Villanova CSC 9010 - XML Based Course Websites

Unformatted text preview:

XML Based Course Websites Michael Wollowski Computer Science and Software Engineering Department Rose-Hulman Institute of Technology United States of America [email protected] Abstract: XML, the extensible markup language is a quickly evolving technology that presents a viable alternative to courseware products and promises to ease the burden of web authors who edit their course pages directly. XML uses tags to label kinds of contents rather than format information. The use of XML enables faculty to focus on providing contents, leaving the task of rendering contents to experts who provide a single stylesheet used for formatting purposes. This stylesheet has to be edited once, saving time and effort and ensuring consistent appearance of course pages that reference it. However, the major benefit of XML is the ability to provide pinpoint search engines. Additionally, web-based editors can be provided to make editing pages easier. Introduction The Extensible Mark-up Language (XML) is a promising new technology for creating, maintaining, and searching course pages. XML shows the most promise when it comes to searching for information. Furthermore, the use of XML reduces the overhead of editing web-pages by separating form and contents. Content providers have to do just that, provide the contents. Similar web-pages are rendered by a common stylesheet. It only has to be edited once. A common stylesheet ensures uniform appearance of web-pages that are of the same kind. This in turn provides for ease of navigation and recognition of location. When it comes to course web-sites, there are largely two alternatives: to edit and maintain them directly or to use courseware products such as (WebCT 2002) or (Blackboard 2002). The benefits of direct editing are complete control over appearance and contents; the major drawback is a lot of work formatting contents. The benefits of courseware products are ease of use and integration with other academic systems, such as the Banner; a drawback is that formatting and functionality are as provided. We propose a third option which is slowly become a viable alternative: the use of XML. We will show in this paper that XML shares most of the benefits of the two current alternatives: ease of contents creation and maintenance as well as complete control over appearance and contents. A major added benefit of XML is the ability to furnish very precise search engines, enabling users such as students, prospective students, or prospective employers to quickly locate relevant information. Industry started using XML a while ago, chiefly to unify information between companies and their suppliers (Goldfarb & Prescod 2000). We show an application of this technology that demonstrates its benefits for academic use. We will briefly explain the main components of XML and in the process show how XML separates form and contents. We will demonstrate how common information can be placed into separate files, greatly aiding in the maintenance and consistency of course sites. We will show how to is to provide web-based editors as well as search engines for course pages. Finally, we will report on the status of the project. Separation of Form and Contents XML is three technologies in one. It consists of XML proper, which is a language for labeling contents. There are Document Type Definitions (DTDs), which are used to specify kinds of documents. Among others, DTDs specify the labels to be used in XML documents. Finally, there are languages to render XML documents. Typically, web-authors use either the Extensible Stylesheet Language (XSL) or Cascading Stylesheets (CSS). Since XSL is more powerful when it comes to the way final documents canbe composed, we chose XSL over CSS. At this point, only Internet Explorer 5.5 and higher support XSL. Most other browsers support only CSS. In what follows, we present an example of an XML document containing a course description of one of our courses. We want to show how XML supports the separation of form and contents. The challenges of dealing with larger documents such as syllabi will be addressed in the conclusions. Figure 1 shows an XML file containing course description information for CSSE 100, one of our courses. In general, white space does not matter and should be used to enhance readability. XML tags are identified by opening and closing angle brackets. A closing tag is identified by a forward slash preceding its name. An opening and closing tag form an element. To aid in readability, we boldface the tags in this write-up. The second line indicates that this document is of the type as specified in the course_description.dtd document. The third line asks web-browsers to use the course_description.xsl document to render this document. The contents proper is nested inside of the course_description element. There, we find information on the course id, its title, number of credits, and a brief catalog course description. <?xml version=”1.0”?> <!DOCTYPE course_description SYSTEM “course_description.dtd”> <?xml-stylesheet type=”text/xsl” href=”course_description.xsl”?> <course_description> <id> CSSE100 </id> <title> Introduction to Programming and Problem Solving </title> <credits> 2 </credits> <description> An introduction to general methods of problem solving, structured algorithm design, object-oriented techniques, and elementary computer programming. </description> </course_description> Figure 1: XML document for a sample course description Element names are chosen by the author of the DTD. A web-author has the option of using an existing DTD or to design their own. A key principle of XML is that element names are used to indicate kinds of contents. Notice that there is no formatting information present. This is in contrast to HTML, where tags are used to format contents. This is the primary difference between XML and HTML. We will now explore the ramifications of this difference. Since in XML, elements are used to indicate kinds of contents, content providers do not have to be concerned about formatting. This of course greatly simplifies the life of the typical academic web-author, who lacks time to memorize HTML formatting tags and who oftentimes spends considerable effort fiddling with HTML tags to obtain a halfway decent looking web-page. While authors who prefer to edit their documents with plain text editors still have to memorize XML elements, we will show in the section on “Ease of


View Full Document

Villanova CSC 9010 - XML Based Course Websites

Documents in this Course
Lecture 2

Lecture 2

48 pages

Lecture 2

Lecture 2

46 pages

Load more
Download XML Based Course Websites
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view XML Based Course Websites and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view XML Based Course Websites 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?