購物車Demo,前端使用AngularJS,後端使用ASP.NET Web API(2)--前端，以及先後端Session

時間 2019-11-11

標籤購物車 demo 前端使用 angularjs 後端 asp.net asp web api 以及 session 欄目 AngularJS 简体版

原文原文鏈接

chsakell分享了前端使用AngularJS,後端使用ASP.NET Web API的購物車案例，很是精彩，這裏這裏記錄下對此項目的理解。javascript

文章：
http://chsakell.com/2015/01/31/angularjs-feat-web-api/
http://chsakell.com/2015/03/07/angularjs-feat-web-api-enable-session-state/html

源碼：
https://github.com/chsakell/webapiangularjssecurity前端

本系列共三篇，本篇是第二篇。java

購物車Demo,前端使用AngularJS,後端使用ASP.NET Web API(1)--後端
 購物車Demo,前端使用AngularJS,後端使用ASP.NET Web API(2)--前端，以及先後端Session
購物車Demo,前端使用AngularJS,後端使用ASP.NET Web API(3)--Idetity,OWIN先後端驗證git

HomeController用來展現主頁面，並接受前端傳來的Order的編號。angularjs

public calss HomeCOntroller : Controller
{
    public ActionReuslt Index()
    {
        retun View();
    }
    
    public ActionResult ViewOrder(int id)
    {
        using(var context = new SotreContext())
        {
            //這時候Order的導航屬性Gadgets尚未加載出來呢
            var order = context.Orders.Find(id);
            
            //根據Order編號獲取中間表
            var gadgetOrders = context.GadgetOrders.Where(go => go.OrderID == id);
            
            foreach(GadgetOrder gadgetOrder in gadgetOrders)
            {
                //加載中間表某個記錄中對應的導航屬性
                context.Entry(gadgetOrder).Reference(g => g.Gadget).Load();
                order.Gadgets.Add(gadgetOrder.Gadget);
            }
            return View(order);
        }
    }
}

Home/Index.cshtml視圖。github

<html ng-app="gadgetsStore">
    ...
    <body ng-controller='gadgetStoreCtrl'>
        <div ng-hide="checkoutComplete()">
            <div ng-show="showFilter()">
                <form>
                    <input type="text" ng-model="searchItem">
                </form>
            </div>
            <cart-details></cart-details>
        </div>
        <div ng-show="data.error" ng-cloak>
            {{data.error.status}}
        </div>
        <ng-view />
        
        <script src="../../Scripts/angular.js" type="text/javascript"></script>
        <script src="../../Scripts/angular-route.js" type="text/javascript"></script>
        
        <script src="../../app/mainApp.js"></script>
        <script src="../../app/controllers/gadgetsStore.js" type="text/javascript"></script>
        <script src="../../app/filters/storeFilters.js" type="text/javascript"></script>
        <script src="../../app/controllers/gadgetsControllers.js" type="text/javascript"></script>
        <script src="../../app/components/cartCmp.js" type="text/javascript"></script>
        <script src="../../app/controllers/checkoutController.js" type="text/javascript"></
    </body>
</html>

以上，ng-hide="checkoutComplete()"決定着是否顯示所在div，ng-show="data.error" 決定是否顯示報錯，<ng-view />根據路由顯示不一樣視圖，ng-cloak用來避免在切換視圖時頁面的閃爍，<cart-details></cart-details>是自定義的directive，和angularjs有關的js文件放在頂部，applicaiton相關js文件放在其下面，在mainApp.js文件中坐落着一個頂級module名稱是gadgetStore,而頂級controller被放在了gadgetsStoreCtrl.js這個js文件中了。web

最終的界面以下：後端

main.js 聲明頂級module，以及配置路由。api

angular.module("gadgetsStore", ["storeFilters", "storeCart", "ngRoute"])
    .config(function($routeProvider){
        $routeProvider.when("/gadgets",{templateUrl: "app/views/gadgets.html"});
        $routeProvider.when("/checkout",{templateUrl: "app/views/checkout.html"});
        $routeProvider.when("/submitorder",{templateUrl: "app/views/submitOrder.html"});
        $routeProvider.when("/complete",{templateUrl: "app/views/orderSubmitted.html"});
        $routeProvider.otherwise({templateUrl: "app/views/gadgets.html"});
    });

storeFilters, storeCart是咱們自定義的，這裏注入進來。

有了gadgetsStore這個module，如今就爲這個module添加controller等。

angular.module('gadgetsStore')
    .constant('gadgetsUrl', 'http://localhost:8888/api/gadgets')
    .constant('ordersUrl', 'http://localhost:8888/api/orders')
    .constant('categoreisUrl', 'http://localhost:8888/api/categories')
    .controller('gadgetStore', function($scope, $http, $location, gadgetsUrl, categoresUrl, ordersUrl, cart){//由於gadgetsStore依賴引用了storeCart，因此這裏能夠引用cart
    
