IXMLDOMSchemaCollection/XMLSchemaCache
Used by the schemas
and namespaces
properties of the IXMLDOMDocument2
interface.
The following code shows how to create XMLSchemaCache
objects in Microsoft® JScript®.
var cache = new ActiveXObject("Msxml2.XMLSchemaCache.5.0");
The following code shows how to create XMLSchemaCache
objects in Microsoft® Visual Basic® Scripting Edition (VBScript).
Dim cache Set cache = CreateObject("Msxml2.XMLSchemaCache.5.0");
Example
The following example shows how to build a reusable schema cache.
- Load a document that references schemas through x-schema.
var xmldoc = new ActiveXObject("Msxml2.DOMDocument.5.0"); xmldoc.async = false; xmldoc.load("http://myserver/mydata.xml"); if (xmlDoc.parseError.errorCode <> 0) { var myErr = xmlDoc.parseError; alert("You have error " + myErr.reason); }
- Build a cache from the schemas loaded by your document.
var cache = new ActiveXObject("Msxml2.XMLSchemaCache.5.0"); cache.addCollection(xmldoc.namespaces);
- Now you can use this cache in the
load
method of another document.var xmldoc2 = new ActiveXObject("Msxml2.DOMDocument.5.0"); xmldoc2.async = false; xmldoc2.schemas = cache; xmldoc2.load("http://myserver/newdata.xml"); if (xmlDoc.parseError.errorCode <> 0) { var myErr = xmlDoc.parseError; alert("You have error " + myErr.reason); }
The
Xmldoc2
object will load much faster because the schemas are cached.
The IXMLDOMSchemaCollection
implementation in MSXML 2.6 and 3.0 also supports the following interface through QueryInterface
.
Interface | Usage |
---|---|
IID_EnumVARIANT |
Returns an IEnumVARIANT implementation, so that the collection can be used in Microsoft® Visual Basic® For Each statements. Enumerates the namespace Uniform Resource Identifiers (URIs). |
Return Values
- E_FAIL
- The attempt to modify a read-only object failed for one of the following reasons: argument is not a valid schema; invalid namespace URI; or document is not ready.
- E_INVALIDARG
- The parameter is incorrect.
- E_OUTOFMEMORY
- Out of memory.
- E_POINTER
- Invalid pointer.
Example
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 DOMDocument2nameSpaces() { BOOL bResult = FALSE; short sResult = FALSE; IXMLDOMElement *pIXMLDOMElement=NULL; IXMLDOMSchemaCollection *pIXMLDOMSchemaCollection=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\\samplexmldtd.xml")), &sResult); if(SUCCEEDED(hr) && (sResult==VARIANT_TRUE)) { hr=pIXMLDOMDocument2->get_namespaces( &pIXMLDOMSchemaCollection); if(SUCCEEDED(hr)) { LONG uLength; bResult=TRUE; hr=pIXMLDOMSchemaCollection->get_length(&uLength); if(SUCCEEDED(hr)) { for(int iIndex=0; iIndex < uLength; iIndex++) { hr=pIXMLDOMSchemaCollection->get_namespaceURI( iIndex, &bstrValue); if(SUCCEEDED(hr)) ::MessageBox(NULL, bstrValue, _T("Namespace"), MB_OK); } } } } } RELEASE(pIXMLDOMDocument2); } } catch(...) { CHECK_AND_RELEASE(pIXMLDOMDocument2); DisplayErrorToUser(); } return bResult; }
d:\\inetpub\\wwwroot\\samplexmldtd.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> </COLLECTION>
Output (in a message box)
urn:schemas-microsoft-com:datatypes
Remarks
The IXMLDOMSchemaCollection
/XMLSchemaCache
object is free-threaded and can be used in multiple documents at the same time. The XML Schema document that is sent to the schema collection is cloned, and the XML Schema document remains writable. Any changes that occur in the XML Schema file after it is stored in the schema cache are not reflected in its cloned image. A single schema cache can be added to multiple schema collections, due to the creation of the cloned image.
Note In MSXML, "free-threaded" means ThreadingModel='Both'
, and cross-thread marshalling is supported.
Versioning
MSXML 2.6 and later
Requirements
Implementation: msxml5.dll, msxml2.lib
Header and IDL files: msxml2.h, msxml2.idl
Version-Dependent ProgID: Msxml2.XMLSchemaCache.5.0
Version-Dependent CLSID: 88d969c2-f192-11d4-a65f-0040963251e5
To view reference information for Visual Basic, C/C++, or Script only, click the Language Filter button in the upper-left corner of the page.
See Also
IXMLDOMSchemaCollection/XMLSchemaCache Members | IXMLDOMDocument2