.NET Config File Wrapper

Category:

C#, VB.NET, ASP.NET

Type:

Classes

Difficulty:

Intermediate

Author:

Simone Ferrari

Version Compatibility: Visual Basic.NET

More information:

This class wraps .NET config files, allowing you to read or set values for the application associated with them, add sections to them, read or set attribute value, etc.

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

Declarations:
Imports System.Xml

Code:

Public Class ConfigFile

Dim m_strConfigFile As String
    Dim oDoc As New XmlDocument()

Public Sub New(ByVal ConfigFile As String)
        m_strConfigFile = ConfigFile
        oDoc.Load(m_strConfigFile)
    End Sub

' Adds a configuration section
    Public Sub AddConfigSection(ByVal SectionName As String, ByVal HandlerClass As String)

Dim rootNode As XmlNode = oDoc.GetElementsByTagName("configuration").Item(0)

' create the configSections node if it doesn't exist as config sections
        ' need an entry in this node
        Dim oNode As XmlNode
        oNode = oDoc.DocumentElement("configSections")
        If oNode Is Nothing Then
            oNode = oDoc.CreateElement("configSections")
            If rootNode.ChildNodes.Count > 0 Then
                Dim oFirstChild As XmlNode = rootNode.FirstChild
                rootNode.InsertBefore(oNode, oFirstChild)
            Else
                rootNode.AppendChild(oNode)
            End If
        End If

' add the section to the configSectionsNode
        Dim oSubNode As XmlNode
        oSubNode = oDoc.CreateElement("section")
        With oSubNode.Attributes.Append(oDoc.CreateAttribute("name"))
            .Value = SectionName
        End With
        With oSubNode.Attributes.Append(oDoc.CreateAttribute("type"))
            .Value = HandlerClass
        End With
        oNode.AppendChild(oSubNode)

' now create the actual section, if it's not there
        oNode = oDoc.DocumentElement(SectionName)
        If oNode Is Nothing Then
            oNode = oDoc.CreateElement(SectionName)
            rootNode.AppendChild(oNode)
        End If

oDoc.Save(m_strConfigFile)

End Sub

' Checks whether a configuration section exists
    Public Function ConfigSectionExists(ByVal SectionName As String) As Boolean
        If Not oDoc.DocumentElement(SectionName) Is Nothing Then
            Return True
        End If
    End Function

Public Sub SetConfigAttribute(ByVal SectionName As String, ByVal AttributeName As String, ByVal Value As String, Optional ByVal Create As Boolean = True)
        ' get the section node
        Dim oNode As XmlNode = oDoc.DocumentElement(SectionName)
        Dim oAttr As XmlAttribute
        oAttr = oNode.Attributes.ItemOf(AttributeName)
        If oAttr Is Nothing Then
            oAttr = oDoc.CreateAttribute(AttributeName)
            oNode.Attributes.Append(oAttr)
        End If
        oAttr.Value = Value
        oDoc.Save(m_strConfigFile)
    End Sub

Public Sub SetAppSetting(ByVal SettingName As String, ByVal Value As String)

' get the node that corresponds to the setting 
        Dim oSettingNode As XmlNode = GetAppSettingNode(SettingName)

' encrypt the value if requested and then set it

oSettingNode.Attributes.ItemOf("value").Value = Value

' save changes
        oDoc.Save(m_strConfigFile)

End Sub

Private Function AddAppSetting(ByVal SettingName As String) As XmlNode

' get the appSettings node
        Dim oNode As XmlNode = oDoc.DocumentElement("appSettings")

' create the key attribute 
        Dim oKey As XmlAttribute = oDoc.CreateAttribute("key")
        oKey.Value = SettingName

' create the value attribute
        Dim oValue As XmlAttribute = oDoc.CreateAttribute("value")
        oValue.Value = ""

' create the node for the setting
        Dim oChild As XmlNode = oDoc.CreateElement("add")
        oChild.Attributes.Append(oKey)
        oChild.Attributes.Append(oValue)

' add the node to the appSettings section
        oNode.AppendChild(oChild)
        Return oChild

End Function

Private Function GetAppSettingNode(ByVal SettingName As String, Optional ByVal CreateIfNotFound As Boolean = True) As XmlNode

' get the appSettings node
        Dim oNode As XmlNode = oDoc.Docum...