Release 10.1A: OpenEdge Development:
Programming Interfaces

Understanding Progress SAX

If you have already handled XML documents using the Progress 4GL support for DOM, then you know that an XML document in the 4GL environment can be represented by an X-document object. An XML element can be represented by a X-noderef object and their attributes and methods, all of which are documented in OpenEdge Development: Progress 4GL Reference .

Progress SAX interface provides three 4GL objects with attributes and methods:

SAX-reader
SAX-attributes
SAX-writer

The Progress SAX-reader lets you do the following:

Provide callback procedures for the SAX API to automatically invoke as it parses a document.
Toggle DTD and XML Schema validation and namespace processing.
Parse an XML document with one call or multiple calls.
Monitor the state of a parse.
Detect and handle errors.

The Progress SAX-attributes object is automatically created and destroyed to handle attributes that need to be added to a document element during the parse.

These topics are discussed in the following sections:

SAX-reader object
Progress SAX callbacks
SAX-attributes object
Validation
Namespace Processing
Parsing with one call or with multiple calls
Monitoring the state of the parse
Error handling