XPath Analyzer

<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Xml" %>
<%@ Import Namespace="System.Xml.XPath" %>

<script language="VB" runat="server">

Dim intIndent as Integer = 0
Dim xDoc as XPathDocument
Dim xNav as XPathNavigator

Sub btnAnalyze_Click(obj as Object, e as EventArgs)
	Dim xNodeIterator as XPathNodeIterator
	Dim objTable as DataTable
	Dim objRow as DataRow
	Dim strAttribute as String
	Dim intTotalNode as Integer = 0
	Dim strNodeType as String

	Try
		'Instantiate XPathDocument and load XML document
		xDoc = New XPathDocument(Server.MapPath(txtXML.Text))

		'Instantiate XPathNavigator
		xNav = xDoc.CreateNavigator()

		'Create temporary table to keep query result
		objTable = New DataTable("QueryResult")
		objTable.Columns.Add("node", Type.GetType("System.String"))
		objTable.Columns.Add("value", Type.GetType("System.String"))
		objTable.Columns.Add("attribute", Type.GetType("System.String"))

		'Execute XPath query
		xNodeIterator = xNav.Select(txtXPath.Text)

		'Iterate through the resultant node set
		While xNodeIterator.MoveNext()

			'Count the number of nodes in the node set
			intTotalNode += 1

			'Get the current node as XPathNavigator object
			xNav = xNodeIterator.Current

			'Create a new row in the temporary table
			objRow = objTable.NewRow()

			'Fill the first column of new row
			Select Case xNav.NodeType
				Case XPathNodeType.Element
					strNodeType = "&lt;&gt;"
				Case XPathNodeType.Attribute
					strNodeType = "="
				Case XPathNodeType.Text
					strNodeType = "Abc"
				Case XPathNodeType.Comment
					strNodeType = "&lt;!&gt;"
				Case Else
					strNodeType = ""
			End Select
			objRow("node") = "<font color=""red""><b>" & strNodeType & "</b></font> " & xNav.Name

			'Fill the second column of new row
			If xNav.MoveToFirstChild() Then
				objRow("value") = RenderTree()
				xNav.MoveToParent()
			Else
				objRow("value") = xNav.Value
			End If

			'Fill the third column of new row
			strAttribute = ""
			If xNav.NodeType = XPathNodeType.Attribute Then
				objRow("attribute") = "n/a"
			Else
				'Iterate through attributes if any
				If xNav.MoveToFirstAttribute() Then
					Do
						strAttribute += xNav.Name & ": " & xNav.Value & "<br>"
					Loop While xNav.MoveToNextAttribute()
					xNav.MoveToParent()
					objRow("attribute") = strAttribute
				End If
			End If

			'Effectively add the new row to the temporary table
			objTable.Rows.Add(objRow)
		End While

		lblMessage.Text = "Total nodes found: " & intTotalNode.ToString()

		'Bind data grid
		objRepeater.DataSource = objTable.DefaultView
		objRepeater.DataBind()

	Catch ex as Exception
		lblMessage.Text = "<font class=""error"">" & ex.Message & "</font>"
	End Try
End Sub

Function RenderTree() As String
	Dim strRenderTree As String

	'Iterate through all siblings
	Do
		Select Case xNav.NodeType
			Case xPathNodeType.Text
				strRenderTree += xNav.Value
			Case xPathNodeType.Comment
				strRenderTree += "&lt;!-- " & xNav.Value & "--&gt;<br>"
			Case Else
				'Render indent
				strRenderTree += RenderHTMLSpace(intIndent)

				'Render opening tag
				strRenderTree += "&lt;" & xNav.Name

				'Render attributes if any
				If xNav.MoveToFirstAttribute() Then
					Do
						strRenderTree += " " & xNav.Name & "= """ & xNav.Value & """"
					Loop While xNav.MoveToNextAttribute()
					xNav.MoveToParent()
				End If
				strRenderTree += "&gt;"

