Supporting device independent and accessible authoring by a next generation Web Publishing Framework

Yehya Mohamad and Carlos A. Velasco
Fraunhofer Institute for Applied Information Technology
BIKA Competence Center
Schloss Birlinghoven, D53757 Sankt Augustin (Germany),
W3C Workshop on Device Independent Authoring Techniques, St. Leon-Rot, Germany


Users access information systems with a variety of devices, and with different interaction modes that depend on personal characteristics (including disabilities) and on the context of usage. Content and information providers must deal with this demand and search for the ideal of authoring once, delivering for multiple profiles. The authors will present in the paper a conceptual development in which an Open Source Web Publishing Framework (Apache Cocoon) that supports Separation of Concerns, can be used to simplify device independent web authoring in conjunction with user/device profiles implemented as Web Services.

Authoring for device independence and, multimodality and accessibility

Web authoring is no longer reduced to the maintainance of a set of HTML pages to keep some Internet presence for any given institution. The growth in the number of devices able to access the Internet, together with the growing complexity of Internet applications (e-commerce, portals, web syndication, etc.), demands from information providers a great effort to maintain different versions of their Internet offer.

The old paradigm "program once, run anywhere" can be now be translated to "author once, present anywhere". There are different types of roles (Mazzocchi, 2000; Lewis, 2002, presents a similar approach) when creating web content:

Figure displaying the four authoring roles, and their relationships: management-logic, management-content, management-style, logic-content and content-style
Figure 1. Separation of Concerns in Cocoon (after Mazzocchi, 2000).

Actual Content Management Systems (CMS) partially support information providers in their tasks. However, they still present several limitations (we will not consider the issue of growth saturation in web development, see for instance Mazzocchi, 2001, for a discussion on the topic):

Bearing in mind the previously listed limitations, these are the requirements for device independent and accessible authoring:

Implementation in a web publishing framework

The proposed implementation is achieved through an Open Source Web Publishing Framework from the Apache Foundation called Cocoon. Cocoon is a powerful Java Servlet framework that allows the server-side transformation of XML documents via pipelined SAX events. Cocoon can also interact with also any data source: filesystems, RDBMS, native XML databases, LDAP, WebDAV, etc. The list of technologies supported by Cocoon include, among others: XSL-FO, XSLT, SVG, CC/PP, XForms, and of course, Web Services.

The integration follows this scheme:

The implementation of user/device profiles has been discussed by the authors elsewhere (Velasco and Mohamad, 2002). It shall be stressed that whereas for device profiling, an acknowledged recommendation (CC/PP) exists, that is not the case for user profiling, with the exception of the Platform for Privacy Preferences, P3P. This is particularly important when considering users with disabilities, where the application of device profiling techniques fails short. The authors are investigating a profiling «cascading model» for content delivery similar to CSS where user profiles have higher priority than device profiles characteristics.

We want to highlight that ATAG-compliance not only implies that the produced content is accessible, but also that the authoring environment must be accessible to authors with disabilities. With Cocoon and XForms it is feasible to implement this essential requirement.


The discussed approach presents a set of benefits for content providers:


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