Feature load improvement (#374)

* use lambda expression  => improve database call

* use lambda instead  for each replace call to repository to reduce call to database

* improve readability and maintainability, and add order by

* clean semicolon

* fix use correct catalog item id

src/ApplicationCore/Services/OrderService.cs

@@ -1,11 +1,11 @@
-using Microsoft.eShopWeb.ApplicationCore.Interfaces;
-using Microsoft.eShopWeb.ApplicationCore.Entities.OrderAggregate;
-using System.Threading.Tasks;
+using Ardalis.GuardClauses;
 using Microsoft.eShopWeb.ApplicationCore.Entities;
-using System.Collections.Generic;
-using Ardalis.GuardClauses;
 using Microsoft.eShopWeb.ApplicationCore.Entities.BasketAggregate;
+using Microsoft.eShopWeb.ApplicationCore.Entities.OrderAggregate;
+using Microsoft.eShopWeb.ApplicationCore.Interfaces;
 using Microsoft.eShopWeb.ApplicationCore.Specifications;
+using System.Linq;
+using System.Threading.Tasks;
 
 namespace Microsoft.eShopWeb.ApplicationCore.Services
 {
@@ -33,14 +33,18 @@ namespace Microsoft.eShopWeb.ApplicationCore.Services
             var basket = await _basketRepository.FirstOrDefaultAsync(basketSpec);
 
             Guard.Against.NullBasket(basketId, basket);
-            var items = new List<OrderItem>();
-            foreach (var item in basket.Items)
+
+            var catalogItemsSpecification = new CatalogItemsSpecification(basket.Items.Select(item => item.CatalogItemId).ToArray());
+            var catalogItems = await _itemRepository.ListAsync(catalogItemsSpecification);
+
+            var items = basket.Items.Select(basketItem =>
             {
-                var catalogItem = await _itemRepository.GetByIdAsync(item.CatalogItemId);
-                var itemOrdered = new CatalogItemOrdered(catalogItem.Id, catalogItem.Name,_uriComposer.ComposePicUri(catalogItem.PictureUri));
-                var orderItem = new OrderItem(itemOrdered, item.UnitPrice, item.Quantity);
-                items.Add(orderItem);
-            }
+                var catalogItem = catalogItems.First(c => c.Id == basketItem.CatalogItemId);
+                var itemOrdered = new CatalogItemOrdered(catalogItem.Id, catalogItem.Name, _uriComposer.ComposePicUri(catalogItem.PictureUri));
+                var orderItem = new OrderItem(itemOrdered, basketItem.UnitPrice, basketItem.Quantity);
+                return orderItem;
+            }).ToList();
+
             var order = new Order(basket.BuyerId, shippingAddress, items);
 
             await _orderRepository.AddAsync(order);

src/ApplicationCore/Specifications/CatalogItemsSpecification.cs

@@ -0,0 +1,14 @@
+using Microsoft.eShopWeb.ApplicationCore.Entities;
+using System;
+using System.Linq;
+
+namespace Microsoft.eShopWeb.ApplicationCore.Specifications
+{
+    public class CatalogItemsSpecification : BaseSpecification<CatalogItem>
+    {
+        public CatalogItemsSpecification(params int[] ids) : base(c => ids.Contains(c.Id))
+        {
+
+        }
+    }
+}

src/Web/Services/BasketViewModelService.cs

@@ -5,6 +5,7 @@ using Microsoft.eShopWeb.ApplicationCore.Specifications;
 using Microsoft.eShopWeb.Web.Interfaces;
 using Microsoft.eShopWeb.Web.Pages.Basket;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 
 namespace Microsoft.eShopWeb.Web.Services
@@ -38,10 +39,13 @@ namespace Microsoft.eShopWeb.Web.Services
 
         private async Task<BasketViewModel> CreateViewModelFromBasket(Basket basket)
         {
-            var viewModel = new BasketViewModel();
-            viewModel.Id = basket.Id;
-            viewModel.BuyerId = basket.BuyerId;
-            viewModel.Items = await GetBasketItems(basket.Items); ;
+            var viewModel = new BasketViewModel
+            {
+                Id = basket.Id,
+                BuyerId = basket.BuyerId,
+                Items = await GetBasketItems(basket.Items)
+            };
+            
             return viewModel;
         }
 
