XML Parser - A Simple approach to XML File reading

• Download source - 65 Kb

Introduction

The XML Parser classes are used to simplify the process of loading and accessing a regular XML file.

Some key features:

• XML Load of the file with just an absolute path.
• Collections of Attributes and Nodes for easy access.
• Methods for finding the node(s) you want by name or by attribute(name/value).

The full documentation is included in the zip file. It's documentation.chm.

Background

Some knowledge of how XML files are built is required if you are the one writing the XML files. If you are just reading someone else's file, just know that a XML file is much like a Windows Explorer Tree, in the aspect that each node can have subnodes and value.

Using the code

The document1.xml file i'm using as an example:

<?xml version="1.0" encoding="utf-8" ?>
<root>
  <parent type="Father">John</parent>
  <parent type="Mother">Mary</parent>
  <child id="FirstSon">
    <name>Joseph</name>r>    </child>
  <child id="SecondSon">
    <name>Christian</name>r>  </child>
</root>

Using the code to load a "document1.xml" file:

 Private Sub Page_Load(ByVal sender As System.Object, 
 ByVal e As System.EventArgs) Handles MyBase.Load
    Dim xmlRoot As New SNANET.XMLParser.XMLRoot(
     Server.MapPath("xmlFile1.xml"))
    If xmlRoot.isLoaded Then
      response.write ("File succesfully loaded.")
  End If
  End Sub

Using the code to access the child node number 0 of the root node:

  Private Sub Page_Load(ByVal sender As System.Object, 
 ByVal e As System.EventArgs) Handles MyBase.Load
    Dim xmlRoot As New SNANET.XMLParser.XMLRoot(
     Server.MapPath("xmlFile1.xml"))
    If xmlRoot.isLoaded Then
      response.write (xmlRoot.children(0).name & "=" 
       & xmlRoot.children(0).value)
  End If
  End Sub

Using the code to access the child node number 0 of the root node and print it's attributes:

  Private Sub Page_Load(ByVal sender As System.Object, 
   ByVal e As System.EventArgs) Handles MyBase.Load
    Dim xmlRoot As New SNANET.XMLParser.XMLRoot(
  Server.MapPath("xmlFile1.xml"))
    If xmlRoot.isLoaded Then
    For Each att as SNANET.XMLParser.XMLAttribute In xmlRoot.Attributes
        Response.Write (att.name & "=" & att.value)
    Next
  End If
  End Sub

Using the code to access the child nodes that has the name "Child":

  Private Sub Page_Load(ByVal sender As System.Object, 
   ByVal e As System.EventArgs) Handles MyBase.Load
    Dim xmlRoot As New SNANET.XMLParser.XMLRoot(
   Server.MapPath("xmlFile1.xml"))
    If xmlRoot.isLoaded Then
    For Each item As SNANET.XMLParser.XMLNode In xmlRoot.GetNodesByName("child")
        Response.Write(item.Name & "=" & item.value)
      Next
  End If
  End Sub

Using the code to access the child nodes that has the attribute "type" and that attribute has the value of "Father":

  Private Sub Page_Load(ByVal sender As System.Object,
    ByVal e As System.EventArgs) Handles MyBase.Load
    Dim xmlRoot As New SNANET.XMLParser.XMLRoot(
   Server.MapPath("xmlFile1.xml"))
    If xmlRoot.isLoaded Then
    For Each item As SNANET.XMLParser.XMLNode 
     In xmlRoot.GetNodesByType("type","father")
        Response.Write(item.Name & "=" & item.value)
      Next
  End If
  End Sub

To-Do List (help is most welcome :))

• Enabling the XML Parser to receive the XML text as a parameter.
• Enabling the XML Parser to save the updated XML structure to disk.

History

• [13-OCT-2004] First version of the XML Parser Classes released