Get linenumber and position from standard XML validation

[Radjesh Klauke]

Now, you would say that this is simple, but in this example the validator returns 2 linenumbers and positions. And guess what!? I need the first linenumber and position in the message. I can only get the last position and linenumber using the ex.Position and ex.Linenumber. See Image below.



My code:

msgbox(ex.Message.ToString & vbNewLine & "Linenumber: " & ex.LineNumber.ToString & vbNewLine & "Position: " & ex.LinePosition.ToString)

I need to get/extract Line 3, Position 10 from the error.

Anyone?

[kareninstructor]

Brute Force, see http://msdn.microsoft.com/en-us/libr...v=vs.110).aspx

Dim xmlFrag As String = "<test>" + Chr(10) & _
                        "  <proper>" + Chr(10) & _
                        "  </proper>" + Chr(10) & _
                        "  <wrong>" + Chr(10) & _
                        "  <wrong>" + Chr(10) & _
                        "  <right>" + Chr(10) & _
                        "  </right>" + Chr(10) & _
                        "</test>"

' Create the XmlNamespaceManager. 
Dim nsmgr As Xml.XmlNamespaceManager = New Xml.XmlNamespaceManager(New Xml.NameTable())

' Create the XmlParserContext. 
Dim context As Xml.XmlParserContext = New Xml.XmlParserContext(Nothing, nsmgr, Nothing, Xml.XmlSpace.None)

' Create the reader. 
Dim reader As Xml.XmlValidatingReader = New Xml.XmlValidatingReader(xmlFrag, Xml.XmlNodeType.Element, context)

Dim lineInfo As Xml.IXmlLineInfo = CType(reader, Xml.IXmlLineInfo)
Dim ErrorMessage As String = ""
If (lineInfo.HasLineInfo()) Then


    ' Parse the XML and display each node.
    Try
        While (reader.Read())
            Select Case reader.NodeType
                Case Xml.XmlNodeType.Element
                    Console.Write("{0} {1},{2}  ", reader.Depth, lineInfo.LineNumber, lineInfo.LinePosition)
                    Console.WriteLine("<{0}>", reader.Name)
                Case Xml.XmlNodeType.Text
                    Console.Write("{0} {1},{2}  ", reader.Depth, lineInfo.LineNumber, lineInfo.LinePosition)
                    Console.WriteLine("  {0}", reader.Value)
                Case Xml.XmlNodeType.EndElement
                    Console.Write("{0} {1},{2}  ", reader.Depth, lineInfo.LineNumber, lineInfo.LinePosition)
                    Console.WriteLine("</{0}>", reader.Name)
            End Select
        End While
    Catch ex As Exception
        ErrorMessage = ex.Message
    End Try
End If

' Close the reader.
reader.Close()

If Not String.IsNullOrWhiteSpace(ErrorMessage) Then
    Console.WriteLine()
    Console.WriteLine(ErrorMessage)
End If

Results

0 1,2 <test>
1 2,4 <proper>
1 3,5 </proper>
1 4,4 <wrong>
2 5,4 <wrong>
3 6,4 <right>
3 7,5 </right>

The 'wrong' start tag on line 5 position 4 does not match the end tag of 'test'. Line 8, position 3.

[Radjesh Klauke]

heya kevin. Thanks for the info. The issue here is that i only want to return (when we take your example) "line 5, position 4". The rest is not really interesting for me.

[kareninstructor]

heya kevin. Thanks for the info. The issue here is that i only want to return (when we take your example) "line 5, position 4". The rest is not really interesting for me.

Well I am sure this could be done in Regex but here is a brute force method. Mocked represents our exception message. Yes this can be optimized in string functionality, I did this fast and it works.

Dim Mocked As String = "The 'wrong' start tag on line 5 position 4 does not match the end tag of 'test'. Line 8, position 3."

If Mocked.ToLower.Contains("line") AndAlso Mocked.ToLower.Contains("position") AndAlso Mocked.ToLower.Contains("does") Then
    Dim Index As Integer = Mocked.ToLower.IndexOf("line") + 4
    Dim Temp As String = Mocked.Substring(Index).TrimStart
    Index = Temp.ToLower.IndexOf("position")
    Console.WriteLine("Line index is " & Temp.Substring(0, Index))
    Temp = Temp.Substring(Index)
    Temp = Temp.Replace("position", "").TrimStart
    Index = Temp.ToLower.IndexOf("does")
    Console.WriteLine("Postion is " & Temp.Substring(0, Index))
End If