Manage Web.config from an XML file by using the configSource attribute in ASP.NET 2.0

Introduction

The configSource attribute was firstly introduced in .NET Framework 2.0 to support external configuration files.

After uploading my website to an online server, I needed to manage the website setting from Web.Config, therefore I saved appSettings, connectionStrings, and all settings that I needed to manage in separate XML files, to ease managing and organizing.

This can be done by using the configSource attribute. The configSource attribute was firstly introduced in .NET Framework 2.0 to support external configuration files. This attribute can be added to any configuration section to specify an external file for that section. Using an external configuration source can be useful in many scenarios. For instance, you could place a section into an external configSource if you need an easy method to swap settings for the section depending on the environment.

Using the code

First create an XML file for each web.Config section like appSettings.xml, ConnectionString.xml …, and set the file in the App_Data folder to protect.

Copy each section from web.config and set in XML file as in the following example (appSettings.xml):

<?xml version="1.0" standalone="yes"?>
<appSettings>
  <add key="EnableErrorPage" value="false" />
  <add key="RequiredLogin" value="false" />
  <add key="PublicationsEmail" value="email@domain.com" />
  <add key="AdminFromEmail" value="email@domain.com " />
  <add key="AdminToEmail" value="email@domain.com " />
  <add key="SupportEmail" value="email@domain.com" />
</appSettings>

In Web.config, change the appSettings tag to:

<appSettings configSource="App_Data\WebConfigXML\appSettings.xml"/>

The configSource attribute must be a relative physical path.

Repeat this for each web.config section (connectionStrings, smtp, …).

Now you can manage the XML file from a secure page by using a Gridview control to edit and update the values.

Conclusion

The web.config file is smaller and hence easier to read, and you don't need a complete web.config file for each environment.