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Chapter 1: Introduction to JavaScript
7
ActionScript and Flash
Introduced in Macromedia Flash Player 5, ActionScript was an improvement on a scripting
feature introduced into Flash much earlier. The idea was simply to allow developers to apply custom
movements and behaviors based on user input. It was a full implementation of ECMAScript V1 and
allowed for both procedural and object oriented development styles. Around the time Adobe acquired
Macromedia, ActionScript 2.0 was released, which implemented ECMAScript working draft V4. It was
anticipated that the browser vendors would eventually follow - suit and implement this version also.
Unfortunately, subsequent political disputes between Microsoft and the Mozilla Foundation severely
reduced the likelihood that this version would ever be adopted universally, making Adobe one of the
few vendors likely to ever implement this particular branch of the language. Today, ActionScript is
implemented in both Flash and Flex and has a huge following of professional developers.
Adobe Integrated Runtime (AIR)
Adobe Integrated Runtime (AIR) is a relatively new offering from Adobe, but is already an important
fixture in the programming landscape. It offers cross - platform write - once, run anywhere desktop
development with a special focus on ease of integration with web services. Developers can write
applications in Flex or in HTML with JavaScript that can be compiled to run on OSX, Windows, or Linux
desktops. The HTML / JavaScript implementation is achieved by repackaging a custom version of
Webkit (Safari) with some API extensions to add features like online/offline detection, permanent SQLite
storage, and multimedia support.
In Other Adobe Products
Adobe has also implemented JavaScript as the language used to script and customize products such as
Dreamweaver (for making plugins), Acrobat (for customizing interfaces), and InDesign.
Desktop Widgets
With the popularization of Apple Dashboard widgets, Konfabulator widgets from Yahoo, and
Microsoft Gadgets for Vista, it ’ s now clear that JavaScript is the language of choice for desktop and
dashboard - type gadgets. A widget can be an egg timer, a news reader, or even a simple game. In each of
these cases, widgets can be generally constructed using a combination of JavaScript, CSS, HTML, and/
or XML. Depending on the platform, they may have some limited access to system resources (like the
file system), but generally they run in the context of a very small webpage. Apple Dashboard widgets
have the added capability of using Canvas (graphical) elements because they are rendered using Safari ’ s
browser engine WebKit.
Complementary Technologies
In the world of browser scripting in particular is a set of complementary technologies that developers
must understand. In this book, I will refer to these a great deal and you will develop a thorough
understanding of how they fit into the development stack and how developers can use them in their
applications to build powerful interfaces.
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