        //這裏的data被用在主視圖上，因此data的數據會被其它部分視圖共享
        // $scope.data.gadgets
        // scope.data.erro
        // $scope.data.categories
        // $scope.data.OrderLocation
        // $scope.data.OrderID
        // $scope.data.orderError
        $scope.data = {};
        
        $http.get(gadgetsUrl)
            .success(function(data){
                $scope.data.gadgets = data;
            })
            .error(function(error){
                $scope.data.error = error;
            });
            
        $http.get(categoresUrl)
            .success(function(data){
                $scope.data.categories = data;
            })
            .error(function(error){
                $scope.data.error = error;
            });
            
        $scope.sendOrder = function(shippingDetails){
            var order = angular.copy(shippingDetails);
            order.gadgets = cart.getProducts();
            $http.post(ordersUrl, order)
                .success(function(data, status, headers, config){
                    $scope.data.OrderLocation = headers('Location');
                    $scope.data.OrderID = data.OrderID;
                    cart.getProducts().length = 0;
                })
                .error(function(error){
                    $scope.data.orderError = error;
                }).finally(function(){
                    $location.path("/complete");
                });
        }
        
        $scope.showFilter = function(){
            return $location.path() == '';
        }
        
        $scope.checkoutComplete = function(){
            return $location.path() == '/complete';
        }
    });

以上，爲gadgetsStore這個module定義了常量以及controller。把一些規定的uri定義成某個moudule的常量是很好的習慣。經過$location.path方法能夠獲取或設置當前窗口的uri。

好了，頂級的module和頂級的controller有了，Gadget部分如何顯示呢？

根據路由$routeProvider.when("/gadgets",{templateUrl: "app/views/gadgets.html"})， Gadget的視圖被放在了app/views/gadgets.html中了，來看gadgets.html這個視圖。

<div ng-controller="gadgetsCtrl" ng-hide="data.error">

    <!--左側導航部分-->
    <div>
        <!--這裏的selectCategory方法實際是把controller內部的一個變量selectedCategory設爲null-->
        <a ng-click="selectCategory()">Home</a>
        <a ng-repeat="item in data.categoires | orderBy: 'CategoryID'" ng-click="selectCategory(item.CategoryID)" ng-class="getCategoryClass(item.CategoryID)">{{item.Name}}</a>
    </div>
    
    <!--右側Gadgets部分-->
    <div>
        <div ng-repeat="item in data.gadgets | filter: categoryFilterFn | filter: searchItem | range:selectedPage:pageSize">
            {{item.Name}}
            {{item.Price | currency}}
            <img ng-src="../../images/{{item.Images}}" />
            {{item.Description}}
            
            <a ng-click="addProductToCart(item)">Add To Cart</a>
        </div>
        
        <!--分頁部分-->
        <div>
            <a ng-repeat="page in data.gadgets | filter:categoryFilterFn | filter:searchItem | pageCount:pageSize" ng-click="selectPage($index + 1)" ng-class="getPageClass($index + 1)">
                {{$index + 1}}
            </a>
        </div>
    </div>
</div>

以上，把視圖的來源交給了gadgetsCtrl這個controller, 這個controller也被定義在了gadgetsStore這個module中。

gadgetsCtr.js

angular.module("gadgetsStore")
    .constant("gadgetsActiveClass", 'btn-primary')
    .constant('gadgetsPageCount', 3)
    .controller("gadgetsCtrl", function($scope, $filter, gadgetsActiveClass, gadgetsPageCount, cart){
    
        //存儲Category的主鍵CategoryID
        var selectedCategory = null;
        
        //這裏是傳給range和pageCount過濾器的
        $scope.selectedPage = 1;
        $scope.pageSise = gadgetsPageCount;
        
        //實際就是未selectedPage這個變量賦新值
        $scope.selectPage = function(newPage){
            $scope.selectedPage = newPage;
        }
        
        //這裏把Category的編號CategoryID傳了進來
        $scope.selecteCategory = function(newCategory)
        {
            $selectedCategory = newCategory;
            $scope.selectedPage = 1; 
        }
        
