Source: loadDOM.cpp

 

This C/C++ source code performs the following steps:

  1. Creates an XML DOM object (pXMLDom) and sets it to synchronous mode.

  2. Calls the load method on pXMLDom, specifying the path to stocks.xml.

To add loadDOM.cpp to the project

  1. Create a new C++ source file. For detailed instructions on how to do this, see Set Up My Visual C++ Project. Name the new file loadDOM.cpp.

  2. Copy the C/C++ source code above, and paste it into the source file you just created.

  3. Next, we'll add the resource file, stocks.xml.

C/C++ Source File (loadDom.cpp)

// LoadDOM.cpp : Defines the entry point for the console application.
//

#include <stdio.h>
#include <tchar.h>
#import <msxml6.dll> raw_interfaces_only

// Macro that calls a COM method returning HRESULT value.
#define CHK_HR(stmt)        do { hr=(stmt); if (FAILED(hr)) goto CleanUp; } while(0)

// Macro to verify memory allcation.
#define CHK_ALLOC(p)        do { if (!(p)) { hr = E_OUTOFMEMORY; goto CleanUp; } } while(0)

// Macro that releases a COM object if not NULL.
#define SAFE_RELEASE(p)     do { if ((p)) { (p)->Release(); (p) = NULL; } } while(0)

// Helper function to create a VT_BSTR variant from a null terminated string. 
HRESULT VariantFromString(PCWSTR wszValue, VARIANT &Variant)
{
    HRESULT hr = S_OK;
    BSTR bstr = SysAllocString(wszValue);
    CHK_ALLOC(bstr);
    
    V_VT(&Variant)   = VT_BSTR;
    V_BSTR(&Variant) = bstr;

CleanUp:
    return hr;
}

// Helper function to create a DOM instance. 
HRESULT CreateAndInitDOM(IXMLDOMDocument **ppDoc)
{
    HRESULT hr = CoCreateInstance(__uuidof(MSXML2::DOMDocument60), NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(ppDoc));
    if (SUCCEEDED(hr))
    {
        // these methods should not fail so don't inspect result
        (*ppDoc)->put_async(VARIANT_FALSE);  
        (*ppDoc)->put_validateOnParse(VARIANT_FALSE);
        (*ppDoc)->put_resolveExternals(VARIANT_FALSE);
    }
    return hr;
}

void loadDOM()
{
    HRESULT hr = S_OK;
    IXMLDOMDocument *pXMLDom=NULL;
    IXMLDOMParseError *pXMLErr = NULL;

    BSTR bstrXML = NULL;
    BSTR bstrErr = NULL;
    VARIANT_BOOL varStatus;
    VARIANT varFileName;
    VariantInit(&varFileName);
    
    CHK_HR(CreateAndInitDOM(&pXMLDom));    
    
    // XML file name to load
    CHK_HR(VariantFromString(L"stocks.xml", varFileName));
    CHK_HR(pXMLDom->load(varFileName, &varStatus));
    if (varStatus == VARIANT_TRUE)
    {
        CHK_HR(pXMLDom->get_xml(&bstrXML));
        printf("XML DOM loaded from stocks.xml:\n%S\n", bstrXML);
    }
    else
    {
        // Failed to load xml, get last parsing error
        CHK_HR(pXMLDom->get_parseError(&pXMLErr));
        CHK_HR(pXMLErr->get_reason(&bstrErr));
        printf("Failed to load DOM from stocks.xml. %S\n", bstrErr);
    }

CleanUp:
    SAFE_RELEASE(pXMLDom);
    SAFE_RELEASE(pXMLErr);
    SysFreeString(bstrXML);
    SysFreeString(bstrErr);
    VariantClear(&varFileName);
}

int _tmain(int argc, _TCHAR* argv[])
{
    HRESULT hr = CoInitialize(NULL);
    if(SUCCEEDED(hr))
    {
        loadDOM();
        CoUninitialize();
    }

    return 0;

}