xmlsax

XMLSAX is a term used to describe the use of the SAX (Simple API for XML) interface for parsing XML data. It emphasizes streaming, event-driven parsing rather than building a complete in-memory representation.

Core concepts: A SAX parser reads XML from a stream and triggers callbacks or handler methods for events such as startDocument, endDocument, startElement, endElement, characters, and processingInstruction. Applications implement a content handler to respond to these events.

Typical usage: In languages with SAX support, the developer registers a content handler with the parser, feeds an input source (file, stream, or string), and processes events to extract data or perform transformations on the fly. This approach is memory-efficient and suitable for large inputs.

Comparison: Compared with DOM-based parsing, SAX does not keep the full document tree in memory, enabling lower memory usage but requiring more careful state management. StAX is another streaming option with pull parsing.

History and scope: SAX originated in the 1990s as part of early XML toolchains. XMLSAX labels are used in various language ecosystems to refer to SAX-based parsing facilities; some projects implement their own ContentHandler interfaces named similarly.

Limitations and considerations: Error handling in SAX is event-driven; well-formedness errors may terminate parsing; namespaces support varies; streaming models require careful handling of character data that may be split across events.