Implementing COM Interfaces with C++0x Variadic Templates

#pragma once

/*
 * Copyright (c) 2011, KO Software (official@ko-sw.com)
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     - All original and modified versions of this source code must include the
 *       above copyright notice, this list of conditions and the following
 *       disclaimer.
 *
 *     - The name of KO Software may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY KO SOFTWARE ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT WILL KO SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


#include "sdk_ComObject.h"

//! If Visual Studio 2010 supported variadic templates and we wanted to use
//! it in our works instead of GCC, the below line would need to be changed to
//! #include <msxml2.h>
//! where everything is already declared properly.
#if _MSC_VER > 1100
#  include <msxml2.h>
#else
#  include "msxml.h"
#endif


////////////////////////////////////////////////////////////////////////////////

class XmlHandler :

#if (SUPPORTED_CPP0X != 0)
	public ComEntryV<ISAXContentHandler>
#else
	public ComEntry1<ISAXContentHandler>
#endif

{
private:
	std::vector<std::wstring> myStack;	//!< Stack of tag names being parsed
	std::wstring myCurVersion;


// Interface
public:
  const std::wstring & GetParsedCurrentVersion() const
    { return myCurVersion; }


// ISAXContentHandler members
protected:
	STDMETHODIMP putDocumentLocator
		(
			ISAXLocator *    /* theVal               */
		)
	{ return S_OK; }


	STDMETHODIMP startPrefixMapping
		(
			LPCWSTR          /* thePrefix            */,
			int              /* theNumCharsPrefix    */,
			LPCWSTR          /* theUri               */,
			int              /* theNumCharsUri       */
		)
	{ return S_OK; }


	STDMETHODIMP endPrefixMapping
		(
			LPCWSTR          /* thePrefix            */,
			int              /* theNumCharsPrefix    */
		)
	{ return S_OK; }


	STDMETHODIMP ignorableWhitespace
		(
			LPCWSTR          /* theWhsp              */,
			int              /* theNumChars          */
		)
	{ return S_OK; }


	STDMETHODIMP processingInstruction
		(
			LPCWSTR          /* theTarget            */,
			int              /* theNumCharsTarget    */,
			LPCWSTR          /* theData              */,
			int              /* theNumCharsData      */
		)
	{ return S_OK; }


	STDMETHODIMP skippedEntity
		(
			LPCWSTR          /* theName              */,
			int              /* theNumCharsName      */
		)
	{ return S_OK; }


	STDMETHODIMP startDocument()
	{ return S_OK; }


	STDMETHODIMP endDocument()
	{ return S_OK; }


	STDMETHODIMP startElement
		(
			LPCWSTR          /* theUri               */,
			int              /* theNumCharsUri       */,
			LPCWSTR             theLocalName           ,
			int                 theNumCharsLocalName   ,
			LPCWSTR          /* theQualName          */,
			int              /* theNumCharsQualName  */,
			ISAXAttributes * /* theAttribs           */
		)
	{
		std::wstring aName(theLocalName, theLocalName + theNumCharsLocalName);
		myStack.push_back(aName);

		return S_OK;
	}


	STDMETHODIMP endElement
		(
			LPCWSTR          /* theUri               */,
			int              /* theNumCharsUri       */,
			LPCWSTR             theLocalName           ,
			int                 theNumCharsLocalName   ,
			LPCWSTR          /* theQualName          */,
			int              /* theNumCharsQualName  */
		)
	{
		std::wstring aName(theLocalName, theLocalName + theNumCharsLocalName);

		if (myStack.back() != aName)
			return E_FAIL;

		myStack.pop_back();
		return S_OK;
	}


	STDMETHODIMP characters
		(
			LPCWSTR             theString              ,
			int                 theNumChars
		)
	{
		if (myStack.size() == 3)
			if ( myStack[0] == L"XML_DIZ_INFO" &&
					 myStack[1] == L"Program_Info" &&
					 myStack[2] == L"Program_Version" )
			{
				myCurVersion += std::wstring(theString, theString + theNumChars);
			}

		return S_OK;
	}
};