porting 7.6-rc1 into 8

src/Umbraco.Web/HttpUrlHelperExtensions.cs

@@ -122,5 +122,29 @@ namespace Umbraco.Web
                 }
             }
         }
+
+        /// <summary>
+        /// Return the Base Url (not including the action) for a Web Api service
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="url"></param>
+        /// <param name="actionName"></param>
+        /// <returns></returns>
+        public static string GetUmbracoApiServiceBaseUrl<T>(this UrlHelper url, string actionName)
+            where T : UmbracoApiController
+        {
+            return url.GetUmbracoApiService<T>(actionName).TrimEnd(actionName);
+        }
+
+        public static string GetUmbracoApiServiceBaseUrl<T>(this UrlHelper url, Expression<Func<T, object>> methodSelector)
+            where T : UmbracoApiController
+        {
+            var method = ExpressionHelper.GetMethodInfo(methodSelector);
+            if (method == null)
+            {
+                throw new MissingMethodException("Could not find the method " + methodSelector + " on type " + typeof(T) + " or the result ");
+            }
+            return url.GetUmbracoApiService<T>(method.Name).TrimEnd(method.Name);
+        }
     }
 }