selectNodes Method
Applies the specified pattern-matching operation to this node's context and returns the list of matching nodes as IXMLDOMNodeList
.
JScript Syntax
var objXMLDOMNodeList = oXMLDOMNode.selectNodes(expression);
Parameters
expression
A string specifying an XPath expression.
Return Value
An object. Returns the collection of nodes selected by applying the given pattern-matching operation. If no nodes are selected, returns an empty collection.
Example
The following script example creates an IXMLDOMNodeList
object containing the nodes specified by the expression parameter (for example, all the <xsl:template>
nodes in an XSLT style sheet). It then displays the number of nodes contained in the node list.
Note
You can use hello.xsl in the Hello World! (XSLT) topic topic to run this sample code.
var xmlDoc = new ActiveXObject("Msxml2.DOMDocument.6.0");
var objNodeList;
xmlDoc.async = false;
xmlDoc.load("hello.xsl");
if (xmlDoc.parseError.errorCode != 0) {
var myErr = xmlDoc.parseError;
WScript.Echo("You have error " + myErr.reason);
} else {
xmlDoc.setProperty("SelectionNamespaces", "xmlns:xsl='http://www.w3.org/1999/XSL/Transform'");
xmlDoc.setProperty("SelectionLanguage", "XPath");
objNodeList = xmlDoc.documentElement.selectNodes("//xsl:template");
WScript.Echo(objNodeList.length);
}
Output
2
C/C++ Syntax
HRESULT selectNodes(
BSTR expression,
IXMLDOMNodeList **resultList);
Parameters
expression[in]
A string specifying an XPath expression.
resultList[out, retval]
The list of nodes selected by applying the given pattern-matching operation. If no nodes are selected, returns an empty node list.
Return Values
S_OK
The value returned if successful.
E_INVALIDARG
The value returned if the resultList
parameter is Null.
Example
The following Microsoft Visual C++ example creates an IXMLDOMNodeList
object containing the nodes specified by the expression parameter (for example, all the <xsl:template>
nodes in an XSLT stylesheet). It then displays the number of nodes contained in the node list.
XpathSelectNodes.cpp
#include �msxml6.h�
using namespace MSXML2;
void dump_com_error(_com_error &e);
int main(int argc, char* argv[])
{
CoInitialize(NULL);
try{
IXMLDOMDocument2Ptr pXMLDoc = NULL;
HRESULT hr = pXMLDoc.CreateInstance(__uuidof(DOMDocument60));
// Set parser property settings
pXMLDoc->async = VARIANT_FALSE;
// Load the sample XML file
hr = pXMLDoc->load("hello.xsl");
// If document does not load report the parse error
if(hr!=VARIANT_TRUE)
{
IXMLDOMParseErrorPtr pError;
pError = pXMLDoc->parseError;
_bstr_t parseError =_bstr_t("At line ")+ _bstr_t(pError->Getline())
+ _bstr_t("\n")+ _bstr_t(pError->Getreason());
MessageBox(NULL,parseError, "Parse Error",MB_OK);
return 0;
}
// Otherwise, build node list using SelectNodes
// and returns its length as console output
else
pXMLDoc->setProperty("SelectionLanguage", "XPath");
// Set the selection namespace URI if the nodes
// you wish to select later use a namespace prefix
pXMLDoc->setProperty("SelectionNamespaces",
"xmlns:xsl='http://www.w3.org/1999/XSL/Transform'");
IXMLDOMElementPtr pXMLDocElement = NULL;
pXMLDocElement = pXMLDoc->documentElement;
IXMLDOMNodeListPtr pXMLDomNodeList = NULL;
pXMLDomNodeList = pXMLDocElement->selectNodes("//xsl:template");
int count = 0;
count = pXMLDomNodeList->length;
printf("The number of <xsl:template> nodes is %i.\n", count);
}
catch(_com_error &e)
{
dump_com_error(e);
}
return 0;
}
void dump_com_error(_com_error &e)
{
printf("Error\n");
printf("\a\tCode = %08lx\n", e.Error());
printf("\a\tCode meaning = %s", e.ErrorMessage());
_bstr_t bstrSource(e.Source());
_bstr_t bstrDescription(e.Description());
printf("\a\tSource = %s\n", (LPCSTR) bstrSource);
printf("\a\tDescription = %s\n", (LPCSTR) bstrDescription);
}
Try It!
Set up a new empty project in Visual C++ for a Win32 console application.
For more information, see Set Up My Visual C++ Project.
Copy the XpathSelectNodes.cpp file and paste it in as code for a new Visual C/C++ source file in your project.
Copy the hello.xsl file from the Hello, World! (XSLT) tutorial application and paste and save it as a resource file in the same folder as your project.
Build and execute the project as a console EXE application.
Results and Output
When run successfully using the sample code and files, the application will return as standard console output the following:
The number of <xsl:template> nodes is 2.
Remarks
For more information about using the selectNodes
method with namespaces, see the setProperty Method topic.
The selectSingleNode
method is similar to the selectNodes
method, but returns only the first matching node rather than the list of all matching nodes.
IXMLDOMNodeList
is live and immediately reflects changes to the nodes that appear in the list.
This member is an extension of the World Wide Web Consortium (W3C) Document Object Model (DOM).
Note
Previously, in MSXML 3.0 and earlier versions, the selection object created by calling the selectNodes
method would gradually calculate the node-set. If the DOM tree was modified, while the selectNodes
call was still actively iterating its contents, the behavior could potentially change the nodes that were selected or returned. In MSXML 6., the node-set result is fully calculated at the time of selection. This ensures that the iteration is simple and predictable. In rare instances, this change might impact legacy code written to accommodate previous behavior.
Versioning
Implemented in: MSXML 3.0 and MSXML 6.0
See Also
Using XSLT with the DOM or SAX
selectSingleNode Method
IXMLDOMNodeList
IXMLDOMAttribute
IXMLDOMCDATASection
IXMLDOMCharacterData
IXMLDOMComment
IXMLDOMDocument-DOMDocument
IXMLDOMDocumentFragment
IXMLDOMDocumentType
IXMLDOMElement
IXMLDOMEntity
IXMLDOMEntityReference
IXMLDOMNode
IXMLDOMNotation
IXMLDOMProcessingInstruction
IXMLDOMText