poco/XML/include/Poco/SAX/LexicalHandler.h

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2012-04-29 20:52:25 +02:00
//
// LexicalHandler.h
//
// $Id: //poco/1.4/XML/include/Poco/SAX/LexicalHandler.h#1 $
//
// Library: XML
// Package: SAX
// Module: SAX
//
// SAX2-ext LexicalHandler Interface.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
2012-04-29 20:52:25 +02:00
//
#ifndef SAX_LexicalHandler_INCLUDED
#define SAX_LexicalHandler_INCLUDED
#include "Poco/XML/XML.h"
#include "Poco/XML/XMLString.h"
namespace Poco {
namespace XML {
class XML_API LexicalHandler
/// This is an optional extension handler for SAX2 to provide lexical information
/// about an XML document, such as comments and CDATA section boundaries.
/// XML readers are not required to recognize this handler, and it is not part of
/// core-only SAX2 distributions.
///
/// The events in the lexical handler apply to the entire document, not just to the
/// document element, and all lexical handler events must appear between the content
/// handler's startDocument and endDocument events.
///
/// To set the LexicalHandler for an XML reader, use the setProperty method with the
/// property name http://xml.org/sax/properties/lexical-handler and an object implementing
/// this interface (or null) as the value. If the reader does not report lexical events,
/// it will throw a SAXNotRecognizedException when you attempt to register the handler.
{
public:
virtual void startDTD(const XMLString& name, const XMLString& publicId, const XMLString& systemId) = 0;
/// Report the start of DTD declarations, if any.
///
/// This method is intended to report the beginning of the DOCTYPE declaration;
/// if the document has no DOCTYPE declaration, this method will not be invoked.
///
/// All declarations reported through DTDHandler or DeclHandler events must appear
/// between the startDTD and endDTD events. Declarations are assumed to belong to
/// the internal DTD subset unless they appear between startEntity and endEntity
/// events. Comments and processing instructions from the DTD should also be reported
/// between the startDTD and endDTD events, in their original order of (logical) occurrence;
/// they are not required to appear in their correct locations relative to DTDHandler or
/// DeclHandler events, however.
///
/// Note that the start/endDTD events will appear within the start/endDocument events from
/// ContentHandler and before the first startElement event.
virtual void endDTD() = 0;
/// Report the end of DTD declarations.
///
/// This method is intended to report the end of the DOCTYPE declaration; if the document
/// has no DOCTYPE declaration, this method will not be invoked.
virtual void startEntity(const XMLString& name) = 0;
/// Report the beginning of some internal and external XML entities.
///
/// The reporting of parameter entities (including the external DTD subset) is optional,
/// and SAX2 drivers that report LexicalHandler events may not implement it; you can use the
/// http://xml.org/sax/features/lexical-handler/parameter-entities feature to query or control
/// the reporting of parameter entities.
///
/// General entities are reported with their regular names, parameter entities have '%'
/// prepended to their names, and the external DTD subset has the pseudo-entity name "[dtd]".
///
/// When a SAX2 driver is providing these events, all other events must be properly nested
/// within start/end entity events. There is no additional requirement that events from
/// DeclHandler or DTDHandler be properly ordered.
///
/// Note that skipped entities will be reported through the skippedEntity event, which is part of
/// the ContentHandler interface.
///
/// Because of the streaming event model that SAX uses, some entity boundaries cannot be reported under
/// any circumstances:
///
/// * general entities within attribute values
/// * parameter entities within declarations
///
/// These will be silently expanded, with no indication of where the original entity boundaries were.
///
/// Note also that the boundaries of character references (which are not really entities anyway) are not reported.
///
/// All start/endEntity events must be properly nested.
virtual void endEntity(const XMLString& name) = 0;
/// Report the end of an entity.
virtual void startCDATA() = 0;
/// Report the start of a CDATA section.
///
/// The contents of the CDATA section will be reported through the regular characters event;
/// this event is intended only to report the boundary.
virtual void endCDATA() = 0;
/// Report the end of a CDATA section.
virtual void comment(const XMLChar ch[], int start, int length) = 0;
/// Report an XML comment anywhere in the document.
///
/// This callback will be used for comments inside or outside the document element,
/// including comments in the external DTD subset (if read). Comments in the DTD must
/// be properly nested inside start/endDTD and start/endEntity events (if used).
protected:
virtual ~LexicalHandler();
};
} } // namespace Poco::XML
#endif // SAX_LexicalHandler_INCLUDED