Extending the SharePoint Security Trimmed Control to support SharePoint Groups

We all know that (SPSecurityTrimmedControl) SharePoint Security Trimmed Control comes to our rescue when we need to show role/permission based data in SharePoint. It helps you Conditionally renders the contents of the control to the current user only if the current user has permissions defined in the PermissionString.

<Sharepoint:SPSecurityTrimmedControl runat=”server” Permissions=”ManageLists”>
      Place your control(s) here
</SharePoint:SPSecurityTrimmedControl>

All this is good and works fine for most of the scenarios, however you may seldom find a need to be able to add a “SharePoint Group” instead of a “PermissionString”

So, let’s tell you how…

The idea is to create your wrapper control to support this feature. Let’s get started

Create a custom Web Control and write down the required logic based on your requirements. This should inherit from SPSecurityTrimmedControl

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.SharePoint.WebControls;
using System.Web.UI;
using System.Web;
using Microsoft.SharePoint;

namespace SPSecurityTrimmedControlExtender
{
    public class SPUserGroupTrimmedControl : SPSecurityTrimmedControl
     {
         private List groups = new List();

         public string GroupsString
         {
             get
             {
                 return string.Join(",", groups.ToArray());
             }
             set
             {
                 groups.AddRange(
                     value.Split(new char[] { ',' },
                    System.StringSplitOptions.RemoveEmptyEntries)
                     );
             }
         }

         protected override void Render(HtmlTextWriter output)
         {
             if (!string.IsNullOrEmpty(GroupsString) && IsMember())
             {
                 base.Render(output);
             }
         }

       private bool IsMember()
       {           
           using (SPWeb web = new SPSite(SPContext.Current.Web.Url).OpenWeb())
           {
               bool isMember = false;
               foreach (string group in groups)
               {
                   isMember = web.IsCurrentUserMemberOfGroup(web.Groups[group].ID);
               }
               return isMember;
           }           
       }   
   }
}

Now, put this assembly in GAC and add a safe control entry in the web.config of you web application.

You are now ready to use this in your web page or master page by registering it.

<%@ Register TagPrefix="MyUserGroupExtender" Assembly="SPSecurityTrimmedControlExtender, Version=1.0.0.0, Culture=neutral, PublicKeyToken=121fae78165ba3d4" %>

    //your control to show to the specified group only

And you are done!!!