SharePoint Solutions Blog

At some point in your career as a SharePoint developer you may find it necessary to push out a change to a SharePoint web application"s web.config file for all servers in the farm. In the simplest of scenarios, it may be realistic to make the change to web.config manually, but if you are creating a packaged application for redistribution or there are many servers in the SharePoint farm, a better approach might be to make the web.config modifications programmatically. The WSS v3 API contains the SPWebConfigModification object which allows you to do just that.

For example, if you have been following Daniel Larson"s excellent series of articles on implementing AJAX in WSS v3, you know that AJAX requires an additional HttpHandler be added to a SharePoint web application"s web.config in order to function properly. Here"s the HttpHandler in question:

<add verb="GET" path="ScriptResource.axd" 
  type="Microsoft.Web.Handlers.ScriptResourceHandler, Microsoft.Web.Extensions, 
  Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" 
  validate="false"/>

To push out the AJAX HttpHandler declaration programmatically, the following example console application calls SPWebConfigModification. For the purposes of illustration, I"ve hard coded the web application"s name ("Default Web Site"), but this could have just as easily been passed in as a command line argument:

12/28/2006 - MODIFICATION: Updated code listing with bug fix and added logic to remove the web.config modifcation.

using System;
using System.Globalization;
using Microsoft.SharePoint.Administration;

public class Program
{
    static void Main(string[] args)
    {
        string webAppName = "Default Web Site";

        // Add
        AddAjaxHandlerToWebConfig(webAppName);

        // Remove
        //RemoveAjaxHandlerFromWebConfig(webAppName);
    }

    /// <summary>
    /// Adds the Ajax HttpHandler to a web application"s web.config for all servers in the farm
    /// </summary>
    /// <param name="webAppName"></param>
    private static void AddAjaxHandlerToWebConfig(string webAppName)
    {
        AddOrRemoveAjaxHandlerToWebConfig(webAppName, false);
    }

    /// <summary>
    /// Removes the Ajax HttpHandler from a web application"s web.config for all servers in the farm
    /// </summary>
    /// <param name="webAppName"></param>
    private static void RemoveAjaxHandlerFromWebConfig(string webAppName)
    {
        AddOrRemoveAjaxHandlerToWebConfig(webAppName, true);
    }

    /// <summary>
    /// Adds or removes the Ajax HttpHandler to a web application"s web.config for all servers in the farm
    /// </summary>
    /// <param name="webAppName">Name of web application</param>
    private static void AddOrRemoveAjaxHandlerToWebConfig(string webAppName, bool removeModification)
    {
        string assmDetails =
            string.Format(CultureInfo.InvariantCulture,
            "Microsoft.Web.Handlers.ScriptResourceHandler, Microsoft.Web.Extensions, Version={0}, Culture=neutral,
PublicKeyToken={1}",
            new object[] { "1.0.61025.0", "31bf3856ad364e35" });
       
        SPWebConfigModification modification =
            new SPWebConfigModification("add[@path="ScriptResource.axd"]", "configuration/system.web/httpHandlers");
        modification.Owner = "Ajax";
        modification.Sequence = 0;
        modification.Type = SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode;
        modification.Value =
             string.Format(CultureInfo.InvariantCulture,
             "<add verb=\"{0}\" path=\"{1}\" type=\"{2}\" validate=\"{3}\"/>",
             new object[] { "GET", "ScriptResource.axd", assmDetails, "false" });

        SPWebApplication webApp = SPWebService.ContentService.WebApplications[webAppName];
       
        if (webApp != null)
        {
            if(removeModification)
                webApp.WebConfigModifications.Remove(modification);
            else
                webApp.WebConfigModifications.Add(modification);
           
            SPFarm.Local.Services.GetValue<SPWebService>().ApplyWebConfigModifications();
        }
    }
}

Real world use cases where this functionality may prove useful include calling SPWebConfigModification from a Window"s Installer package Custom Action or perhaps extending stsadm with a custom operation.

In the past I have been using Alcohol 120% or Daemon Tools to mount MSDN ISO images, but I was unable to get either of these tried-and-true utilities to work on the new Vista RTM.

The good news is I was able to get a program called CloneDrive working with no problems at all.

Nice sheep logo. I assume the sheep is an allusion to the genetic cloning thing. In any case, nice work to Elaborate Bytes AG, Cham, Switzerland for this free utility that actually works.

Virtual Sheep? Baahaaah.

Categories: sheep

Today I was doing some research on the OBA RAP for SCM when I stumbled across ArcStream and Skyscapr. 

Sound Greek?  Well, the OBA Reference Application Pack for Supply Chain Management is a reference implementation put together by Microsoft to illustrate how we can build Microsoft Office System 2007 based composite solutions.  Microsoft calls these composite solutions Office Business Applications (OBAs) and describes an OBA as being "designed to support cross-functional processes and allow information workers to collaborate" across organizational boundaries.

ArcStream is a relatively new initiative from the East Region Microsoft Developer & Platform Evangelism Team which strives to provide "a constant flow of technical information as well as networking opportunities for enterprise, application, systems and aspiring architects living and working on the east coast".  A few of the key folks involved with ArcStream include Chad Brooks, Bob Familiar, Chris Bowen and Scott Jamison.

Finally, Skyscapr.net is maintained by the Architecture Strategy Team at Microsoft with the primary goal of "promoting a community-wide discussion about system architecture".  The  site provides access to videos, training, glossaries, ARCasts, and blogs that will help you learn more about technology architecture.

Good stuff! Now if I can just get all the way through Beyond Bullet Points.  So much to read, so little time!