XML DOM: problem using appendChild with IXMLDOMNode

Hi Everyone,

I am trying build an xml file using msxml dom object. The xml file will have a root node with a single attribute and child node. I got the root node and attribute working but having problems appending the child node to the root. I create the node with out a problem but everytime time i try to appendChild , it returns E_FAILED code.

I have used msdn's sample code (since i'm new to msxml) .. can someone take a look at my code see what I am doing wrong. The function in which I create all my xml nodes and use appendChild is called createXMLFile().

Thanks a bunch!

THE CODE:

#include "StdAfx.h"
#include "NI.h"
#include <stdlib.h>
#include <iostream.h>
#include <Windows.h>
#include <stdio.h> // for msdn functions
//include xml dom headers and libraries automatically
#import <msxml4.dll> raw_interfaces_only
using namespace MSXML2;


// Macro that calls a COM method returning HRESULT value:
#define HRCALL(a, errmsg, i) \
do { \
hr = (a); \
if (FAILED(hr)) { \
cout<<"**Failed:"<<i<<endl;\
goto clean; \
} \
} while (0)


void AddWhiteSpaceToNode(IXMLDOMDocument *pDom, BSTR bstrWs, IXMLDOMNode *pNode);
IXMLDOMDocument * DomFromCOM();
void AppendChildToParent(IXMLDOMNode *pChild, IXMLDOMNode *pParent);
VARIANT VariantString(BSTR str);
void dprintf(char *format, ...);
int createXMLFile();

void main()
{
createXMLFile();
}

//THE PROBLEM
int createXMLFile()
{

IXMLDOMDocument *pXMLDom=NULL;
IXMLDOMProcessingInstruction *pi=NULL;
IXMLDOMNode *pNode = NULL;
IXMLDOMNode *pRoot = NULL;
IXMLDOMAttribute *pAttr = NULL;
IXMLDOMNamedNodeMap *pAttrMap = NULL;
IXMLDOMElement *pElem = NULL;
IXMLDOMNode *pTempNode = NULL;
IXMLDOMElement *pe =NULL;

BSTR bstr = NULL;
BSTR bstr1 = NULL;

VARIANT var;
HRESULT hr;

_variant_t varNodeType((short)MSXML2::NODE_ELEMENT);
_variant_t varAttrType((short)MSXML2::NODE_ATTRIBUTE);
_variant_t varTemp;

CoInitialize(NULL);
VariantInit(&var);

pXMLDom = DomFromCOM();
if (!pXMLDom) goto clean;

// Create a processing instruction element.
bstr = SysAllocString(L"xml");
bstr1 = SysAllocString(L"version='1.0'");
HRCALL(pXMLDom->createProcessingInstruction(
bstr,bstr1, &pi),
"createProcessingInstruction:", 11);
AppendChildToParent(pi, pXMLDom);
pi->Release();
pi=NULL;
SysFreeString(bstr);
bstr=NULL;
SysFreeString(bstr1);
bstr1=NULL;

// Create the root element and add to xmldoc
bstr = SysAllocString(L"ns1:networkElement");
bstr1 = SysAllocString(L"http://somelink.com");
HRCALL(pXMLDom->createNode(varNodeType, bstr, bstr1, &pRoot), "", 12);
AppendChildToParent(pRoot, pXMLDom);
SysFreeString(bstr1);
bstr1 = NULL;
SysFreeString(bstr);
bstr = NULL;


// Create a "id" attribute for the <root> element, and
// assign the "annabell" character data as the attribute value.
bstr = SysAllocString(L"id");
var = VariantString(L"annabelle");
HRCALL(pXMLDom->createAttribute(bstr, &pAttr), "", 14);
HRCALL(pAttr->put_nodeTypedValue(var), "", 15);
HRCALL(pRoot->get_attributes(&pAttrMap), "", 16);
HRCALL(pAttrMap->setNamedItem(pAttr, &pRoot), "", 17);
SysFreeString(bstr);
bstr = NULL;

// Create a <node1> to hold text content.
bstr = SysAllocString(L"includelist");
bstr1= SysAllocString(L"");

HRCALL(pXMLDom->createNode(varNodeType, bstr, bstr1, &pNode),"", 19.1);
SysFreeString(bstr);
SysFreeString(bstr1);
bstr=NULL;
bstr1=NULL;
VariantClear(&var);
var.vt = NULL;

//THIS ALWAYS FAILS!!! .. WHY???
if (pRoot->appendChild(pNode, &pTempNode) == E_FAIL)
{
cout<<"Failed! :-(( "<<endl;
}
pNode->Release();
pNode=NULL;

VariantClear(&var);
var = VariantString(L"dynamDom.xml");
HRCALL(pXMLDom->save(var), "", 20);
dprintf("DOM saved to dynamDom.xml\n");
clean:
if (bstr) SysFreeString(bstr);
if (bstr1) SysFreeString(bstr1);
if (&var) VariantClear(&var);
if (pRoot) pRoot->Release();
if (pNode) pNode->Release();

CoUninitialize();
return 0;

}

//THESE METHODS COPIED DIRECTLY FROM MSDN SITE:
//http://msdn.microsoft.com/library/default.asp?url=/library/en-us/xmlsdk/htm/dom_hdi_823x.asp
// Helper function to append a whitespace text node to a
// specified element:
void AddWhiteSpaceToNode(IXMLDOMDocument* pDom,
BSTR bstrWs,
IXMLDOMNode *pNode)
{
HRESULT hr;
IXMLDOMText *pws=NULL;
IXMLDOMNode *pBuf=NULL;
HRCALL(pDom->createTextNode(bstrWs,&pws), " ", 9);
HRCALL(pNode->appendChild(pws,&pBuf)," ", 10);
clean:
if (pws) pws->Release();
pws=NULL;
if (pBuf) pBuf->Release();
pBuf=NULL;
}

// Helper function to create a DOM instance.
IXMLDOMDocument * DomFromCOM()
{
HRESULT hr;
IXMLDOMDocument *pxmldoc = NULL;

HRCALL( CoCreateInstance(__uuidof(DOMDocument40),
NULL,
CLSCTX_INPROC_SERVER,
__uuidof(IXMLDOMDocument),
(void**)&pxmldoc),
"Create a new DOMDocument", 31);

HRCALL( pxmldoc->put_async(VARIANT_FALSE),
"should never fail", 32);
HRCALL( pxmldoc->put_validateOnParse(VARIANT_FALSE),
"should never fail", 33);
HRCALL( pxmldoc->put_resolveExternals(VARIANT_FALSE),
"should never fail", 34);
HRCALL( pxmldoc->put_preserveWhiteSpace(VARIANT_TRUE),
"should never fail",35);

return pxmldoc;
clean:
if (pxmldoc)
{
pxmldoc->Release();
}
return NULL;
}

// Helper function to append a child to a parent node:
void AppendChildToParent(IXMLDOMNode *pChild, IXMLDOMNode *pParent)
{
HRESULT hr;
IXMLDOMNode *pNode=NULL;
HRCALL(pParent->appendChild(pChild, &pNode), "", 36);

clean:
if (pNode) pNode->Release();
pNode=NULL;

}

VARIANT VariantString(BSTR str)
{
VARIANT var;
VariantInit(&var);
V_BSTR(&var) = SysAllocString(str);
V_VT(&var) = VT_BSTR;
return var;
}

void dprintf(char *format, ...)
{
static char buf[1024];
va_list args;
va_start( args, format );
vsprintf( buf, format, args );
va_end( args);
OutputDebugStringA( buf);
printf("%s", buf);
}

Do u still have this problem?


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