Fix/8439 hql sort factory (#8440)

* Additional methods to extend the sort capabilities for projections

* Added some comments

src/Orchard/ContentManagement/DefaultHqlQuery.cs

@@ -251,8 +251,14 @@ namespace Orchard.ContentManagement {
                     sort.Item2(sortFactory);
 
                     if (!sortFactory.Randomize) {
-                        sb.Append(", ");
+                        if (!string.IsNullOrWhiteSpace(sortFactory.PropertyName)) {
-                        sb.Append(sort.Item1.Name).Append(".").Append(sortFactory.PropertyName);
+                            sb.Append(", ");
+                            sb.Append(sort.Item1.Name).Append(".").Append(sortFactory.PropertyName);
+                        }
+                        if (!string.IsNullOrWhiteSpace(sortFactory.AdditionalSelectStatement)) {
+                            sb.Append(", ");
+                            sb.Append(sortFactory.AdditionalSelectStatement);
+                        }
                     }
                     else {
                         // select distinct can't be used with newid()
@@ -325,9 +331,16 @@ namespace Orchard.ContentManagement {
                     }
                 }
                 else {
-                    sb.Append(sort.Item1.Name).Append(".").Append(sortFactory.PropertyName);
+                    if (!string.IsNullOrWhiteSpace(sortFactory.AdditionalOrderByStatement)) {
-                    if (!sortFactory.Ascending) {
+                        sb.Append(sortFactory.AdditionalOrderByStatement);
-                        sb.Append(" desc");
+                        if (!sortFactory.Ascending) {
+                            sb.Append(" desc");
+                        }
+                    } else if (!string.IsNullOrWhiteSpace(sortFactory.PropertyName)) {
+                        sb.Append(sort.Item1.Name).Append(".").Append(sortFactory.PropertyName);
+                        if (!sortFactory.Ascending) {
+                            sb.Append(" desc");
+                        }
                     }
                 }
             }
@@ -454,6 +467,8 @@ namespace Orchard.ContentManagement {
         public bool Ascending { get; set; }
         public string PropertyName { get; set; }
         public bool Randomize { get; set; }
+        public string AdditionalSelectStatement { get; set; }
+        public string AdditionalOrderByStatement { get; set; }
 
         public void Asc(string propertyName) {
             PropertyName = propertyName;
@@ -468,6 +483,18 @@ namespace Orchard.ContentManagement {
         public void Random() {
             Randomize = true;
         }
+
+        public void Asc(string propertyName, string additionalSelectOps, string additionalOrderOps) {
+            Asc(propertyName);
+            AdditionalSelectStatement = additionalSelectOps;
+            AdditionalOrderByStatement = additionalOrderOps;
+        }
+
+        public void Desc(string propertyName, string additionalSelectOps, string additionalOrderOps) {
+            Desc(propertyName);
+            AdditionalSelectStatement = additionalSelectOps;
+            AdditionalOrderByStatement = additionalOrderOps;
+        }
     }
 
     public class DefaultAliasFactory : IAliasFactory{

src/Orchard/ContentManagement/IHqlQuery.cs

@@ -192,6 +192,32 @@ namespace Orchard.ContentManagement {
         /// Sorts randomly
         /// </summary>
         void Random();
+
+        /// <summary>
+        /// Sort in ascending order, adding custom HQL strings
+        /// to the SELECT and ORDER BY statements
+        /// </summary>
+        /// <param name="propertyName">Name of the property</param>
+        /// <param name="additionalSelectOps">Additional HQL for the SELECT statement</param>
+        /// <param name="additionalOrderOps">Additional HQL for the ORDER BY statement</param>
+        /// <remarks>ORDER BY items must appear in the select list if SELECT DISTINCT is specified.
+        /// If such query is being generated by the implementation (as is the case for DefaultHqlQuery),
+        /// make sure to respect that constraint when generating the addtionalOrderOps and
+        /// additionalSelectOps parameters.</remarks>
+        void Asc(string propertyName, string additionalSelectOps, string additionalOrderOps);
+
+        /// <summary>
+        /// Sort in descending order, adding custom HQL strings
+        /// to the SELECT and ORDER BY statements
+        /// </summary>
+        /// <param name="propertyName">Name of the property</param>
+        /// <param name="additionalSelectOps">Additional HQL for the SELECT statement</param>
+        /// <param name="additionalOrderOps">Additional HQL for the ORDER BY statement</param>
+        /// <remarks>ORDER BY items must appear in the select list if SELECT DISTINCT is specified.
+        /// If such query is being generated by the implementation (as is the case for DefaultHqlQuery),
+        /// make sure to respect that constraint when generating the addtionalOrderOps and
+        /// additionalSelectOps parameters.</remarks>
+        void Desc(string propertyName, string additionalSelectOps, string additionalOrderOps);
     }
 }