Keywords
Citation
Keary, M. (2001), "The ABCs of XML: The Librarian’s Guide to the eXtensible Markup Language", The Electronic Library, Vol. 19 No. 1, pp. 49-53. https://doi.org/10.1108/el.2001.19.1.49.4
Publisher
:Emerald Group Publishing Limited
With electronic commerce (e‐commerce) fast becoming a reality, indexers and information professionals need to update their skills. They will have to acquaint themselves with languages used on the World Wide Web, so that they can contribute to managing the unstructured data that exists on the Internet, and within organisations they serve. This guide is written for that purpose, as it presents an overview of XML – a meta language or computer language for describing languages. XML provides the syntax that allows users to create their own markup language, and define their own vocabularies to meet specific application or industry needs. They can also structure data in an XML document to suit their needs and to describe as necessary. Thus, XML can be used to describe data components, records and other data structures.
XML actually stands for “the eXtensible Markup Language”, and is related to SGML, Standard Generalized Markup Language. The author briefly shows the relationship between them, and also considers the document type definition (DTD) that both languages use. Unfortunately, the text is littered with computer jargon, but the aim is to explore some library applications that use XML. The principle underlying XML is that the content of documents should be accessible to and readable by both humans and machines (computer software). Thus, the XML format contains a mixture of text and markup (tags), which organize and identify the components of a document that consists of elements and entities.
An XML document has to be read and displayed for others to read. For that we need document style semantics and specification language (DSSSL) used by SGML and Cascading Style Sheets used in HTML, to examine the features of the eXtensible Style Language (XSL). An example of style sheets in use is provided, plus its ability to accommodate multimedia elements for dissemination via the Internet. The final stage of XML includes capabilities for linking (absolute keywords, relative keywords and string matching), as well as the use of interactive pointers that permit retrieval of resources contained within XML documents.
In chapter 5, Desmarais describes how a parser (processing software) uses XML markup to process and manipulate the information content, based on two approaches – event‐driven or simple Application Programming Interface (API) for XML (SAX); or tree‐manipulation method using the Document Object Model (DOM). He then raises issues related to managing XML documents, and finally explores in detail how XML can establish electronic commerce by bringing EDI to the desktop. Development tools for getting started, a glossary and bibliography complete this text.
The book is not an easy read, but what it does is to bring you up to date on the language approved by the World Wide Web Committee (W3C), although things may have already moved on as that was in early 1998. However, the author intends to update the contents of this book and the address of the Web site is provided; please refer to – http://www.newtechnologypress. com/updates/xml.html.