon which the Flash Platform was originally designed. Flex seeks to minimize this problem by providing a workflow and programming model that is familiar to these developers. MXML an XML-based markup language, offers a way to build and lay out graphic user interfaces. Interactivity is achieved through the use of ActionScript, the core language of Flash Player that is based on the ECMAScript standard.

The Flex SDK comes with a set of user interface components including buttons, list boxes, trees, data grids, several text controls, and various layout containers. Charts and graphs are available as an add-on. Other features like web services, drag and drop, modal dialogs, animation effects, application states, form validation, and other interactions round out the application framework.

In a multitiered model, Flex applications serve as the presentation tier. Unlike page-based HTML applications, Flex applications provide a stateful client where significant changes to the view don't require loading a new page. Similarly, Flex and Flash Player provide many useful ways to send and load data to and from server-side components without requiring the client to reload the view. Though this functionality offered advantages over HTML and JavaScript development in the past, the increased support for XMLHttpRequest in major browsers has made asynchronous data loading a common practice in HTML-based development as well.

Technologies that are commonly compared to Flex include Curl, OpenLaszlo, Ajax, XUL, JavaFX, and Windows Presentation Foundation technologies such as Silver light.

Although popular as a rich internet application development environment, Flex is not without its detractors. In February, 2009, analyst firm CMS Watch criticized the use of Flex for enterprise application user interfaces.

Create engaging, cross-platform rich Internet applications

Flex is a highly productive, free open source framework for building and maintaining expressive web applications that deploy consistently on all major browsers, desktops, and operating systems. While Flex applications can be built using only the free open source framework, developers can use Adobe® Flex® Builder™ software to dramatically accelerate development.


Application Development Process

• Define an application interface using a set of pre-defined components (forms, buttons, and so on)

• Arrange components into a user interface design

• Use styles and themes to define the visual design

• Add dynamic behavior (one part of the application interacting with another, for example)

• Define and connect to data services as needed

• Build the source code into an SWF file that runs in the Flash Player

Some of the versions:

Macromedia Flex Server 1.0 and 1.5

Macromedia targeted the enterprise application development market with its initial releases of Flex 1.0 and 1.5. The company offered the technology at a price around US$15000 per CPU. Required for deployment, the Java EE application server compiled MXML and ActionScript on-the-fly into Flash applications (binary SWF files). Each server license included 5 licenses for the Flex Builder IDE.

Adobe Flex 2

Adobe significantly changed the licensing model for the Flex product line with the release of Flex 2. The core Flex 2 SDK, consisting of the command-line compilers and the complete class library of user interface components and utilities, was made available as a free download. Complete Flex applications can be built and deployed with only the Flex 2 SDK, which contains no limitations or restrictions compared to the same SDK included with the Flex Builder IDE.

Adobe based the new version of Flex Builder on the open source Eclipse platform. The company released two versions of Flex Builder 2, Standard and Professional. The Professional version includes the Flex Charting Components library.

Enterprise-oriented services remain available through Flex Data Services 2. This server component provides data synchronization, data push, publish-subscribe and automated testing. Unlike Flex 1.0 and 1.5, Flex Data Services is not required for the deployment of Flex applications.

Coinciding with the release of Flex 2, Adobe introduced a new version of the ActionScript programming language, known as Actionscript 3, reflecting the latest ECMAScript specification. The use of ActionScript 3 and Flex 2 requires version 9 or later of the Flash Player runtime. Flash Player 9 incorporated a new and more robust virtual machine for running the new ActionScript 3.

Flex was the first Macromedia product to be re-branded under the Adobe name...

Adobe Flex 3

On April 26, 2007 Adobe announced their intent to release the Flex 3 SDK (which excludes the Flex Builder IDE and the LiveCycle Data Services) under the terms of the Mozilla Public License. Adobe released the first beta of Flex 3, codenamed Moxie, in June 2007. Major enhancements include integration with the new versions of Adobe's Creative Suite products, support for AIR (Adobe's new desktop application runtime), and the addition of profiling and refactoring tools to the Flex Builder IDE.

• In October 2007, Adobe released the second beta of Flex 3.

• On December 12, 2007, Adobe released the third beta of Flex 3.

• On February 25, 2008, Adobe released Flex 3 and ADOBE AIR 1.0.

Adobe Flash Builder 4

Adobe has announced that Flex 4.0 (code named Gumbo) will be released in early 2010.The Flex 4 development tool will be called Adobe Flash Builder,] formerly known as Adobe Flex Builder.

Some themes that have been mentioned by Adobe that will be incorporated into Flex 4 are as follows:

• Design in Mind: The framework will be designed for continuous collaboration between designers and developers.

• Accelerated Development: Be able to take application development from conception to reality quickly.

• Horizontal Platform Improvements: Compiler performance, language enhancements, BiDi components, enhanced text. (Speculation derived from Adobe Systems)

• Full Support for Adobe Flash Player 10.

• Broadening Horizons: Finding ways to make a framework lighter, supporting more deployment runtimes, runtime MXML. (Speculation derived from Adobe Systems)

Related tools:

Adobe Flash Catalyst

On October 2, 2007, Adobe announced a new design tool related to Flex codenamed Adobe Thermo. On November 17, 2008 Adobe announced the official name of the product would be Adobe Flash Catalyst.

LiveCycle Data Services

Main article: Flex Data Services

LiveCycle Data Services (previously called Flex Data Services) is a server-side complement to the main Flex SDK and Flex Builder IDE and is part of a family of server-based products available from Adobe. Deployed as a Java EE application, LiveCycle Data Services adds the following capabilities to flex applications:

• Remoting, which allows Flex client applications to invoke methods on Java server objects directly. Similar to Java remote method invocation (RMI), remoting handles data marshalling automatically and uses a binary data transfer format.

• Messaging, which provides the "publish" end of the "publish/subscribe" design pattern. The Flash client can publish events to a topic defined on the server, subscribe to events broadcast from the message service. One of the common use cases for this is real-time streaming of data, such as financial data or system status information.

• Data management services, which provides a programming model for automatically managing data sets that have been downloaded to the Flex client. Once data is loaded from the server, changes are automatically tracked and can be synchronized with the server at the request of the application. Clients are also notified if changes to the data set are made on the server.

• PDF document generation, providing APIs for generating PDF documents by merging client data or graphics with templates stored on the server.

BlazeDS

Previously available only as part of Adobe LiveCycle Data Services ES, Adobe plans to contribute the BlazeDS technologies to the community under the LGPL v3. BlazeDS gives Adobe developers free access to the remoting and messaging technologies developed by Adobe.

Concurrent with this pre-release of BlazeDS, Adobe is publishing the AMF binary data protocol specification, on which the BlazeDS remoting implementation is based, and is attempting to partner with the community to make this protocol available for major server platforms.

Flex and ColdFusion

Flex 2 offers special integration with ColdFusion MX 7. The ColdFusion MX 7.0.2 release adds updated Flash Remoting to support ActionScript 3, a Flex Data Services event gateway, and the Flex Data Services assembler. Flex Builder 2 also adds extensions for ColdFusion providing a set of wizards for RAD Flex development. A subset of Flex 1.5 is also embedded into ColdFusion MX 7 middleware platform, for use in the ColdFusion Flash forms feature. It is possible to use this framework to write rich internet applications, although its intended purpose is for rich forms only.