resolve tagging index issues ...

Providers/XBaseFileProvider.cs

@@ -369,6 +369,40 @@ namespace xFileService.Providers
             return await Task.FromResult(result);
         }
 
+        /// <summary>
+        /// Extract all Referencing Models for Specified Key ...
+        /// </summary>
+        /// <param name="providedForId"></param>
+        /// <returns></returns> 
+        public async Task<IEnumerable<XReference<TKey>>> GetAllReferencings(TKey providedForId)
+        {
+            //
+            // Validate ...
+            var isValid =
+                !providedForId.IsNull();
+            if (!isValid)
+            {
+                XException.InvalidArgs.Throw();
+            }
+
+            //
+            var identifier = GetProvidedID(providedForId);
+
+            //
+            var result = FileProvider.FileRepository
+                .AsQueryable()
+                .Where(te => te.References.Contains(identifier))
+                .Select(te => te.References)
+                .SelectMany(tr => tr.ParseXReferenceList<TKey>())
+                .Where(tr => tr.ProvidedFor == Provider && $"{tr.ReferencedTo}" == $"{providedForId}")
+                .OrderBy(tr => tr.Index)
+                .AsEnumerable()
+                ;
+
+            //
+            return await Task.FromResult(result);
+        }
+
         /// <summary>
         /// Count References ...
         /// </summary>
@@ -766,6 +800,38 @@ namespace xFileService.Providers
             return result;
         }
 
+        private async Task<IEnumerable<int>> GetReferencingIndexes(TKey providedForId)
+        {
+            //
+            // Validate ...
+            var isValid =
+                !providedForId.IsNull();
+            if (!isValid)
+            {
+                XException.InvalidArgs.Throw();
+            }
+
+            //
+            var result = new List<int>();
+            var referencings = await GetAllReferencings(providedForId);
+            isValid = !referencings.IsNull() &&
+                referencings.HasChild();
+            if (!isValid)
+            {
+                return result;
+            }
+
+            //
+            result =
+                referencings
+                    .OrderBy(r => r.Index)
+                    .Select(r => r.Index)
+                    .ToList();
+
+            //
+            return result;
+        }
+
         /// <summary>
         /// Check Specified Dto is Has Reference to Provider ...
         /// </summary>