        //這裏的product實際就是Gadget
        //過濾出Gadget的CategoryID和這裏的selectedCateogory一致的那些Gadgets
        $scope.categoryFilterFn = fucntion(product){
            return selectedCategory == null || product.CategoryID == selectedCategory;
        }
        
        //category實際是Category的主鍵CategoryID
        $scope.getCategoryClass = function(category){
            return selectedCategory == category ? gadgetsActiveClass : "";
        }
        
        $scope.getPageClass = function(page){
            return $scope.selectedPage = page ? gadgetsActiveClass : "";
        }
        
        $scope.addProductToCart = function(product){
            cart.addProduct(product.GadgetID, product.Name, product.Price, product.CategoryID);
        }
    });

在顯示Gadget列表的時候，<div ng-repeat="item in data.gadgets | filter: categoryFilterFn | filter: searchItem | range:selectedPage:pageSize">，這裏用到了一個自定的過濾器range，這個過濾器被定義在了storeFilters.js中。

var storeFilters = angular.module('storeFilters',[]);

storeFitlers.filter("range", function($filter){
    return function(data, page, size){
        if(angular.isArray(data) && angular.isNumber(page) && angular.isNumber(size)){
            var start_index = (page - 1)*size;
            if(data.legnth < start_index){
                return [];
            } else {
                return $filter("limitTo")(data.splice(start_index), size);
            }
        } else{
            return data;
        }
    }
});

sortFilters.filter("pageCount", function(){
    return function(data, size){
        if(angular.isArray(data))
        {
            var result = [];
            for(var i = 0; i < Math.ceil(data.length/size); i++){
                result.push(i);
            }
        } else {
            return data;
        }
    }
});

再來看$routeProvider.when("/checkout",{templateUrl: "app/views/checkout.html"});這個路由，checkout.html這個部分視圖以下：

<div ng-controller = "cartDetailsController">
    <div ng-show="cartData.length==0">
        no item in the shopping cart
    </div>
    <div ng-hide="cartData.length == 0">
        {{item.count}}
        {{item.Name}}
        {{item.Price | currency}}
        {{(item.Price * item.count) | currency}}
        <button ng-click="remove(item.GadgetID)"></button>
        {{total() | currency}}
        <a href="#">Continue shopping</a>
        <a href="#/submitorder">Place order now</a>
    </div> 
</div>

對應的界面以下：

cartDetailsController這個controller也被放在了頂級module裏。以下：

angular.module("gadgetsStore")
    .controller("cartDetailsController", function($scope, cart){
        $scope.cartData = cart.getProducts();
        
        $scope.total = function(){
            var total  = 0;
            for(var i = 0; i < $scope.cartData.length;i++)
            {
                total += ($scope.cartData[i].Price * $scope.cartData[i].count);
            }
            return total;
        }
        
        $scope.remove = function(id){
            cart.removeProduct(id);
        }
    });

咱們注意到，咱們已經在多個地方注入cart這個服務，這個自定義的服務能夠以factory的方式來建立，若是要用這個cart服務，它所在的module就要被其它module所引用。下面來建立cart服務：

var storeCart = angular.module('storeCart',[]);

storeCart.factory('cart', function(){
    var cartData = [];
    
    return {
        addProduct: function(id, name, price, category){
        
            //用來標記是否已經向購物車裏加了產品
            var addedToExistingItem = false;
            for(var i=0; i < cartData.length;i++)
            {
                if(cartData[i].GadgetID == id){
                    cartData[i].count++;
                    addedToExistingItem = true;
                    break;
                }
            }
            if(!addedToExistingItem)
            {
                cartData.push({
                    count:1, GadgetID: id, Price: price, Name: name, CategoryID:category
                });
            }
        },
        removeProduct: function(id){
            for(var i = 0; i < cartData.legnth; i++){
                if(cartData[i].GadgetID == id){
                    cartData.splice(i, 1);
                    break;
                }
            }
        },
        getProducts:function(){
            return cartData;
        }
    
    };
});

關於購物車部分，咱們還記得，在主視圖用了<cart-details></cart-details>這個自定義的directive，實際也是在storeCart這個module中定義的。

sortCart.directive("cartDetails", function(cart){
    return {
        restrict: "E",
        templateUrl: "app/components.cartDetails.html",
        controller: function($scope){
            var cartData = cart.getProducts();
            
            $scope.total = function(){
                var total =0;
                for(var i = 0; i < cartData.legnth; i++){
                    total += (cartData[i].Price * cartData[i].count);
                }
                return total;
            }
            
            $scope.itemCount = function(){
                var total = 0;
                for(var i = 0; i < cartData.length; i++){
                    total += cartData[i].count;
                }
                return total;
            }
        }
    };
});

