MXML

Definition

MXML is an XML-based user interface markup language. MXML is considered a proprietary standard due to its tight integration with Adobe technologies, in particular Flash.

The Adobe Flex developer kit can be use to compile MXML + ActionScript code into Flash. It's a fairly popular technology for developping rich internet applications (e.g. educational multimedia).

This entry is part of the ActionScript and Flash series of articles.

Introductory example

A Flex program is a text file that contains a combination of xml elements and optionally actionscript instructions.

A basic mxml document would look something like this:

File myFirstApplication.mxml :

<?xml version="1.0" encoding="utf-8"?>

<mx:Application 
    xmlns:mx="http://www.adobe.com/2006/mxml" 
    horizontalAlign="center" verticalAlign="middle" 
    width="300" height="160" 
>
    <mx:Panel 
        paddingTop="10" paddingBottom="10" paddingLeft="10" paddingRight="10"
        title="My First Application"  
    >

        <mx:Label text="Hello World!" fontWeight="bold" fontSize="24"/>
    </mx:Panel>
</mx:Application>

Make sur to respect XML Syntax (e.g. closing tags).

Put the text above in a text file. Save the text file as "myFirstApplication.mxml". Assuming the Flex framework is properly installed, in the terminal, type

mxmlc myFirstApplication.mxml

Information appears on the screen and about half a second later, if all is well, you get informed that a file "myFirstApplication.swf" has been produced. Open this file in a flash player or in a web browser.

SWF files generated by Flex require Flash Player 9 or above.

Links

• Flex Developer Center has a lot of information. Not always obvious to find the best entry point for beginners, but have a look at these (if the links didn't move ...):
  • Coding with MXML and ActionScript
  • Building components in MXML
  • Flex Programming Elements (A manual chapter).

• MXML (Not very useful as of Aug. 2008)

• An overview of MXML: The Flex markup language by C. Coenraets, Adobe (2004). Outdated, but still useful !