Orchard/src/Orchard.Web/Modules/Orchard.DesignerTools/Controllers/AlternateController.cs

using System.IO;
using System.Web.Mvc;
using Orchard.FileSystems.WebSite;
using Orchard.Localization;
using Orchard.Security;
using Orchard.Mvc.Extensions;
using Orchard.Themes;

namespace Orchard.DesignerTools.Controllers
{
    [Themed]
    public class AlternateController : Controller {
        private readonly IWebSiteFolder _webSiteFolder;
        private readonly IThemeManager _themeManager;

        public AlternateController(IOrchardServices orchardServices, IWebSiteFolder webSiteFolder, IThemeManager themeManager) {
            _webSiteFolder = webSiteFolder;
            _themeManager = themeManager;
            Services = orchardServices;
        }

        public IOrchardServices Services { get; set; }
        public Localizer T { get; set; }

        public ActionResult Create(string template, string alternate, string returnUrl) {
            if (!Request.IsLocal && !Services.Authorizer.Authorize(StandardPermissions.SiteOwner, T("Not authorized to create templates")))
                return new HttpUnauthorizedResult();

            alternate = alternate.Replace("__", "-").Replace("_", ".");

            var currentTheme = _themeManager.GetRequestTheme(Request.RequestContext);
            var alternateFilename = Server.MapPath(Path.Combine(currentTheme.Location, currentTheme.Id, "Views", alternate));

            // use same extension as template, or ".cshtml" if it's a code template))
            if (_webSiteFolder.FileExists(template)) {
                alternateFilename += Path.GetExtension(template);

                using (var stream = System.IO.File.Create(alternateFilename)) {
                    _webSiteFolder.CopyFileTo(template, stream);
                }
            }
            else {
                alternateFilename += ".cshtml";
                using (System.IO.File.Create(alternateFilename)) {}
            }

            return this.RedirectLocal(returnUrl);
        }
    }
}