以上，對應的視圖爲：

Your cart: {{itemCount()}} items
{total() | currency}
<a href="#/checkout">Checkout</a>

在顯示購物車明細的時候，給出了提交訂單的連接：

<a href="#/submitorder">Place order now</a>

根據路由$routeProvider.when("/submitorder",{templateUrl: "app/views/submitOrder.html"})，是會加載app/views/submitOrder.html部分視圖，界面以下：

對應的html爲：

<form name="shippingForm" novalidate>
    <input name="companyName" ng-model="data.shipping.CompanyName" required />
    <span ng-show="shippingForm.companyName.$error.required"></span>
    
    <input name="name" ng-model="data.shipping.OwnerName" required />
    <span ng-show="shippingorm.name.$error.required"></span>
    
    ...
    <button ng-disabled="shippingForm.$invalid" ng-click="sendOrder(data.shipping)">Complete Order</button>
</form>

sendOrder被定義在了頂級module中：

$scope.sendOrder = function (shippingDetails) {
            var order = angular.copy(shippingDetails);
            order.gadgets = cart.getProducts();
            $http.post(ordersUrl, order)
            .success(function (data, status, headers, config) {
                $scope.data.OrderLocation = headers('Location');
                $scope.data.OrderID = data.OrderID;
                cart.getProducts().length = 0;
            })
            .error(function (error) {
                $scope.data.orderError = error;
            }).finally(function () {
                $location.path("/complete");
            });
        }

/complete會路由到$routeProvider.when("/complete",{templateUrl: "app/views/orderSubmitted.html"})， app/views/orderSubmitted.html部分視圖以下：

其html部分爲：

<div ng-show="data.orderError">
    {{data.orderError.status}}the order could not be placed, <a href="#/submitorder">click here to try again</a>
</div>
<div ng-hide="data.orderError">
    {{data.OrderID}}
    <a href="#">Back to gadgets</a>
    <a href="{{data.OrderLocation}}">View Order</a>
</div>

■ 實現購物車的Session

如今爲止，還存在的問題是：當刷新頁面的時候，購物車內的產品就會消失，即還麼有Session機制。

與ASP.NET Web API路由相關的HttpControllerRouteHandler, HttpControllerHandler, IRequireSessionState。

首先一個繼承內置的HttpControllerHandler，並實現內置的IRequiresSessionState接口。

public class SessionEnabledControllerHandler : HttpControllerHandler, IRequiresSessionState
{
    public SessionEnabledControllerHandler(RouteData routeData)
        : base(routeData)
    { }
}

而後實現一個內置HttpControllerRouteHandler的繼承類。

public class SessionEnabledHttpControllerRouteHandler : HttpControllerRouteHandler
{
    protected override IHttpHandler GetHttpHandler(RequestContext requestContext)
    {
        return new SessionEnabledControllerHandler(requestContext.RouteData);
    }
}

註釋掉WebApiConfig.cs中的代碼：

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        // Web API configuration and services

        // Web API routes
        config.MapHttpAttributeRoutes();

        // Moved to RouteConfig.cs to enable Session
        /*
        config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );
         */
    }
}

在RouteConfig中配置以下：

public class RouteConfig
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        #region Web API Routes

        // Web API Session Enabled Route Configurations
        routes.MapHttpRoute(
            name: "SessionsRoute",
            routeTemplate: "api/sessions/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        ).RouteHandler = new SessionEnabledHttpControllerRouteHandler(); ;

        // Web API Stateless Route Configurations
        routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );
        #endregion

        #region MVC Routes
        routes.MapRoute(
            name: "Default",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
        );
        #endregion
    }
}

以上，須要引用System.Web.Http。

如今，若是但願ItemsController中使用Session，那就這樣請求：

http://localhost:61691/api/sessions/items

若是不想用Session，那就這樣請求：

http://localhost:61691/api/items

如今，在前端，向購物車添加產品相關代碼爲：

addProduct: function (id, name, price, category) {
    var addedToExistingItem = false;
    for (var i = 0; i < cartData.length; i++) {
        if (cartData[i].GadgetID == id) {
            cartData[i].count++;
            addedToExistingItem = true;
            break;
        }
    }
    if (!addedToExistingItem) {
        cartData.push({
            count: 1, GadgetID: id, Price: price, Name: name, CategoryID: category
        });
    }
}

相似地，建立一個模型：

public class CartItem
{
    public int Count { get; set; }
    public int GadgetID { get; set; }
    public decimal Price { get; set; }
    public string Name { get; set; }
    public int CategoryID { get; set; }
}

