I'm trying to create a class which will register events within the Umbraco 7 backend. I'd like to create a plugin which allows you to hide certain doc type properties depending on the user group of the person logged in. (None of the existing plugins appear to be compatible with Umbraco 7)

I'd like to register an event when the edit content screen is loaded - how can I do this?

I've tried following the example in this page: http://24days.in/umbraco/2013/github-snippets-for-umbraco/ but I just receive an error in the Umbraco log (Error creating type Umbraco.Core.Models.PublishedContent.PublishedPropertyType+CompatConverter System.MissingMethodException: No parameterless constructor defined for this object.)

So far I have:

using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using Umbraco.Core;
using umbraco.presentation.masterpages;
using umbraco.uicontrols;
using Umbraco.Core.Logging;

namespace CustomHandlers
{
    public class StartupHandlers : IApplicationEventHandler
    {

        public void OnApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
        {
            umbracoPage.Load += umbracoPage_Load;
        }

        void umbracoPage_Load(object sender, EventArgs e)
        {
            LogHelper.Info(this.GetType(), "HELLO");
        }

    }
}

Can anyone point me in the right direction?

Cheers, Ian.