Purposes of this assignment:

• To get you started using XML, DTDs, and CSS.

Idea of the assignment:

In the previous assignment, you wrote a “Browser Helper” that created an HTML page or added information to an existing HTML page that your program had created earlier. This information consisted of:

• A title for the entire page
• A number of items, each consisting of
  • A title for an HTML page
  • The URL of the web page (clickable, not necessarily displayed)
  • Comments about the web page (entered by the user)

For example,

In this assignment, you are to write a revised version of your Browser Helper that produces XML output, rather than HTML output. Your XML should contain all the content information, as above. In addition to the XML, you need:

• A DTD that describes your XML, and
• CSS that tells how to display your XML in a browser.

Sadly, this program is less useful than the first assignment. This should be no surprise. The Browser is designed for use by humans, and HTML is designed for humans, but XML is designed for computers. It may be that, later in the course, we will write programs to process the output of your XML Browser Helper.

Details:

How good is your programming style? If you can easily replace the HTML generation with XML generation, either by replacing a single class or by replacing one or two methods, then you did the first assignment properly. If you have to totally revise your program by ripping out System.out.println statements and putting in new ones, then you haven't properly separated the program logic into replaceable components.

You should probably use an embedded DTD. An embedded DTD means that you have to have a method or methods to output the DTD code; it's not a lot of extra work, but is a lot of clutter with System.out.println statements. If you use an external DTD, it may not work with your browser. If you can use an external DTD and figure out how to make it work with both Internet Explorer and Netscape/Mozilla, that's worth extra credit (I don't know if this is possible.)

I would recommend using an external CSS if possible, but you can use an internal one if that doesn't work. The advantages of an external CSS are (1) you only have to write it once, (2) you don't need a bunch of System.out.println statements to put it in your XML file, and (3) all your XML documents will have the same style. The disadvantage of an external style sheet is that all your XML files will need to be able to find it; this means either (1) all your XML files must be put in the same directory, or (2) you have to use an absolute path name--that is not allowed for this assignment (and a terrible idea in general), because that would make it very difficult for us to use and to grade.

Remember that the Browser Helper in the first assignment could work with multiple files (although only one at a time). Your revised Browser Helper must be able to do the same.

For the XML, invent your own tags. Do not use the HTML tags; use different names. The names should reflect the structure (content) of the document, and should not say how it should be displayed. There is one exception: You can use the <a> tag with the href attribute for your links.

Finally, don't expect to get output that looks as beautiful as you can produce with HTML.

Due date:

Wednesday, September 24, before midnight. Turn in a zipped set of files via Blackboard.