Ad Emmen
Genias Benelux
James Stewartstraat 24
NL-1325 JN Almere
The Netherlands

emmen@genias.nl
http://www.genias.nl//

This is not an introduction into XML, but gives some directions how to start running XML-applications and the exercises used in an XML training course.

November 2001
Almere

• A text-editor
  • Any text editor is OK
  • Should have line and column numbering
  • Save texts as text-only (plain ASCII or UTF-8)
  • Standard .xml is used as file extension
• An XML-parser
  • For instance use MS-Explorer version 5.0 or higher, Netscape 6, or Opera
  • Use stand-alone parser like Xerces, or XP
  • If you want to validate documents you need a validating parser like Xerces
  • Start with a non-validating
• Write your XML-document in the editor, the parse it
• There are also special XML-editors, but that is for later

• Create an XML-document
• Also include attributes and children
• See what is happening when you:
  • Do no start with the <?xml instruction
  • Have more that one document-element
  • Do not close tags and attributes
  • Use the same attribute twice
  • Include special characters

The most important rules are:
• All tags are opened and closed
• Close empty tags with />
• There is one unique root element
• Elements may not overlap
• Attribute values are between quotes
• The characters < and & are only used to start elements and entities
• Use only the five predifined entities
• Tag names are case sensitive

• Create an xml-document
• Open it from within MS-Explorer 5.0 or higher
• Errormessage: An error occured passing the XML file
• Info on line and column number of the error
• Or open it in Netscape 6.0
• XML parser error: not well-formed

An XML-document is valid when it:
• Is well-formed
• Has a DTD (Document Type Definition)
• Complies with the constraints in the DTD

An XML-document is schema-valid when it:
• Is well-formed
• Has a Schema
• Complies with the constraints in the Schema

• For instance Xerces in command-line mode on a Unix system:
• #java dom.DOMCount -v database/xml-slides.xml
• Result:

        [Error] xml-slides.xml:2:59: Element type "slides" must be declared.
        [Error] xml-slides.xml:2:59: Attribute "name" must be declared for element type "slides".
        [Error] xml-slides.xml:2:59: Attribute "size" must be declared for element type "slides".
        database/xml-slides.xml: 3577 ms (552 elems, 6 attrs, 0 spaces, 18611 chars)
        

• On Windows use java, jview or jre and reverse the slash
• On Macintosh: use Jbindery from MRJ SDK tools

<?xml version="1.0" ?>
<?xml-stylesheet type="text/css" href="../css/plain.css"?>
<!DOCTYPE slides SYSTEM "slides.dtd>

<slides name="XML-getting-started" size="5" colour="#000000">
<title>XML getting started </title>

<!--  This is a comment -->

<slide>
<title>XML - Getting started</title>
<content>
  <p align="center">
  Ad Emmen<br/>
  Genias Benelux<br/> 
   </p>
  <p align="center">January  2001<br />
  Almere<br />
 </p>
</content>
</slide>

</slides>

 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 

• Must be included and must be the first line in an XML-document
• Version number must be included and always be "1"
• Encoding attribute is optional. Defines character-set
• Standalone attribute is optional. Defines whether the document needs a DTD to be checked

 <?xml-stylesheet type="text/css" href="../css/plain.css"?>
 <?xml-stylesheet type="text/xsl" href="../xsl/plain.xsl"?>
 
 

• Optional processing instruction
• Used in combination with a web browser
• CSS2 with Netscape 6 or Opera
• XSL with Explorer 5
• In standard Explorer 5 an old version of XSLT is supported. Dowload a new DLL (not the complete browser!)

