XFL, the New File Format for Flash CS4
via Colin Moock
For a couple years now a trend has been developing in the realm of document file formats. Software producers are moving away from using fully binary formats for their document files, which are inherently obfuscated. For instance, Microsoft Office document formats for Word, Excel, and PowerPoint have moved away from having their contents – text, graphics, and otherwise – totally embedded in a single file, and are instead (starting at the Office 2007 version) wrapped in a compressed ZIP file. You can see what I mean by changing the extension of a Word .docx file to .zip and opening the resultant file. Inside you’ll find the pieces and parts of the document readily accessible, including an XML file that describes the structure of the content and any graphic files that have been included.
Adobe has joined the movement toward file format transparency. Of interest to Flash developers is the upcoming XFL file format to be used in Flash CS4, which is a .zip formatted document containing an XML file describing the structure of the Flash document along with a folder containing graphics, sounds, and other assets.
The .fla format that Flash CS3 and below use does not have an open specification, which has made it very difficult (read: impossible) for third-parties to develop tools for importing and exporting .fla files. However, since the XFL format will have a publicly available spec, doors will be open for exciting developments in the open-source (and possibly otherwise) communities. Imagine being able to readily interchange source to and from Flash with Adobe and non-Adobe software. Scenarios like third-party code editors that have direct access to assets in the Flash Library, more specialized animation and audio synchronizing applications, and perhaps further down the line, flipping quickly between using your favorite 3D modeling software to set up inverse kinematics in a Collada object and Flash to wire up interaction events become possible. The sky is the limit.
Greater detail about the XFL specification has yet to be released. Certainly it isn’t getting the same amount of air time as sexier features like IK, hardware acceleration, the addition of the z-axis for 3D transforms, or the new advanced text engine, but XFL’s implementation in Flash CS4 could be the kind of killer app that further cements the path for Flash’s longevity.Permalink