Nowadays, a large quantity of data is available through Web pages. This offers a lot of well known advantages but in numerous cases the use of a DBMS to manage this data is also necessary. In this case web pages are generated to display data issued by queries to databases. Most DBMSs [1][3] provide tools to export data to the Web by "generating" HTML pages with predefined structures. However, the existing data exportation tools are proprietary solutions that often provide little flexibility for customization of the pages and when the possibility exists it is still a laborious task as the user has to modify/provide the HTML code.
The main objective of our project is to propose a tool that allows to specify the formatting of the query result in a simple and declarative way. We intend to avoid that the user has to learn the stylesheets languages [4][6] and to facilitate the customization of the displaying of data. With our tool, data formatting is expressed by masks defined using a simple Mask Definition Language (DML). Different masks may be defined for the same query allowing to publish the data in different ways.
Our tool is not targeted to a particular DBMS in order to support queries to different databases. We consider queries expressed in OQL [2] that may retrieve complex objects including images and audio.
Having a query-mask pair our tool will generate the corresponding files to construct the web pages. The query's answers will be expressed under XML [5] and its DTD and the mask will be translated into an XSL[6] stylesheet. This approach allows us to keep the separation of content and presentation and to take advantage of the expressive power of XML and XSL.
[2] ODMG, The Objects Database Standard:ODMG 2.0, vol. , Morgan Kaufmann Pub.., California, USA, 1997.
[3] Versant, VersantWeb architecture , , http://www.versant.com/, 1998.
[4] W3 Consortium, Cascading Style Sheets, level 2, CSS2 Specification, , W3C Recommendation REC-CSS2-19980512, http://www.w3.org/TR/REC-CSS2, May 1998.
[5] W3 Consortium, Extensible Markup Language (XML) 1.0', W3C Recommendation REC-xml-19980210, http://www.w3.org/TR/1998/REC-xml-19980210, Feb. 1998.
[6] W3 Consortium, Extensible Stylesheet Language (XSL) Specification, W3C Working Draft, http://www.w3.org/TR/WD-xsl, Apr. 1999.