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XML Resume Test Drive

Also relates to Java and XML Schema

The Sourceforge project XML Resume is an excellent tool for compiling a resume quickly in different formats (although I find the current document type definition slightly limited). It is well packaged and quick, and easy, to configure and run the examples with the Make utility, also offering some convenient filtering features. Unfortunately however, my personal resume was reluctant to build, with Xalan returning an ArrayIndexOutOfBounds exception.

Once I broke the XML instance apart, the error was soon tracked down. Using XML Spy to create the instance, I had inadvertantly left empty values in a couple of the level attributes for skill content. Since the attribute-list declaration in the DTD is

<!ATTLIST skill level CDATA #IMPLIED>

the instance still validated, so I missed the error.

One resolution is to wrap the contents of the XSLT template for skill/@level within another conditional statement that tests the length of the attribute value.

<xsl:template match="skill/@level">
  <strong><xsl:if test="string-length() > 0"></strong>
    […]
  <strong></xsl:if></strong>
</xsl:template>

However, this burden shouldn't fall to the transformation file, since it is the role of the Schema/DTD to define the contract for the instance. DTD syntax has no means to prevent this error, while in XML Schema it is simply a matter of defining a custom simple type.

<xsd:simpleType name="nonZeroString">
	<xsd:restriction base="xsd:string">
		<xsd:pattern value="\w.*"/>
	</xsd:restriction>
</xsd:simpleType>

In this example the pattern facet requires the attribute value to be at least one word character. The facet <xsd:minLength value="1"/> serves the same purpose sans regular expressions. An XML Schema shell has recently been posted in the project's forum.

Posted on Mar 01, 2004 at 05:15:57. [Comments for XML Resume Test Drive- 0]

XML Parsing Snippets

Also relates to Java

Recently been testing the main XML parsing methods in Java a bit, giving me the chance to play around in Eclipse and broaden my Java and XML knowledge. Previously I have only really used the DOM parser in the Apache Xerces package, since this equates well to similar Javascript DOM coding for HTML documents.

While the DOM is an excellent choice for document manipulation, the event driven nature of SAX makes it an excellent choice for extracting particular information from a document.

This very simple code snippet shows the contents of a Class extending org.xml.sax.helpers.DefaultHandler to display the level of nesting in an XML (or HTML) document, by utilising the Stack data structure.

private java.util.Stack stack = new java.util.Stack();

[.. snip ..]

public void startElement(
	String namespaceURI,
	String localName,
	String qName,
	Attributes atts)
	throws SAXException {
	if (stack.size() > 0)
	{
		short temp = (short)stack.size();
		while (temp– > 0)
		{
			System.out.print("t");
		}
	}
	System.out.println(localName);
	stack.add(localName);	
}
public void endElement(
  String namespaceURI,
  String localName,
  String qName)
	throws SAXException {
		stack.pop();		
}	

JDOM also offers some interesting classes for XML parsing with a more Java-centric approach. In particular the contributed ResultSetBuilder Class in the org.jdom.contrib.input package offers a very concise API for converting SQL data into an XML document.:

s = conn.createStatement();
rs = s.executeQuery(query);

ResultSetBuilder builder = 
	new ResultSetBuilder(rs,
		"library", "book", 
		Namespace.getNamespace(namespace));
builder.setAsAttribute("isbn");
builder.setAsAttribute("format");
Document doc = builder.build();

XMLOutputter outp =
  new XMLOutputter("  ", true);
outp.setTrimAllWhite(true);
outp.output(doc, 
	new FileOutputStream(fileID));	

Posted on Nov 08, 2003 at 03:19:49. [Comments for XML Parsing Snippets- 0]