class DocumentHandler class DocumentHandler Receive notification of general document events
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| | The virtual document handler interface
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| private | Unimplemented Constructors and operators
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Receive notification of general document events.This is the main interface that most SAX applications implement: if the application needs to be informed of basic parsing events, it implements this interface and registers an instance with the SAX parser using the setDocumentHandler method. The parser uses the instance to report basic document-related events like the start and end of elements and character data.
The order of events in this interface is very important, and mirrors the order of information in the document itself. For example, all of an element's content (character data, processing instructions, and/or subelements) will appear, in order, between the startElement event and the corresponding endElement event.
Application writers who do not want to implement the entire interface while can derive a class from HandlerBase, which implements the default functionality; parser writers can instantiate HandlerBase to obtain a default handler. The application can find the location of any document event using the Locator interface supplied by the Parser through the setDocumentLocator method.
Constructors and Destructor
DocumentHandler()
The virtual document handler interface
virtual void characters( const XMLCh* const chars, const unsigned int length )
The Parser will call this method to report each chunk of character data. SAX parsers may return all contiguous character data in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity, so that the Locator provides useful information.
The application must not attempt to read from the array outside of the specified range.
Note that some parsers will report whitespace using the ignorableWhitespace() method rather than this one (validating parsers must do so).
The SAX parser will invoke this method only once, and it will
be the last method invoked during the parse. The parser shall
not invoke this method until it has either abandoned parsing
(because of an unrecoverable error) or reached the end of
input.
The SAX parser will invoke this method at the end of every
element in the XML document; there will be a corresponding
startElement() event for every endElement() event (even when the
element is empty). If the element name has a namespace prefix, the prefix will
still be attached to the name.
Validating Parsers must use this method to report each chunk
of ignorable whitespace (see the W3C XML 1.0 recommendation,
section 2.10): non-validating parsers may also use this method
if they are capable of parsing and using content models. SAX parsers may return all contiguous whitespace in a single
chunk, or they may split it into several chunks; however, all of
the characters in any single event must come from the same
external entity, so that the Locator provides useful
information. The application must not attempt to read from the array
outside of the specified range.
The Parser will invoke this method once for each processing
instruction found: note that processing instructions may occur
before or after the main document element. A SAX parser should never report an XML declaration (XML 1.0,
section 2.8) or a text declaration (XML 1.0, section 4.3.1)
using this method.
SAX parsers are strongly encouraged (though not absolutely
required) to supply a locator: if it does so, it must supply
the locator to the application by invoking this method before
invoking any of the other methods in the DocumentHandler
interface. The locator allows the application to determine the end
position of any document-related event, even if the parser is
not reporting an error. Typically, the application will
use this information for reporting its own errors (such as
character content that does not match an application's
business rules). The information returned by the locator
is probably not sufficient for use with a search engine. Note that the locator will return correct information only
during the invocation of the events in this interface. The
application should not attempt to use it at any other time.
The SAX parser will invoke this method only once, before any
other methods in this interface or in DTDHandler (except for
setDocumentLocator).
The Parser will invoke this method at the beginning of every
element in the XML document; there will be a corresponding
endElement() event for every startElement() event (even when the
element is empty). All of the element's content will be
reported, in order, before the corresponding endElement()
event. If the element name has a namespace prefix, the prefix will
still be attached. Note that the attribute list provided will
contain only attributes with explicit values (specified or
defaulted): #IMPLIED attributes will be omitted. virtual void endDocument()
virtual void endElement(const XMLCh* const name)
virtual void ignorableWhitespace( const XMLCh* const chars, const unsigned int length )
length - The number of characters to read from the array.
virtual void processingInstruction( const XMLCh* const target, const XMLCh* const data )
data - The processing instruction data, or null if
none was supplied.
virtual void setDocumentLocator(Locator* const locator)
virtual void startDocument()
virtual void startElement( const XMLCh* const name, AttributeList& attrs )
attrs - The attributes attached to the element, if any.
AttributeList
private Unimplemented Constructors and operators
DocumentHandler(const DocumentHandler&)
alphabetic index hierarchy of classes
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