Umbraco IHttpModule to switch to an optional [TemplateAlias]Mobile template when mobile devices are detected

gistfile1.cs

using System;
using System.Linq;
using System.Web;
using Kowitz.Core.Module;
using Microsoft.Web.Infrastructure.DynamicModuleHelper;
using ZeroProximity.DeviceDetection;
using umbraco;
using umbraco.cms.businesslogic.template;

[assembly: PreApplicationStartMethod(typeof(MobileRewriteModule), "Start")]
namespace Kowitz.Core.Module
{
    public sealed class MobileRewriteModule : IHttpModule
    {
        readonly IMobileDeviceDetection _deviceDeviceDetection = DeviceDetectionFactory.GetDefaultImplementation();

        void IHttpModule.Dispose() {
        }

        void IHttpModule.Init(HttpApplication application) {

            application.PostResolveRequestCache += delegate(object sender, EventArgs e) {

                if (application.Context.Items.Contains("pageID") == false) return;

                var result = _deviceDeviceDetection.Match(application.Context.Request.UserAgent);
                if (result.IsMobile)
                {
                    var page = umbraco.NodeFactory.Node.GetCurrent();
                    if (application.Context.Request.Url.Query.Contains("?")) return;

                    var template = new template(page.template);

                    var tryGetMobileTemplate = Template.GetAllAsList().FirstOrDefault(x => x.Alias == template.TemplateAlias + "Mobile");
                    if (tryGetMobileTemplate != null)
                    {
                        application.Context.RewritePath(string.Format("{0}?alttemplate={1}", page.Url, tryGetMobileTemplate.Alias));
                    }
                }

            };
        }

        private static bool _startWasCalled;

        public static void Start()
        {
            if (_startWasCalled) return;

            _startWasCalled = true;
            DynamicModuleUtility.RegisterModule(typeof(MobileRewriteModule));
        }
    }
}

@leekelleher do you have a version for 7.1.8?