  <!DOCTYPE slides SYSTEM "slides.dtd">

• Defines the DTD for the XML document
• Optional
• The name "slides" in this case much match the root element name
• After the SYSTEM parameter the location of the DTD can be given
• You can also include definitions locally in the DOCTYPE definition

  <slides> ... </slides>
 

• An element is the basic unit of XML-documents
• All elements have a start-tag and a closing tag
• Everything between the tags is called the element-content
• An element can contain other elements, comments, and text
• The start tag can have attributes
• There must be one and only one element that encloses all others: the root element

  <br> </br>
  <br />

• Elements with no content are called empty elements
• The closing tag can than be abbreviated to slash in the opening tag
• An empty element can have attributes though

  <slides name="XML-getting-started" size="5" colour="#000000">

• Attributes have a identifying name and a value
• Unlike in HTML, attributes must have a value
• Value must be within single or double quotes
• Attributes on the same element must have a different name

 ]]>
 

• Comments can be used to clarify the content of XML-documents
• Only intended for human readers
• Comments cannot be embedded in other comments

  >
 

• Use &gt; when > is needed
• There are only five predifined entities in XML
  • &: &amp;
  • <: &lt;
  • >: &gt;
  • ": &quot;
  • ': &apos;

• Create a well-formed XML-document
• Use CSS to display it in a browser

• Create a well-formed XML-document representing your music collection
• Include CD's, MP3, or whatever else you have
• Include information on each track, artist, etc
• Include information on running-time, location of a picture of the box, etc.
• Define your own elements and attributes
• Do not use any element you know from HTML!

• First step instructions in CSS-presentation
• Create a wellformed XML-document include the xml-stylesheet processing instruction
• Create a CSS stylesheet
• Open the XML-document in a XML browser with CSS support

• Download an XSLT processor, for instance XT
• On Windows (command-mode): xt xml-file xsl-file result-file
• On Unix: first set the classpath to include xt.jar, xp.jar and sax.jar
• Then: java -cp xt.jar:xp.jar:sax.jar com.jclark.xsl.sax.Driver xml-file xsl-file result-file
• on MacOs-9: Use Jbindery
• You can pass additional parameters to xsl:variable elements at the top-level in the stylesheet
• xt xml-file xsl-file result-file parameter1=value1 parameter2=value2

• The XSLT processor first calls a parser to check the xml and xslt files
• Then it performs the transformation on the xml-file using the stylesheet in the xsl-file and producing the result-file
• Mind using the right name-space parameter on the stylesheet, otherwise nothing seems to happen

• Write a transformation stylesheet that creates an HTML file displaying your music-collection
• Give it a nice lay-out
• Calculate total collection duration
• Make selections on artist, song title, etc.
• Create some working links to sites

• Write a transformation stylesheet that transforms your description of a music-collection into the 'standard one'
• Convert your time duration to MPEG7-style
• Check that your description can use the 'standard' stylesheet to be displayed

• Improve your music collection description
• Put a version of the XML-file on your web site that is general accessible

• With iiepster you access information about the music collections of anyone who has registered
• Structure:
  • Put a file with your music collection in standard description on your web site (everyone)
  • Register it in a iiepster.xml file
  • Run xt iiepster.xml iiepster.xsl iiepster.html and get a listing of all music collection
  • Run xt iiepster.xml search-iiepster.xsl iiepster-search.html familyname="rose" title="De" and watch the search-results
  • All the necessary files are in the iiepster and music directories
  • You can also search on songtext
• Modify the iiepster.xsl stylesheet so that it counts all tracks and calculates the complete duration of the complete iiepster collection
• Modify the search-iiepster.xsl stylesheet so that you can also search on the Genre of the Album

• A number of files/examples are in the directory jelle
• Check whether you can read the jelle.smil file. If not search for another player
• jelle.xml is an excerpt from an standard music file
• jelle.xsl converst this to jelle.smil use:
• xt jelle.xml jelle.xsl jelle.smil
• MP3 and JPG files are added in jelle.xsl
• Now try:
  • Check whether the .smil file works
  • Download a SMIL tutorial
  • Produce an own songtext file
  • Collect images and sound
  • Modify the .xsl file to include your multimedia material
  • Run the stylesheet (with xt) and view the smil output