Using Visual Basic ® With The MSXML Parser Ken Spencer Vice President 32X Corporation

Cross-Platform Interop Application Data Comm Windows DNA 2000 Other Platforms Application Framework implementation Data Comm Core Standards Application Schemas FrameworksPlatform/Tools Solutions and Applications Platform/Tools Framework implementation

The Microsoft ® XML Engine Freely distributed Freely distributed  msdn.microsoft.com/downloads/webtechn ology/xml/msxml.asp Fast parser Fast parser Great for creating and reading XML data Great for creating and reading XML data  Files  Streams

Instantiating From ASP From ASP Dim xmlDoc Dim sXML Set xmlDoc = CreateObject("microsoft.xmldom") From Visual Basic From Visual Basic Dim xDoc As MSXML.DOMDocument Set xDoc = New MSXML.DOMDocument

Loading XML Data Stream Data Stream Data sXML = txtXML xmlDoc.async = False xmlDoc.loadXML (sXML) File Data File DataxmlDoc.Load("f:\data\customer01.xml")

Asynchronous Loading Async Property Async Property  Defaults to True  Requires checking readyState property  Returns 0 – 4  4 indicates load complete Setting Async Setting Async  xmlDoc.async = False  Sets to false, loading will be synchronous

Retrieving XML Data Extract the XML Extract the XML  txtOutput = xmlDoc.xml txtOuput txtOuput  Contains entire XML stream

Working With Nodes Understand NodeType property Understand NodeType property Node Type Example NODE_ELEMENT The Offspring The Offspring NODE_ATTRIBUTE The Offspring > The Offspring > NODE_TEXT The Offspring The Offspring NODE_PROCESSING_INSTRUCTI ON NODE_DOCUMENT_TYPE

Working With Nodes Retrieve elements by name Retrieve elements by name  getElementsByTagName Walk through children Walk through children  IXMLDOMNodeList  Check out DisplayNode

Searching For Nodes Search for node by name Search for node by name  Build nodelist  Use NextMode method to walk list  See cmdNextNode_Click

Extracting Attributes Use Attributes property Use Attributes property  Returns list of attributes  Returned in XMLDOMNamedNodeMap object  For nodeTypes of:  NODE_ELEMENT  NODE_ENTITY  NODE_NOTATION  getNamedItem will return attribute text  See cmdGetBookAttribute_Click

Creating XML Create an empty document Create an empty document  xmlDoc.loadXML " "  Loads the parser  Document is empty  Has one blank node (required)  Use appendChild to add nodes  Extract XML with XML property  See cmdCreateNode_Click

Where Now? Tip of the iceberg Tip of the iceberg XML is moving everywhere XML is moving everywhere MSXML MSXML  Works with XSL stylesheets and schmas  Much more under the hood References References  