				'Render child nodes if any
				If xNav.MoveToFirstChild() Then
					If xNav.NodeType <> xPathNodeType.Text Then
						strRenderTree += "<br>"
					End If

					intIndent += 2

					'Invoke this function recursively
					strRenderTree += RenderTree()

					intIndent -= 2

					'Move back to the parent node
					xNav.MoveToParent()
				End If

				'Render closing tag
				strRenderTree += "&lt;/" & xNav.Name & "&gt;" & "<br>"
		End Select
	Loop While (xNav.MoveToNext())
	RenderTree = strRenderTree
End Function

Function RenderHTMLSpace(byVal intTotalSpace as Integer) as String
	Dim intLoop as Integer
	Dim strHTMLSpace as String
	For intLoop = 1 to intTotalSpace
		strHTMLSpace += "&nbsp;"
	Next
	RenderHTMLSpace = strHTMLSpace
End Function

</script>

<html>
<head>
<title>XPath Analyzer</title>
</head>
<style>
body {
  font-size: 10pt;
  font-family: verdana,helvetica,arial,sans-serif;
  color: #000000;
  background-color:#eeeedd;
}

font.title {
  font-size: 14pt;
  font-weight: bold;
  font-family: verdana,helvetica,arial,sans-serif;
  color: #000000;
}

td.heading {
  color: #ffffff;
  font-size: 10pt;
  font-family: verdana,helvetica,arial,sans-serif;
  background-color:#900B08;
}

td.normal {
  color: #000000;
  font-size: 8pt;
  font-family: verdana,helvetica,arial,sans-serif;
  background-color:#ffffff;
}

td.alternating {
  color: #000000;
  font-size: 8pt;
  font-family: verdana,helvetica,arial,sans-serif;
  background-color:#e0e0e0;
}

.textbox {
  font-size: 8pt;
  font-family: verdana,helvetica,arial,sans-serif;
}

.button {
	border: 1px solid #000000;
	background-color: #ffffff;
}

.error {
  font-size: 10pt;
  font-family: verdana,helvetica,arial,sans-serif;
  color: #ff0000;
}
</style>

<body>
<form runat="server">
<table>
  <tr>
    <td colspan="2"><font class="title">XPath Analyzer</font></td>
  </tr>
  <tr>
    <td class="heading">XML Virtual Path:</td>
	<td><asp:textbox class="textbox" id="txtXML" columns="30" runat="server" /></td>
  </tr>
  <tr>
    <td class="heading">XPath String:</td>
	<td><asp:textbox class="textbox" id="txtXPath" columns="75" runat="server" /></td>
  </tr>
  <tr>
    <td colspan="2"><asp:button class="button" id="btnAnalyze" onClick="btnAnalyze_Click" text="Analyze" runat="server" /></td>
  </tr>
</table>
<br>
<asp:label id="lblMessage" EnableViewState="false" runat="server" />
<asp:repeater id="objRepeater" EnableViewState="false" runat="server">
  <HeaderTemplate>
    <table border="1" cellpadding="2" cellspacing="0" width="100%" style="border-collapse: collapse" bordercolor="#000000">
	  <tr>
	    <td class="heading">Node</td>
		<td class="heading">Value/Descendant</td>
		<td class="heading">Attributes</td>
	  </tr>
  </HeaderTemplate>
  <ItemTemplate>
      <tr>
	    <td class="normal" valign="top"><%# Container.DataItem("node") %></td>
		<td class="normal" valign="top"><%# Container.DataItem("value") %></td>
		<td class="normal" valign="top"><%# Container.DataItem("attribute") %></td>
	  </tr>
  </ItemTemplate>
  <AlternatingItemTemplate>
      <tr>
	    <td class="alternating" valign="top"><%# Container.DataItem("node") %></td>
		<td class="alternating" valign="top"><%# Container.DataItem("value") %></td>
		<td class="alternating" valign="top"><%# Container.DataItem("attribute") %></td>
	  </tr>
  </AlternatingItemTemplate>
  <FooterTemplate>
    </table>
  </FooterTemplate>
</asp:repeater>
</form>
</body>
</html>