Lookup Data From an XML Document

Category:

ASP, HTML and XML

Type:

Snippets

Difficulty:

Beginning

Author: Andrew Park

Version Compatibility: Visual Basic 6

More information:

This is an exmaple of how you can search the xml document and find the element of data you want from the xml document. A reference to Microsoft's XML object is required.

To make the example work, save the XML at the bottom to a file called C:\testxml.xml. Then call the function like this:

MsgBox GetID(1, "true", "commercial")

Of course, you should use this as a learning example to develop your own lookups because the data in this particular example won't apply in your case.

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
' (None)

Code:

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' This example shows you how you can load the xml document and
' extract the data you want from the xml.
'
' Jan 25, 2001

Private Function GetID(intBranch As Integer, strBeacon As _
   String, strBureauType As String) As String

Dim objDom As DOMDocument
   Dim intCount As Integer
   Dim objElement As IXMLDOMElement
   
   Dim strClient As String
   Dim strUser As String
   Dim strPassword As String

strClient = ""
   strUser = ""
   strPassword = ""
   
   ' Loads testxml document from hard drive onto the memory.
   Set objDom = New DOMDocument
   objDom.async = False
   objDom.Load ("c:\testxml.xml")
   Set objElement = objDom.documentElement
   
   ' If the intBranch number is greater than the
   ' branch information the xml holds "Branch ID invalid"
   ' message is displayed.
   If (intBranch - 1) >= objElement.childNodes.length Then
      MsgBox ("Branch ID invalid")
   Else
      
      ' Re-load objDom so the objDom now has the subset of
      ' xml.  Branch is root of the xml.
      objDom.loadXML _
            (objElement.childNodes.Item(intBranch - 1).xml)
      Set objElement = objDom.documentElement
            
      ' Loop through the selected branch section of the xml.
      ' If the nodename of the childnode matches the bureau
      ' type and if the first attribute matches the beacon
      ' type, then objdom now becomes the xml with the root
      ' id.
      For intCount = 0 To (objElement.childNodes.length - 1)
        If UCase(objElement.childNodes.Item(intCount).nodeName) _
              = UCase(strBureauType) Then
 
           If UCase(objElement.childNodes.Item _
             (intCount).Attributes.Item(0).Text) = _
                     UCase(strBeacon) Then
 
              objDom.loadXML _
                  (objElement.childNodes.Item(intCount).xml)
 
           End If
         End If

Next
      ' Now we have the final xml subnet we want.
      ' we can assign the clientid, userid and password.
      On Error GoTo ErrorHandler
      Set objElement = objDom.documentElement
      strClient = _
        objElement.childNodes.Item(0).Attributes.Item(0).Text
      strUser = _
         objElement.childNodes.Item(0).Attributes.Item(1).Text
      strPassword = _
         objElement.childNodes.Item(0).Attributes.Item(2).Text
   End If
   ' display results.

GetID = strClient & ", " & strUser & ", " & _
         strPassword
ErrorHandler:
    Set objDom = Nothing
    Set objElement = Nothing
End Function

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' Sample XML document.  This document is saved as testxml.xml
' and is saved in the c:\ drive.
'
'<testxml>
'   <branch id="1">
'      <consumer beacon="false">
'         <id clientid="client001" userid="consbr1" password="stuff"/>
'      </consumer>
'      <consumer beacon = "true">
'         <id clientid="client001" userid="consbr1b" password="beacon"/>
'      </consumer>
'      <commercial beacon="false">
'         <id clientid="client001" userid="commbr1" password="salad"/>
'      </commercial>
'      <commercial beacon="true">
'         <id clientid="client001" userid="commbr1b" password="fkdls"/>
'      </commercial>
'   </branch>
'   <branch id="2">
'      <consumer beacon="false">
'         <id clientid="client002" userid="userid" password="password"/>
'      </consumer>
'      <consumer beacon = "true">
'         <id clientid="client002" userid="userid" password="password"/>
'      </consumer>
'      <commercial beacon="false">
'         <id clientid="client002" userid="userid" password="password"/>
'      </commercial>
'      <commercial beacon="true">
'         <id clientid="client002" 'userid="userid" password="password"/>
'      </commercial>
'   </branch>
'   <branch id="3">
'      <consumer beacon="false">
'         <id clientid="client003" userid="userid" password="password"/>
'      </consumer>
'      <consumer beacon = "true">
'         <id clientid="client003" userid="userid" password="password"/>
'      </consumer>
'      <commercial beacon="false">
'         <id clientid="client003" userid="userid" password="password"/>
'      </commercial>
'      <commercial beacon="true">
'         <id clientid="client003" userid="userid" password="password"/>
'      </commercial>
'  </branch>
'</testxml>
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' This procedure gets branch number (integer), beacon type (string)
' and bureau type (string) and finds the appropriate clientid,
' userid and password.
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