fix referencing issues ...

fix seeding issues ...
fix SubCategory Refresh and Add Support for handle Category Referesh and Referencing ...

Providers/XBaseCategoryProvider.cs

@@ -73,11 +73,11 @@ namespace xCategoryService.Providers
 
             //
             // Retrieve Last Index ...
-            var maxIndex = (await GetReferencingIndexes(
+            var indexes = await GetReferencingIndexes(
                 providedForId: providedForId,
                 cancellationToken: cancellationToken
-            ))
-            .Max();
+            );
+            var maxIndex = indexes.HasChild() ? indexes.Max() : -1;
             if (forIndex > maxIndex)
             {
                 XException.NotFound.Throw();

Providers/XCategoryServiceSeeder.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace xCategoryService.Providers
+{
+    public class XCategoryServiceSeeder
+    {
+        
+    }
+}

Providers/XSubCategoryProvider.cs

@@ -143,17 +143,21 @@ namespace xCategoryService.Providers
             //
             // Reading Category Resource ...
             XCategoryResourceDto categoryResourceDto = null;
-            var categoryDto = await categoryProvider.GetReference(
-                providedForId: id,
-                cancellationToken: cancellationToken
-            );
-            if (!categoryDto.IsNullOrDefault())
+            try
             {
-                categoryResourceDto = await categoryProvider.GetResource(
-                    id: categoryDto.Id,
+                var categoryDto = await categoryProvider.GetReference(
+                    providedForId: id,
                     cancellationToken: cancellationToken
                 );
+                if (!categoryDto.IsNullOrDefault())
+                {
+                    categoryResourceDto = await categoryProvider.GetResource(
+                        id: categoryDto.Id,
+                        cancellationToken: cancellationToken
+                    );
+                }
             }
+            catch { }
 
             //
             var result = new XSubCategoryResourceDto
@@ -439,7 +443,7 @@ namespace xCategoryService.Providers
 
                     //
                     // Update Category Dto if not ...
-                    if (item.Item.Title.IsNullOrEmpty() || 
+                    if (item.Item.Title.IsNullOrEmpty() ||
                         !item.Item.Title
                         .Equals(
                             titleResource.Resource,
@@ -671,6 +675,17 @@ namespace xCategoryService.Providers
                 isValid = true;
             }
 
+            //
+            // Remove all Referencings ...
+            if (isValid)
+            {
+                await categoryProvider.RemoveReferences(
+                    providedForId: id,
+                    connectionId: connectionId,
+                    cancellationToken: cancellationToken
+                );
+            }
+
             //
             if (isValid)
             {
@@ -1123,6 +1138,42 @@ namespace xCategoryService.Providers
                 }
             }
 
+            //
+            // Handle Category ...
+            if (
+                !isDelete &&
+                (isNew || isExists) &&
+                !resource.Category.IsNullOrDefault())
+            {
+                //
+                // Refresh Category ...
+                var category = await categoryProvider.Refresh(
+                    userInfo: userInfo,
+                    resource: resource.Category,
+                    connectionId: connectionId,
+                    cancellationToken: cancellationToken
+                );
+
+                //
+                // Handle SubCategory Referencings ...
+                var references = await categoryProvider.GetAllReferences(
+                    providedForId: id,
+                    cancellationToken: cancellationToken
+                );
+                var hasReference =
+                    references.HasChild() &&
+                    references.Any(r => r.Id == category.Item.Id);
+                if (!hasReference)
+                {
+                    await categoryProvider.AddReference(
+                        providedForId: id,
+                        model: category.Item,
+                        connectionId: connectionId,
+                        cancellationToken: cancellationToken
+                    );
+                }
+            }
+
             //
             // Validate Action ...
             isValid = id.IsValidIntId();
@@ -1162,6 +1213,7 @@ namespace xCategoryService.Providers
             //
             return result;
         }
+
         /// <summary>
         /// Get All Resources as Async Enumerable ... 
         /// </summary>