Gord Bowman writes "For anyone familiar with XML and, specifically, with SVG (Scalable Vector Graphics), you may be aware that SVG is increasingly being used for the creation of data-driven Web applications. But everyone has been doing so by handcoding script and/or XSLT, without the benefit of an IDE to help. Seeing such a need for a tool, my company (Corel) set about creating one." and 'lo, dSVG was born. Gord Bowman is the lead developer of dSVG and would like you to take a look at the dSVG specs (you can find the link, in the full article) and offer your comments.
"It quickly became apparent that while getting a grasp of XSLT is difficult and time-consuming, even more time-consuming was all the scripting it took to create the level of interactivity required on the client via script. Thus we set about creating a library of generic script functions that would assist developers in creating their Web apps. But it didn't take long to realize that this was no good--you can't data-map and transform (via XSLT) functions like you can markup. And, unlike markup, it's much more difficult to auto-generate and customize script via an authoring tool. So I set about designing an XML markup language, implemented with script (so as to work in any SVG viewer), which would describe UI controls and behaviours, so as to facilitate the creation of SVG-based Web applications.
It was a programmer's dream. I was essentially being paid to develop a new kind of programming language. One that, like XSLT, is XML-based but is more procedural in nature and thus easier for the average developer to grasp. It's also easier for non-developers to grasp it, thus bringing SVG and application development to a whole new class of user. A year later, dSVG (Dynamic SVG) was unveiled to the public as part of the Corel Smart Graphics Studio. And as of yesterday, the full dSVG 1.1 Specification and Test Suite became available for download.
The UI controls were designed to allow complete customization of appearance, and to allow for use with forms without being tied to a forms-specific model. The behaviors were designed to be generic and higher level than DOM methods, so as to be more intuitive to non-developers. The resulting markup language allows data-driven Web applications to be created with little or no need for scripting.
While script is very useful and powerful, markup has many advantages:
- markup is more easily understood by non-developers
- markup can be easily data-mapped and transformed using XSLT
- markup can be easily generated via an authoring tool and customized by the author
- markup is semantically meaningful, promoting interoperability on the authoring side
- markup can be standardized, thus helping the adoption of SVG
dSVG was implemented with script so as to work in different SVG Viewers. However, Corel has proposed dSVG to the SVG Working Group in the hopes that through a collaborative effort, dSVG will lead to the eventual creation of standard markup for UI controls and behaviors. These could then be natively implemented, bringing about even more advantages:
- less data to transfer
- less need for a script engine on small devices (which can take up a significant part of the footprint)
The dSVG 1.1 spec and test suite was posted for download with the goal of allowing the developers and non-developers to experiment with the markup and to provide feedback. This feedback will help me to improve upon dSVG and will also help the SVG Working Group to better assess how the developer community feels about such standard markup being added to the spec for the purpose of developing SVG-based Web applications.
I hope you will take the time to read through the dSVG spec, try out the test suite, and perhaps even create some of your own content. As the creator, I am obviously passionate and excited about dSVG. And having seen how quickly even non-developers can create Web apps, I feel certain that XML-based programming makes sense and is the way of the future. But being a long-time reader of Slashdot, I would love to hear what the Slashdot community thinks. dSVG may not lead to world peace, but I think it has the potential to change the fundamental way in which Web applications are created.
I look forward to hearing your comments.
Lead Developer, Corel Corporation"