Making SharePoint's web.config changes manageable

Scenario:
Making Web.config is pain in the back ( always ). But every deployment need some sort of AppSettings to be stored in Web.Config.

Solution:
I wrote a small feature to handle this, while discussion the same with Sahil over appSetting manageability.

Code ( Feature Receiver ) :

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Administration;

namespace MyClient
{
    class WebConfigModifierFeature : SPFeatureReceiver
    {
        public override void FeatureInstalled(SPFeatureReceiverProperties properties) { }
        public override void FeatureUninstalling(SPFeatureReceiverProperties properties) { }

            public override void FeatureActivated(SPFeatureReceiverProperties properties)
    {
        SPWebApplication application = (SPWebApplication)properties.Feature.Parent;

            foreach (ModificationEntry entry in this.SectionEntries)
            {
                application.WebConfigModifications.Add(this.CreateModification(entry.Name, entry.XPath, entry.Value, SPWebConfigModification.SPWebConfigModificationType.EnsureSection ));
            }
            foreach (ModificationEntry entry2 in this.ChildNodeEntries)
            {
                application.WebConfigModifications.Add(this.CreateModification(entry2.Name, entry2.XPath, entry2.Value, SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode));
            }
            foreach (ModificationEntry entry3 in this.AttributeEntries)
            {
                application.WebConfigModifications.Add(this.CreateModification(entry3.Name, entry3.XPath, entry3.Value, SPWebConfigModification.SPWebConfigModificationType.EnsureAttribute));
            }
            application.WebService.ApplyWebConfigModifications();
    }

    public override void FeatureDeactivating(SPFeatureReceiverProperties properties)
    {
        SPWebApplication application = (SPWebApplication)properties.Feature.Parent;

            foreach (ModificationEntry entry in this.AttributeEntries)
            {
                application.WebConfigModifications.Remove(this.CreateModification(entry.Name, entry.XPath, entry.Value, SPWebConfigModification.SPWebConfigModificationType.EnsureAttribute  ));
            }
            foreach (ModificationEntry entry2 in this.ChildNodeEntries)
            {
                application.WebConfigModifications.Remove(this.CreateModification(entry2.Name, entry2.XPath, entry2.Value, SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode));
            }
            application.WebService.ApplyWebConfigModifications();
  
    }

        private struct ModificationEntry
        {
            public string Name;
            public string XPath;
            public string Value;
      
            // parameterized contructor
            public ModificationEntry( string Name, string XPath, string Value  )
            {
                // intialize structure instances
                this.Name = Name;
                this.XPath = XPath;
                this.Value = Value;
            }
        }

         private ModificationEntry[] AttributeEntries = new ModificationEntry[] {
            new ModificationEntry("file", @"configuration/appSettings", "appSettings.config")};
private ModificationEntry[] SectionEntries = new ModificationEntry[] {
            new ModificationEntry("appSettings", "configuration", "appSettings")};

        public SPWebConfigModification CreateModification(string Name, string XPath, string Value, SPWebConfigModification.SPWebConfigModificationType Type)
        {
            SPWebConfigModification modification = new SPWebConfigModification(Name, XPath);
            modification.Owner ="MyClient";
            modification.Sequence= 0;
            modification.Type=Type;
            modification.Value= Value;
            return modification;
        }
    }
}

Code ( AppSettings.config ) :

<?xml version="1.0"?>
<appsettings>
<add key="GenericError" value="Error occured : Please contact administrator.">
</appsettings>

Question:
Q : Where will I keep the AppSettings.config ?
A : It shud be next to WebApplication web.config.

Q : Where to put while packaging ?
A : Create a folder with name 80 ( if you are using WSPBuilder ).

Q : I have load balanced farm , will this solutuion gonna work ?
A : 100% , AppSettings is part of the solution and will be automatically replicated on all the front end servers.

Q : Any downside to it ?
A : Big problem , if the same feature is activated more than once on the same web application then one will over-ride the changes of other.


Enjoy :-)