@@ -54,27 +58,29 @@ namespace Microsoft.eShopWeb.Web.Services
             {
                 BuyerId = basket.BuyerId,
                 Id = basket.Id,
-                Items = new List<BasketItemViewModel>()
             };
         }
 
         private async Task<List<BasketItemViewModel>> GetBasketItems(IReadOnlyCollection<BasketItem> basketItems)
         {
-            var items = new List<BasketItemViewModel>();
-            foreach (var item in basketItems)
+            var catalogItemsSpecification = new CatalogItemsSpecification(basketItems.Select(b => b.CatalogItemId).ToArray());
+            var catalogItems = await _itemRepository.ListAsync(catalogItemsSpecification);
+
+            var items = basketItems.Select(basketItem =>
             {
-                var itemModel = new BasketItemViewModel
+                var catalogItem = catalogItems.First(c => c.Id == basketItem.CatalogItemId);
+
+                var basketItemViewModel = new BasketItemViewModel
                 {
-                    Id = item.Id,
-                    UnitPrice = item.UnitPrice,
-                    Quantity = item.Quantity,
-                    CatalogItemId = item.CatalogItemId
+                    Id = basketItem.Id,
+                    UnitPrice = basketItem.UnitPrice,
+                    Quantity = basketItem.Quantity,
+                    CatalogItemId = basketItem.CatalogItemId,
+                    PictureUrl = _uriComposer.ComposePicUri(catalogItem.PictureUri),
+                    ProductName = catalogItem.Name
                 };
-                var catalogItem = await _itemRepository.GetByIdAsync(item.CatalogItemId);
-                itemModel.PictureUrl = _uriComposer.ComposePicUri(catalogItem.PictureUri);
-                itemModel.ProductName = catalogItem.Name;
-                items.Add(itemModel);
-            }
+                return basketItemViewModel;
+            }).ToList();
 
             return items;
         }

src/Web/Services/CatalogViewModelService.cs

@@ -48,7 +48,7 @@ namespace Microsoft.eShopWeb.Web.Services
             // the implementation below using ForEach and Count. We need a List.
             var itemsOnPage = await _itemRepository.ListAsync(filterPaginatedSpecification);
             var totalItems = await _itemRepository.CountAsync(filterSpecification);
-         
+
             var vm = new CatalogIndexViewModel()
             {
                 CatalogItems = itemsOnPage.Select(i => new CatalogItemViewModel()
@@ -82,14 +82,13 @@ namespace Microsoft.eShopWeb.Web.Services
             _logger.LogInformation("GetBrands called.");
             var brands = await _brandRepository.ListAllAsync();
 
-            var items = new List<SelectListItem>
-            {
-                new SelectListItem() { Value = null, Text = "All", Selected = true }
-            };
-            foreach (CatalogBrand brand in brands)
-            {
-                items.Add(new SelectListItem() { Value = brand.Id.ToString(), Text = brand.Brand });
-            }
+            var items = brands
+                .Select(brand => new SelectListItem() { Value = brand.Id.ToString(), Text = brand.Brand })
+                .OrderBy(b => b.Text)
+                .ToList();
+
+            var allItem = new SelectListItem() { Value = null, Text = "All", Selected = true };
+            items.Insert(0, allItem);
 
             return items;
         }
@@ -98,14 +97,14 @@ namespace Microsoft.eShopWeb.Web.Services
         {
             _logger.LogInformation("GetTypes called.");
             var types = await _typeRepository.ListAllAsync();
-            var items = new List<SelectListItem>
-            {
-                new SelectListItem() { Value = null, Text = "All", Selected = true }
-            };
-            foreach (CatalogType type in types)
-            {
-                items.Add(new SelectListItem() { Value = type.Id.ToString(), Text = type.Type });
-            }
+
+            var items = types
+                .Select(type => new SelectListItem() { Value = type.Id.ToString(), Text = type.Type })
+                .OrderBy(t => t.Text)
+                .ToList();
+
+            var allItem = new SelectListItem() { Value = null, Text = "All", Selected = true };
+            items.Insert(0, allItem);
 
             return items;
         }