Flash movies are known for their small file size and fast download. The movie file itself is compressed, external graphics and sound elements are also often heavily compressed using for example jpeg and mp3. XML files loaded into a Flash movie however are not. This is not a big problem most of the time, but it could be. I will explain one simple way to reduce the file size of XML files to about 30-50% of the original size (in some extreme cases you can reduce them to about 10% of the original file size). If you have a lot of XML files, this could save quite a bit of bandwidth.

The XML file is compressed using a variation of the LZ77 algorithm. This method is pretty effective and is very fast to decode (which is good since we are dealing with Flash). The encoding is quite CPU intensive though, and it is not ideally done using Action Script. The Flash XML Compressor is therefore available as a separate program (Windows executable).

XML is the extensible markup language. XML uses tags very similar to HTML, instead of describing the structure of the page the tags, XML uses the tags to describe the data. This allows a structured data format that can be extended without breaking previous implementations. A good starting point for learning XML is:

XML is becoming a standard way for people to export and import data from different systems. It's simplified mark up language make it easy for different systems to read data in, without knowing the exact structure of the data. If the XML data description has been properly created it is possible to add additional information to your XML data files without affecting system that is already using the information. If you load XML data into flash, an object model will be created that will allow you to easily manipulate and extract the data. The same object model is available to create XML data, and export it to an external system.

For retrieving information external to the flash file load variables might work when loading simple or small amounts of information. Once you have to retrieve information where the amount of information changes, or is being created by an external source, you should use XML Flash and XML shows designers and developers how to integrate these powerful technologies and create dynamic web sites. Empower your Flash projects with dynamic content, backend databases, server-based applications, peer-to-peer, and more.