MVC areas in Sitecore

AreaController.cs

namespace Examples.Common.Sc.Pipelines
{
    using System;
    using Sitecore.Data;
    using Sitecore.Mvc.Pipelines.Response.GetRenderer;
    using Sitecore.Mvc.Presentation;

    public class AreaController : GetRendererProcessor
    {
        public override void Process(GetRendererArgs args)
        {
            if (args.Result != null)
            {
                return;
            }

            var renderingTemplate = args.RenderingTemplate;
            if (renderingTemplate == null)
            {
                return;
            }

            if (!renderingTemplate.DescendsFromOrEquals(new ID("{2A3E91A0-7987-44B5-AB34-35C2D9DE83B9}")))
            {
                return;
            }

            args.Result = this.GetRenderer(args.Rendering, args);
        }

        protected virtual Renderer GetRenderer(Rendering rendering, GetRendererArgs args)
        {
            var action = rendering.RenderingItem.InnerItem.Fields["controller action"].GetValue(true);
            var controller = rendering.RenderingItem.InnerItem.Fields["controller"].GetValue(true);
            var area = rendering.RenderingItem.InnerItem.Fields["area"].GetValue(true);
            var namespaces = rendering.RenderingItem.InnerItem.Fields["namespaces"].GetValue(true);

            if (string.IsNullOrEmpty(namespaces))
            {
                namespaces = string.Empty;
            }

            return new AreaControllerRenderer
            {
                Action = action, 
                Controller = controller, 
                Area = area, 
                Namespaces = namespaces.Split(new[] { '|' }, StringSplitOptions.RemoveEmptyEntries)
            };
        }
    }
}

AreaControllerRenderer.cs

namespace Examples.Common.Sc.Pipelines
{
    using System;
    using System.IO;
    using Sitecore.Mvc.Presentation;
    using Sitecore.StringExtensions;

    public class AreaControllerRenderer : Renderer
    {
        public override string CacheKey
        {
            get
            {
                return "areacontroller::" + this.Controller + "#" + this.Action + "#" + this.Area;
            }
        }

        public string Action { get; set; }

        public string Area { get; set; }

        public string Controller { get; set; }

        public string[] Namespaces { get; set; }

        public override void Render(TextWriter writer)
        {
            var controllerRunner = new AreaControllerRunner(this.Controller, this.Action, this.Area, this.Namespaces);

            var value = controllerRunner.Execute();
            if (string.IsNullOrEmpty(value))
            {
                return;
            }

            writer.Write(value);
        }

        public override string ToString()
        {
            return "Controller: {0}. Action: {1}. Area {2}".FormatWith(new object[] { this.Controller, this.Action, this.Area });
        }
    }
}

AreaControllerRunner.cs

namespace Examples.Common.Sc.Pipelines
{
    using System.Web.Mvc;

    using Sitecore.Mvc.Controllers;
    using Sitecore.Mvc.Presentation;

    public class AreaControllerRunner : ControllerRunner
    {
        public AreaControllerRunner(string controllerName, string actionName, string area, string[] namespaces)
            : base(controllerName, actionName)
        {
            this.Area = area;
            Namespaces = namespaces;
        }

        public string Area { get; set; }

        public string[] Namespaces { get; set; }

        public override string Execute()
        {
            var requestContext = PageContext.Current.RequestContext;

            if (this.Namespaces != null && this.Namespaces.Length > 0)
            {
                if (!requestContext.RouteData.DataTokens.ContainsKey("Namespaces"))
                {
                    requestContext.RouteData.DataTokens.Add("Namespaces", this.Namespaces);
                }
                else
                {
                    requestContext.RouteData.DataTokens["Namespaces"] = this.Namespaces;
                }
            }

            return base.Execute();
        }

        protected override void ExecuteController(Controller controller)
        {
            var requestContext = PageContext.Current.RequestContext;
            var value = requestContext.RouteData.Values["controller"];
            var value2 = requestContext.RouteData.Values["action"];
            var value3 = requestContext.RouteData.DataTokens["area"];
            try
            {
                requestContext.RouteData.Values["controller"] = this.ActualControllerName;
                requestContext.RouteData.Values["action"] = this.ActionName;
                requestContext.RouteData.DataTokens["area"] = this.Area;
                ((IController)controller).Execute(PageContext.Current.RequestContext);
            }
            finally
            {
                requestContext.RouteData.Values["controller"] = value;
                requestContext.RouteData.Values["action"] = value2;
                requestContext.RouteData.DataTokens["area"] = value3;
            }
        }
    }
}

Config.xml

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>

      <mvc.getRenderer>
        <processor patch:before="processor[@type='Sitecore.Mvc.Pipelines.Response.GetRenderer.GetViewRenderer, Sitecore.Mvc']"
                   type="Examples.Common.Sc.Pipelines.AreaController, Examples.Common.Sc" />
      </mvc.getRenderer>
      
  </sitecore>
</configuration>