Gets virtual page routing working, now just need to document.

src/Umbraco.Web.Common/Controllers/UmbracoPageController.cs

@@ -0,0 +1,104 @@
+using System;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.ViewEngines;
+using Microsoft.Extensions.Logging;
+using Umbraco.Core.Models.PublishedContent;
+using Umbraco.Web.Common.Routing;
+using Umbraco.Web.Routing;
+
+namespace Umbraco.Web.Common.Controllers
+{
+    /// <summary>
+    /// An abstract controller for a front-end Umbraco page
+    /// </summary>
+    public abstract class UmbracoPageController : UmbracoController
+    {
+        private UmbracoRouteValues _umbracoRouteValues;
+        private readonly ICompositeViewEngine _compositeViewEngine;
+        private readonly ILogger<UmbracoPageController> _logger;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="UmbracoPageController"/> class.
+        /// </summary>
+        protected UmbracoPageController(ILoggerFactory loggerFactory, ICompositeViewEngine compositeViewEngine)
+        {
+            _logger = loggerFactory.CreateLogger<UmbracoPageController>();
+            _compositeViewEngine = compositeViewEngine;
+        }
+
+        /// <summary>
+        /// Gets the <see cref="UmbracoRouteValues"/>
+        /// </summary>
+        protected virtual UmbracoRouteValues UmbracoRouteValues
+        {
+            get
+            {
+                if (_umbracoRouteValues != null)
+                {
+                    return _umbracoRouteValues;
+                }
+
+                _umbracoRouteValues = HttpContext.Features.Get<UmbracoRouteValues>();
+
+                if (_umbracoRouteValues == null)
+                {
+                    throw new InvalidOperationException($"No {nameof(UmbracoRouteValues)} feature was found in the HttpContext");
+                }
+
+                return _umbracoRouteValues;
+            }
+        }
+
+        /// <summary>
+        /// Gets the current content item.
+        /// </summary>
+        protected virtual IPublishedContent CurrentPage
+        {
+            get
+            {
+                if (!UmbracoRouteValues.PublishedRequest.HasPublishedContent())
+                {
+                    // This will never be accessed this way since the controller will handle redirects and not founds
+                    // before this can be accessed but we need to be explicit.
+                    throw new InvalidOperationException("There is no published content found in the request");
+                }
+
+                return UmbracoRouteValues.PublishedRequest.PublishedContent;
+            }
+        }
+
+        /// <summary>
+        /// Gets an action result based on the template name found in the route values and a model.
+        /// </summary>
+        /// <typeparam name="T">The type of the model.</typeparam>
+        /// <param name="model">The model.</param>
+        /// <returns>The action result.</returns>
+        /// <exception cref="InvalidOperationException">If the template found in the route values doesn't physically exist and exception is thrown</exception>
+        protected IActionResult CurrentTemplate<T>(T model)
+        {
+            if (EnsurePhsyicalViewExists(UmbracoRouteValues.TemplateName) == false)
+            {
+                throw new InvalidOperationException("No physical template file was found for template " + UmbracoRouteValues.TemplateName);
+            }
+
+            return View(UmbracoRouteValues.TemplateName, model);
+        }
+
+        /// <summary>
+        /// Ensures that a physical view file exists on disk.
+        /// </summary>
+        /// <param name="template">The view name.</param>
+        protected bool EnsurePhsyicalViewExists(string template)
+        {
+            ViewEngineResult result = _compositeViewEngine.FindView(ControllerContext, template, false);
+            if (result.View != null)
+            {
+                return true;
+            }
+
+            _logger.LogWarning("No physical template file was found for template {Template}", template);
+            return false;
+        }
+
+    }
+}