14. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform: receiving streaming input that represents XML data at a stream-based parser; said stream-based parser receiving at runtime, a set of XPaths and associated content handler instance for registration; wherein each XPath of the set of registered XPaths is associated with a separate content handler of a plurality of content handlers that are registered with said stream-based parser; evaluating events from the stream-based parser against the registered XPaths; and detecting whether received streaming input includes an XPath that matches a registered Xpath; in response to detecting that received streaming input includes an XPath that matches a registered XPath, reading registration information to identify a particular content handler instance that has been registered for said registered XPath, and calling said particular content handler instance.
14. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform: receiving streaming input that represents XML data at a stream-based parser; said stream-based parser receiving at runtime, a set of XPaths and associated content handler instance for registration; wherein each XPath of the set of registered XPaths is associated with a separate content handler of a plurality of content handlers that are registered with said stream-based parser; evaluating events from the stream-based parser against the registered XPaths; and detecting whether received streaming input includes an XPath that matches a registered Xpath; in response to detecting that received streaming input includes an XPath that matches a registered XPath, reading registration information to identify a particular content handler instance that has been registered for said registered XPath, and calling said particular content handler instance. 16. The computer-readable storage medium of claim 14 , wherein the particular content handler instance implements an interface for reporting start of XPath events and end of XPath events.