Sjoerd Visscher's weblog
My ideas about new web technology that can change the future of the world wide web.
< Monday, October 28, 2002 >
Connecting people to XML
Structured editing of schema-controlled XML data is a hard challenge to meet. Tools that would make the task easy and natural are nowhere in sight. [John Udell]
Maybe John Udell still hasn't seen Xopus. I can't blame him. We (Q42) don't have a marketing department, and our Xopus site looks like we don't want you to use it. But Xopus does seem to be what John Udell is looking for.
All actions in Xopus are schema controlled. If the schema doesn't allow it, the user can't do it. This doesn't stop with structural actions, like 'can you add one or more Authors to a Book', but markup is also restricted by the schema. Can a user only add bold and italic, or also lists and tables? And if the user can add links, is he then allowed to add a target attribute? This is a big issue for CMSs, where the site designers want to give the site a consistent look and feel, but where the editors keep messing things up.
Another issue is usability and discoverability. Users know how to work with Word. And so Xopus provides the standard Word-like interface, like toolbars, context-menus, and some (not too many) dialogs. But a user must do more than edit some XHTML. For example, the University of Groningen allows teachers to edit course descriptions and other course related data using Xopus. The two options they had before were either teach the teachers to use an XML editor, or build huge amounts of html forms more or less by hand.
But Xopus allows the university to take a much easier approach. The webpages of each course were already built from the XML data with XSL transformations. Xopus uses these XSL files to show the XML data in exactly the same way, only this time the content is editable. So the teachers now have a familiar user interface to edit their data in a familiar layout. And that's not all.
The teacher doesn't even have to know the storage structure of the CMS. If he wants to edit his course, he fires up his browser and he surfs to the webpage of the course. And because the system can recognize the teacher, an extra link appears to edit the course. When clicked, the Xopus toolbar slides in and the course data becomes editable. (Not the whole page is editable, just the parts specific to the course.)
At Q42 we're very proud of this product, and we made it open source and freely downloadable. It works in IE5.5 and up, and we know we can make it work in Mozilla. Only we're missing the financial support to do this. Everybody who knows Xopus thinks this is a shame, and we really want to do it, but the reality of running a business doesn't let us. Just one link to end this story: the online demo.