Learn XML

Learning the basics about XML is important in the successful use of XML on z/TPF. Because XML is an evolving technology, any XML education that could be provided here would most likely be out of date within a few months. In addition, there are many resources available for learning the detailed syntax of XML documents, DTDs, and the XML Schema language. To find these resources, do a search on any Internet search engine or browse the technology section of your local book store. You will find lots of information, Web sites, and tools that will assist you in writing XML documents. We have included a few titles and Web pages in Resources that we found useful while porting the XML4C parser to z/TPF. The list is by no means exhaustive, but provides you with a few places to start.

The following list identifies the core pieces of XML that you should understand before writing applications that use XML4C parser 3.5.1 on z/TPF:

  • XML is Unicode 3.0 compliant.
  • A schema is used to define the tags and structure of an XML document. Two types of schema are XML Schema and DTD.
    Note: XML Schema support in XML4C parser 3.5.1 is limited to a subset of the W3C XML Schema language and is considered experimental at this time. For more information about XML Schema support in this parser, go to XML4C version 3.5.1 information.
  • An XML namespace is simply a two-part naming system used for qualifying element and attribute names used in an XML document.
  • XML documents must be well-formed and may be valid based on an associated DTD. Depending on the encoding used, you may be able to open your XML document in Microsoft Internet Explorer Version 5.0 or later to see if it is well-formed.
  • XML documents contain elements and attributes.
  • The parser specifications supported on z/TPF are DOM (versions 1.0 and 2.0) and SAX (versions 1.0 and 2.0). (The experimental IDOM API is also available, but is not supported for production work.)
  • On z/TPF, the schema (DTD or XML Schema) must reside either in the XML document or in the z/TPF file system. An XML document can reside in the file system, reside in memory, or be passed through standard input (stdin). See the following z/TPF information for more details about the z/TPF collection support file system:
    • z/TPF Application Programming
    • z/TPF C/C++ Language Support User's Guide
    • z/TPF Concepts and Structures
    • z/TPF Operations.