Adding & using custom Config section elements to/from app.config

Hello,

I needed some custom configuration that can be readed at flat file level this taking care of resources, dependencies, etc.. so discarding to save the configuration in a DataBase.

I thought about the app.config and by default we can save som configs only with 2 values per register, one for the key and other for the value but my config requirement was of 1 key and 4 attributes or values.

Web Surfing I found some documentation in how to create a custom config that can be saved at app.config and then read it from code using the existent ConfigurationManager tool, the page: http://msdn.microsoft.com/en-us/library/2a1tyt9s.aspx

After a lot of reading and understanding I created a class  in my Win Services solution

Public Class PathSection
    Inherits ConfigurationSection

End Class

adding the properties or attributes that i want to use.

<ConfigurationProperty("name", _
            DefaultValue:="", _
            IsRequired:=True, _
            IsKey:=False)> _
    Public Property Name() As String
        Get
            Return CStr(Me("name"))
        End Get
        Set(ByVal value As String)
            Me("name") = value
        End Set
    End Property

Name() is like we are going to see the property in the code.
name is how we have to set the attribute in the app.config file.

Adding as many properties as we need.

the class must have other methods to serialize & deserialize:

Protected Overrides Sub DeserializeSection( _
        ByVal reader As System.Xml.XmlReader)
        MyBase.DeserializeSection(reader)
        ' Enter your custom processing code here.
    End Sub 'DeserializeSection
    Protected Overrides Function SerializeSection( _
        ByVal parentElement As ConfigurationElement, _
        ByVal name As String, _
        ByVal saveMode As ConfigurationSaveMode) As String
        Dim s As String = _
            MyBase.SerializeSection(parentElement, _
            name, saveMode)
        ' Enter your custom processing code here.
        Return s
    End Function 'SerializeSection

Other two are for simple or collection type of property(we need the collection one):

    ' Declare an element (not in a collection) of the type
    ' UrlConfigElement. In the configuration
    ' file it corresponds to <simple .... />.
    <ConfigurationProperty("simple")> _
    Public ReadOnly Property Simple() _
        As PathElement
        Get
            Dim url As PathElement = _
                CType(Me("simple"),  _
                PathElement)
            Return url
        End Get
    End Property

    ' Declare a collection element represented
    ' in the configuration file by the sub-section
    ' <urls> <add .../> </urls>
    ' Note: the "IsDefaultCollection = false"
    ' instructs the .NET Framework to build a nested
    ' section like <urls> ...</urls>.
    <ConfigurationProperty("paths", _
        IsDefaultCollection:=False)> _
    Public ReadOnly Property Paths() _
        As PathElementCollection
        Get
            Dim pathElementsCollection _
                As PathElementCollection = _
                CType(Me("paths"), PathElementCollection)
            Return pathElementsCollection
        End Get
    End Property

Ok, we have the tools to do the job, so now, how to use it?

Well, first adding the app.config file using Add-->New File, in Common Items-->General, Selecting Application Configuration File, and the app.config is added, Open it, and we must see something like this:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <system.diagnostics>
        <sources>
            <!-- This section defines the logging configuration for My.Application.Log -->
            <source name="DefaultSource" switchName="DefaultSwitch">
                <listeners>
                    <add name="FileLog"/>
                    <!-- Uncomment the below section to write to the Application Event Log -->
                    <!--<add name="EventLog"/>-->
                </listeners>
            </source>
        </sources>
        <switches>
            <add name="DefaultSwitch" value="Information" />
        </switches>
        <sharedListeners>
            <add name="FileLog"
                 type="Microsoft.VisualBasic.Logging.FileLogTraceListener, Microsoft.VisualBasic, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"
                 initializeData="FileLogWriter"/>
            <!-- Uncomment the below section and replace APPLICATION_NAME with the name of your application to write to the Application Event Log -->
            <!--<add name="EventLog" type="System.Diagnostics.EventLogTraceListener" initializeData="APPLICATION_NAME"/> -->
        </sharedListeners>
    </system.diagnostics>
</configuration>

There's no <configSections> element so we are going to add it, at the begining just after:

<?xml version="1.0" encoding="utf-8"?><configuration>
The <configSections> element is to declare the section that we just created before,so must looks like this:

<?xml version="1.0" encoding="utf-8"?><configuration>
  <configSections>

  </configSections>

 Between <configSections></configSections> we are going to declare our section created before inserting this: <section name="ConfPaths" type="CFD.PathSection, EDIOrganizer" requirePermission="false" />, I will explain each part:

<section name="ConfPaths" //This is the name that we want to name or declare our section.
type="CFD.PathSection, EDIOrganizer" //This type is constructed by 2 parts comma separated, the first one is the Root namespace dot our class name for the section, the second one is the Assembly name. (This info is at the Solution properties).

requirePermission="false" //documented at: http://msdn.microsoft.com/en-us/library/system.configuration.sectioninformation.requirepermission.aspx

Once declared our section we can use it, our section is named section name="ConfPaths" so we add it:

<ConfPaths name="OrganizePaths"></ConfPaths>

Inside declare the collection name that we set at our Section Class <ConfigurationProperty("paths", _
 <ConfPaths name="OrganizePaths">
    <Paths>

    </Paths>
</ConfPaths>
Now our objective declare all the elements with the attributes that we configured in the Section Class.


<ConfPaths name="OrganizePaths">
    <Paths>
        <add name="0" source="E:\Root" xmltarget="E:\XML" pdftarget="E:\PDF" />
        ...
        ...
    </Paths>
</ConfPaths>


To get access to this config section at code we can use:

' Get the current configuration file.
Dim config As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration( _
                ConfigurationUserLevel.None)
' Get the MyUrls section.
Dim SConf As PathSection = config.GetSection("ConfPaths")

At this point we finished adding & using custom config elements.