Web Ecology: Recycling HTML Pages as XML Documents Using W4F

This paper presents the World-Wide Web Wrapper Factory (W4F), a Java toolkit to generate wrappers for Web data sources. Some key features of W4F are an expressive language to extract information from HTML pages in a structured way, a mapping to export it as XML documents and some visual tools to assist the user during wrapper creation. Moreover, the entire description of wrappers is fully declarative. As an illustration, this paper demonstrate how to use W4F to create XML gateways, that serve transparently and on-the-y HTML pages as XML documents with their DTDs.