how to find nodes in xml file using xpath

[milecimm]

Hi

I have a textbox that people would need to use to search a xml file. If a record is found with that worrd as keyword then the item is returned. I need to return ID, for example, but I dont seem to find the way to do this. Could you help? Thanks. This is what I have but I get "Object reference not set to an instance of an object."

Dim d() As String
        Dim j As Integer
        d = TextBox1.Text.Split(" ")
        Dim xpathexpression As String = ""
        For j = 0 To d.GetUpperBound(0)
         xpathexpression = xpathexpression & "contains(CONTRACTKEYWORDS,'" & d(j) & "')"
         
            If j < d.GetUpperBound(0) Then
                xpathexpression = xpathexpression & " or "
            End If
        Next

Dim xdoc As New XPathDocument(AppDomain.CurrentDomain.BaseDirectory + "/testxml.xml")

        Dim nav As XPathNavigator = xdoc.CreateNavigator()
 Dim nodes As XPathNodeIterator = nav.Select("/CONTRACTS/CONTRACT/*[" & xpathexpression & "]")
 tr += "<tr><td>" & nav.SelectSingleNode("ID").Value & "</td>"
For Each node As XPathNavigator In nodes
 tr += "<td>" & node.SelectSingleNode("CONTRACTKEYWORDS").Value & "</td></tr>"
Next

Dim th As String = "<th>Commodity</th><th>Name</th><th>Supplier</th><th>Name</th>"
        div1.InnerHtml = ("<table class='datatable1'>" & th) + tr & "</table>"

My xml is:

<CONTRACTS>
  <CONTRACT>
   <ID>779</ID>
   <NAME>ContractName779</NAME>

     <STARTDATE>1/8/2005</STARTDATE>
     <ENDDATE>31/7/2008</ENDDATE>
     <COMMODITIES>
       <COMMODITY>
         <COMMODITYCODE>CHEM</COMMODITYCODE>
         <COMMODITYNAME>Chemicals</COMMODITYNAME>
       </COMMODITY>
     </COMMODITIES>
    <SUPPLIERS>
      <SUPPLIER>
        <SUPPLIERID>1298</SUPPLIERID>
        <SUPPLIERNAME>Supplier name</SUPPLIERNAME>
        </SUPPLIER>
      </SUPPLIERS>
    <CONTRACTTERMS>
     <CONTRACTKEYWORDS>Chemistry, Engineering, Chemical</CONTRACTKEYWORDS>
      </CONTRACTTERMS>
  </CONTRACT>
</CONTRACTS>

[Dormilich]

sorry, can’t help with that programming language.

[jkmyoung]

You're filtering on child CONTRACTKEYWORD S. However in your xml you have:

 <CONTRACTTERMS> 
     <CONTRACTKEYWORDS>

You need to be filtering on CONTRACTTERMS/CONTRACTKEYWORD S,
And selecting it too when outputting values.

xpathexpression = xpathexpression & "contains(CONTRACTTERMS/CONTRACTKEYWORDS,'" & d(j) & "')" 
...
tr += "<td>" & node.SelectSingleNode("CONTRACTTERMS/CONTRACTKEYWORDS").Value & "</td></tr>"

[milecimm]

Hi, thanks for your help.

My problem is how to get the Contract ID, name, etc as they are way back my path. How Can I get:
CONTRACTS/CONTRACT/CONTRACTID
CONTRACTS/CONTRACT/NAME
CONTRACTS/CONTRACT/COMMODITIES/COMMODITY/COMMODITYNAME
CONTRACTS/CONTRACT/SUPPLIERS/SUPPLIER/SUPPLIERNAME

WHERE
CONTRACTS/CONTRACT/CONTRACTTERMS/CONTRACTKEYWORD S
ARE
..whatever...

Many thanks...

[jkmyoung]

Context. What you are selecting:
nav.Select("/CONTRACTS/CONTRACT/*["
-Contract nodes.

For the rest of the nodes, you have to think about their position relative to the CONTRACT node. Pretty much just remove /CONTRACTS/CONTRACT/ from the front of the absolute xpath. eg:
ID
NAME
COMMODITIES/COMMODITY/COMMODITYNAME
SUPPLIERS/SUPPLIER/SUPPLIERNAME

[milecimm]

Hi
Thanks for your help. It worked.