對應的控制器爲：

public class TempOrdersController : ApiController
{
    //get api/TempOrders
    public List<CartItem> GetTempOrders()
    {
        List<CartItem> cartItems = null;
        
        if(System.Web.HttpContext.Current.Session["Cart"] != null){
            cartItems = (List<CartItem>)System.Web.HttpContext.Current.Session["Cart"];
        }
        
        return cartItems;
    }
    
    //post api/TempOrders
    [HttpPost]
    public HttpResponseMessage SaveOrder(List<CarItem> cartItems)
    {
        if (!ModelState.IsValid)
        {
            return new HttpResponseMessage(HttpStatusCode.BadRequest);
        }

        System.Web.HttpContext.Current.Session["Cart"] = cartItems;

        return new HttpResponseMessage(HttpStatusCode.OK);
    }
}

再回到前端，首先在gadgetsStore這個頂級module中增長有關緩存API的uri常量。

angular.module('gadgetsStore')
    .constant('gadgetsUrl', 'http://localhost:61691/api/gadgets')
    .constant('ordersUrl', 'http://localhost:61691/api/orders')
    .constant('categoriesUrl', 'http://localhost:61691/api/categories')
    .constant('tempOrdersUrl', 'http://localhost:61691/api/sessions/temporders')
    .controller('gadgetStoreCtrl', function ($scope, $http, $location, gadgetsUrl, categoriesUrl, ordersUrl, tempOrdersUrl, cart) {
// Code omitted

從新定義cart這個服務：

storeCart.factory('cart', function(){
    var cartData = [];
    
    return {
        addProduct: function(id, name, price, category){
            var addedToExistingItem = false;
            for(var i = 0; i < cartData.length; i++){
                if(cartData[i].GadgetID == id){
                    cartData[i].count++;
                    addedToExistingItem = true;
                    break;
                }
            }
            if(!addedToExistingItem){
                cartData.push({
                    count:1, GadgetID: id, Price: price, Name: name, Category: category
                });
            }
        },
        removeProduct: fucntion(id){
            for(var i = 0; i < cartData.length; i++){
                if(cartData[i].GadgetID == id){
                    cartData.splice(i, 1);
                    break;
                }
            }
        },
        getProducts: fucntion(){
            return cartData;
        },
        pushItem: function(item){
            cartData.push({
                count: item.Count, GadgetID:item.GadgetID, Price: Item.Price, Name: item.Name, CategoryID: item.CategoryID
            })
        }
    };
});

爲了在頁面每次刷新的時候保證Session的狀態，在主module中添加以下方法：

//用來把每次更新保存到後端的Session中
$scope.saveOrder = function () {
    var currentProducts = cart.getProducts();

    $http.post(tempOrdersUrl, currentProducts)
        .success(function (data, status, headers, config) {
        }).error(function (error) {
        }).finally(function () {
        });
}

//用來每次刷新向後端Session要數據
$scope.checkSessionGadgets = function(){
    $http.get(tempOrdersUrl)
        .success(function(data){
            if(data){
                for(var i = 0; i < data.length; i++){
                    var item = data[i];
                    cart.pushItem(item);
                }
            }
        })
        .error(function(error){
            console.log('error checking session: ' + error) ;
        });
}

而後checkSessionGadgets這個方法就要被運用到主視圖上去，當頁面每次加載的時候調用它。

<body ng-controller='gadgetStoreCtrl' class="container" ng-init="checkSessionGadgets()">

每次向購車添加的時候須要從新更新後端的Session狀態。

$scope.addProductToCart = function (product) {
    cart.addProduct(product.GadgetID, product.Name, product.Price, product.CategoryID);
    $scope.saveOrder();
}

每次從購物車一處的時候須要從新更新後端的Session狀態。

$scope.remove = function (id) {
    cart.removeProduct(id);
    $scope.saveOrder();
}

在用戶提交訂單的時候，須要一出購物車內的產品，再更新後端的Session狀態。

$scope.sendOrder = function (shippingDetails) {
    var order = angular.copy(shippingDetails);
    order.gadgets = cart.getProducts();
    $http.post(ordersUrl, order)
    .success(function (data, status, headers, config) {
        $scope.data.OrderLocation = headers('Location');
        $scope.data.OrderID = data.OrderID;
        cart.getProducts().length = 0;
        $scope.saveOrder();
    })
    .error(function (error) {
        $scope.data.orderError = error;
    }).finally(function () {
        $location.path("/complete");
    });
}