mirror of
https://github.com/pocoproject/poco.git
synced 2025-10-30 05:29:41 +01:00
87 lines
3.3 KiB
C++
87 lines
3.3 KiB
C++
//
|
|
// EntityResolver.h
|
|
//
|
|
// Library: XML
|
|
// Package: SAX
|
|
// Module: SAX
|
|
//
|
|
// SAX EntityResolver Interface.
|
|
//
|
|
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
|
|
// and Contributors.
|
|
//
|
|
// SPDX-License-Identifier: BSL-1.0
|
|
//
|
|
|
|
|
|
#ifndef SAX_EntityResolver_INCLUDED
|
|
#define SAX_EntityResolver_INCLUDED
|
|
|
|
|
|
#include "Poco/XML/XML.h"
|
|
#include "Poco/XML/XMLString.h"
|
|
|
|
|
|
namespace Poco {
|
|
namespace XML {
|
|
|
|
|
|
class InputSource;
|
|
|
|
|
|
class XML_API EntityResolver
|
|
/// If a SAX application needs to implement customized handling for external entities,
|
|
/// it must implement this interface and register an instance with the SAX driver using
|
|
/// the setEntityResolver method.
|
|
///
|
|
/// The XML reader will then allow the application to intercept any external entities
|
|
/// (including the external DTD subset and external parameter entities, if any) before
|
|
/// including them.
|
|
///
|
|
/// Many SAX applications will not need to implement this interface, but it will be
|
|
/// especially useful for applications that build XML documents from databases or other
|
|
/// specialised input sources, or for applications that use URI types other than URLs.
|
|
///
|
|
/// The application can also use this interface to redirect system identifiers to local
|
|
/// URIs or to look up replacements in a catalog (possibly by using the public identifier).
|
|
{
|
|
public:
|
|
virtual InputSource* resolveEntity(const XMLString* publicId, const XMLString& systemId) = 0;
|
|
/// Allow the application to resolve external entities.
|
|
///
|
|
/// The parser will call this method before opening any external entity except the
|
|
/// top-level document entity. Such entities include the external DTD subset and
|
|
/// external parameter entities referenced within the DTD (in either case, only
|
|
/// if the parser reads external parameter entities), and external general entities
|
|
/// referenced within the document element (if the parser reads external general entities).
|
|
/// The application may request that the parser locate the entity itself, that it use an
|
|
/// alternative URI, or that it use data provided by the application (as a character or
|
|
/// byte input stream).
|
|
///
|
|
/// Application writers can use this method to redirect external system identifiers to
|
|
/// secure and/or local URIs, to look up public identifiers in a catalogue, or to read an
|
|
/// entity from a database or other input source (including, for example, a dialog box).
|
|
/// Neither XML nor SAX specifies a preferred policy for using public or system IDs to resolve
|
|
/// resources. However, SAX specifies how to interpret any InputSource returned by this method,
|
|
/// and that if none is returned, then the system ID will be dereferenced as a URL.
|
|
///
|
|
/// If the system identifier is a URL, the SAX parser must resolve it fully before reporting it to
|
|
/// the application.
|
|
///
|
|
/// Note that publicId maybe null, therefore we pass a pointer rather than a reference.
|
|
|
|
virtual void releaseInputSource(InputSource* pSource) = 0;
|
|
/// This is a non-standard extension to SAX!
|
|
/// Called by the parser when the input source returned by ResolveEntity is
|
|
/// no longer needed. Should free any resources used by the input source.
|
|
|
|
protected:
|
|
virtual ~EntityResolver();
|
|
};
|
|
|
|
|
|
} } // namespace Poco::XML
|
|
|
|
|
|
#endif // SAX_EntityResolver_INCLUDED
|