context Property

[Script]

Script Syntax

var objXMLDOMNode = objXMLDOMSelection.context;
objXMLDOMSelection.context = objXMLDOMNode;

Example

The following script example shows what is contained in the context of a selection after a query is executed. It also shows that the selection is reset when this property is changed.

var xmlDoc = new ActiveXObject("Msxml2.DOMDocument.5.0");
var selection;
xmlDoc.loadXML("<Customer>Microsoft</Customer>");
xmlDoc.setProperty("SelectionLanguage", "XPath");
selection = xmlDoc.selectNodes("//Customer");
alert(selection.context.xml);

The selection.context.xml contains "<Customer>Microsoft</Customer>"; selection.length = 1.

xmlDoc.loadXML("<new>none</new>");
if (xmlDoc.parseError.errorCode <> 0) {
   var myErr = xmlDoc.parseError;
   alert("You have error " + myErr.reason);
} else {
   alert(selection.context.xml);
}

The selection.context.xml contains "<new>none</new>"; selection.length = 0.

[Visual Basic]

Visual Basic Syntax

Set objXMLDOMNode = objXMLDOMSelection.context
objXMLDOMSelection.context = objXMLDOMNode

Example

The following Microsoft® Visual Basic® example shows what is contained in the context of a selection after a query is executed. It also shows that the selected set is reset when this property is changed.

Dim xmlDoc As New Msxml2.DOMDocument50
Dim selection As Msxml2.IXMLDOMSelection

xmlDoc.loadXML ("<Customer>Microsoft</Customer>")
xmlDoc.setProperty "SelectionLanguage", "XPath"
Set selection = xmlDoc.selectNodes("//Customer")
MsgBox selection.context.xml

The selection.context.xml contains "<Customer>Microsoft</Customer>"; selection.length = 1.

xmlDoc.loadXML ("<new>none</new>")
If (xmlDoc.parseError.errorCode <> 0) Then
   Dim myErr
   Set myErr = xmlDoc.parseError
   MsgBox("You have error " & myErr.reason)
Else
   MsgBox selection.context.xml
End If

The selection.context.xml contains "<new>none</new>"; selection.length = 0.

[C/C++]

C/C++ Syntax

HRESULT get_context(IXMLDOMNode ** ppNode);
HRESULT putref_context(IXMLDOMNode * pNode);

Parameters

ppNode [out, retval]

The subtree to apply the pattern to.

pNode [in]

The subtree to apply the pattern to.

C/C++ Return Values

S_OK

The value returned if the method is successful.

S_FALSE (for get_context only)

The value returned if the context is invalid.

E_INVALIDARG (for get_context only)

The value returned if the input argument is Null.

E_FAIL (for putref_context only)

The value returned if a node with a different threading model is provided.

Example

The following C/C++ example shows what is contained in the context property after selectNodes is executed.

#import "msxml5.dll"
using namespace MSXML2;

#define CHECK_AND_RELEASE(pInterface)  \
if(pInterface) \
   {\
pInterface->Release();\
pInterface = NULL;\
   }\

#define RELEASE(pInterface)  \
   {\
pInterface->Release();\
pInterface = NULL;\
   }\

BOOL DOMSelectionContextDemo()
{
   BOOL bResult = FALSE;
   short sResult = FALSE;
   IXMLDOMSelection *pIXMLDOMSelection=NULL;
   IXMLDOMNode *pIXMLDOMNode=NULL;
   IXMLDOMDocument2 *pIXMLDOMDocument2=NULL;
   HRESULT hr;
   BSTR bstrValue;

   try
   {
      hr=CoCreateInstance(CLSID_DOMDocument, NULL, CLSCTX_SERVER, 
         IID_IXMLDOMDocument2, (LPVOID*)(&pIXMLDOMDocument2));
      SUCCEEDED(hr) ? 0 : throw hr;

      if(pIXMLDOMDocument2)
      {
         hr=pIXMLDOMDocument2->put_async(VARIANT_FALSE);
         if(SUCCEEDED(hr))
         {
            hr=pIXMLDOMDocument2->load(_variant_t( 
               _T("d:\\inetpub\\wwwroot\\samplexml.xml")), &sResult);
            if(SUCCEEDED(hr) && (sResult==VARIANT_TRUE))
            {
               hr=pIXMLDOMDocument2->selectNodes( 
               _T("*/BOOK[TITLE='Lover Birds']"),
               (IXMLDOMNodeList**)&pIXMLDOMSelection);
               if(SUCCEEDED(hr))
               {
                  if(SUCCEEDED(hr) && pIXMLDOMSelection)
                  {
                     hr=pIXMLDOMSelection->get_context(&pIXMLDOMNode);
                     if(SUCCEEDED(hr) && pIXMLDOMNode)
                     {
                        hr=pIXMLDOMNode->get_xml(&bstrValue);
                        if(SUCCEEDED(hr))
                           ::MessageBox(NULL, bstrValue, _T("Current 
                              Selection Context"), MB_OK);
                        bResult=TRUE;
                        RELEASE(pIXMLDOMNode);
                     }
                     RELEASE(pIXMLDOMSelection);
                  }
               }
            }
         }
         RELEASE(pIXMLDOMDocument2);
      }
   }
   catch(...)
   {
      CHECK_AND_RELEASE(pIXMLDOMNode);
      CHECK_AND_RELEASE(pIXMLDOMSelection);
      CHECK_AND_RELEASE(pIXMLDOMDocument2);
      DisplayErrorToUser();
   }
   return bResult;
}

Data File: d:\\inetpub\\wwwroot\\samplexml.xml

<?xml version='1.0'?>
<COLLECTION xmlns:dt="urn:schemas-microsoft-com:datatypes">
   <DATE dt:dt="datetime">1998-10-13T15:56:00</DATE>
   <BOOK>
      <TITLE>Lover Birds</TITLE>
      <AUTHOR>Cynthia Randall</AUTHOR>
      <PUBLISHER>Lucerne Publishing</PUBLISHER>
   </BOOK>
   <BOOK>
      <TITLE>The Sundered Grail</TITLE>
      <AUTHOR>Eva Corets</AUTHOR>
      <PUBLISHER>Lucerne Publishing</PUBLISHER>
   </BOOK>
</COLLECTION>

Output (in a message box)

<?xml version='1.0'?>
<COLLECTION xmlns:dt="urn:schemas-microsoft-com:datatypes">
   <DATE dt:dt="datetime">1998-10-13T15:56:00</DATE>
   <BOOK>
      <TITLE>Lover Birds</TITLE>
      <AUTHOR>Cynthia Randall</AUTHOR>
      <PUBLISHER>Lucerne Publishing</PUBLISHER>
   </BOOK>
   <BOOK>
      <TITLE>The Sundered Grail</TITLE>
      <AUTHOR>Eva Corets</AUTHOR>
      <PUBLISHER>Lucerne Publishing</PUBLISHER>
   </BOOK>
</COLLECTION>