asked on

Retrieve values from an xml file using c++

i am not able to retrieve the values from the xml file .
How do u get the value of a specific node ?
My xml file looks like this

<?XML version="1.0">
<values>
<val>
<value1>2</value1>
<value2>4</value2>
</val>
</values>
Now i want to retrieve the value of the value1 node and i have specified in the code

VARIANT *Name;
CComBSTR str1("value1");

node->selectSingleNode(_bstr_t(str1.Copy ()));

node->get_text (&nodeName);
printf("The text is %S",nodeName);

But it gives me the value of both the nodes together i.e 2 and 4
i want to retrieve the values based on the tagnames ie the text for value1 is 2 and the text for value2 is 4.
how can you do this?

LDC

What program are you using to parse the xml?

ASKER CERTIFIED SOLUTION

talik

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sajana

ASKER

node is a interface pointer and i am using namespaces also.

xml::IXMLDOMNode* node;
CComBSTR str1("value1");

node->selectSingleNode(_bstr_t(str1.Copy ()));

node->get_text (&nodeName);
printf("The text is %S",nodeName);
//

after i modified my code as
node = node->selectSingleNode (...);
i get a runtime error

It really does not help
Please anyone could guide me as to how to extract the value from a node based on its tagname .

Thanks

Regards
Sajana

talik

Hi Sajana,

It would adwise to use #import for msxml.dll and use smart pointers.

Then, you code should look like this:
(this code compiles and gives right result for me)

#import "msxml.dll" rename_namespace ("xml")

void CTxmlDlg::OnButton1()
{
      OleInitialize (NULL);

      try
      {
            xml::IXMLDOMDocumentPtr pDoc (__uuidof (xml::DOMDocument));
            pDoc->loadXML ("<values><val><value1>2</value1><value2>4</value2></val></values>");

            xml::IXMLDOMNodePtr pRootNode = pDoc->selectSingleNode (_bstr_t (_T ("values")));
            xml::IXMLDOMNodePtr pValNode = pRootNode->selectSingleNode (_bstr_t (_T ("val")));
            xml::IXMLDOMNodePtr pValue1Node = pValNode->selectSingleNode (_bstr_t (_T ("value1")));
            _bstr_t text = pValue1Node->Gettext ();

      }
catch (_com_error err)
{

}
      catch (...)
      {

      }

      OleUninitialize ();
}

You can call selectSingleNode for root with a query "values/val/value1" instead.

talik

Additional comment:
If you want to select a single node ANYWHERE in document you should use double slash before the node name.

For example, you can change my exeample in the following way:

instead of

xml::IXMLDOMNodePtr pRootNode = pDoc->selectSingleNode (_bstr_t (_T ("values")));
xml::IXMLDOMNodePtr pValNode = pRootNode->selectSingleNode (_bstr_t (_T ("val")));
xml::IXMLDOMNodePtr pValue1Node = pValNode->selectSingleNode (_bstr_t (_T ("value1")));

you can write:
xml::IXMLDOMNodePtr pValue1Node = pDoc->selectSingleNode (_bstr_t (_T ("//value1")));

sajana

ASKER

Talik -

Thanks a lot .It really works.

You guys are simply great.

I have already graded you for your answer and also given you points for the same.

Thanks once again

Bye

Sajana