What's New in QuickTime 5

XML Event-Based Parsing

QuickTime 5 now includes an XML parsing component. In addition to tree-based XML parsing, it supports event-based XML parsing. This is supported through callbacks to the client.

Event-based parsing uses much less memory than the tree-based parser. Basically, it does a callback anytime something interesting happens. To invoke this, you pass the xmlParseFlagEventParseOnly flag to XMLParseDataRef() or XMLParseFile() . The XMLDoc parameter should be set to NULL in this case. The handlers (which need not all be set) are defined as follows:



 
ComponentResult startDocumentHandler(long refcon);

ComponentResult endDocumentHandler(long refcon);

ComponentResult startElementHandler(const char *name, const char **atts, 

                                    long refcon);

ComponentResult endElementHandler(const char *name, long refcon);

ComponentResult charDataHandler(const char *charData, long refcon);

ComponentResult commentHandler(const char *comment, long refcon);

ComponentResult preprocessHandler(const char *name, const char **atts, 

                                    long refcon);

The following APIs set the callbacks along with the common refcon shared among the callbacks:



 
pascal ComponentResult XMLParseSetEventParseRefCon(ComponentInstance 

                                        aParser, long refcon);



 
pascal ComponentResult XMLParseSetStartDocumentHandler(ComponentInstance 

                                        aParser, StartDocumentHandlerUPP 

                                        startDocument);



 
pascal ComponentResult XMLParseSetEndDocumentHandler(ComponentInstance 

                        aParser, EndDocumentHandlerUPP endDocument);



 
pascal ComponentResult XMLParseSetStartElementHandler(ComponentInstance 

                        aParser, StartElementHandlerUPP startElement);



 
pascal ComponentResult XMLParseSetEndElementHandler(ComponentInstance 

                            aParser, EndElementHandlerUPP endElement);



 
pascal ComponentResult XMLParseSetCharDataHandler(ComponentInstance 

                            aParser, CharDataHandlerUPP charData);



 
pascal ComponentResult XMLParseSetPreprocessInstructionHandler(ComponentInstance aParser, 

                                PreprocessInstructionHandlerUPP 

                                preprocessInstruction);



 
pascal ComponentResult XMLParseSetCommentHandler(ComponentInstance 

                                aParser, CommentHandlerUPP comment);

It is the client's responsibility to create and free any UPPs it sets. Also, the atts parameter returned in the start element and preprocess handlers is a character string array that contains the attribute name followed by the attribute value. The list ends with a null terminator.

What's New in QuickTime 5