繼上一篇文章DinnerNow中的WCF應用 --- 首頁數據加載,我們大概瞭解了一些關於DinnerNow的基本項目結構,以及其中比較主要的兩個解決方案文件。接下來我會繼續以實際網上選餐流程來說明關於DinnerNow中的ASP.NET Ajax Extensions應用場景及其設計方案。
首先請大家看一下這張圖,它標明瞭在訂餐這一業務流程中"查詢餐館"這一用例 DinnerNow所實際執行的方法順序,因爲下文中的一些主要的js方法調用也是以這張圖中所標明的流程來順序處理的.
當然我們還要再次用VS2008打開上文中所說的兩個解決方案文件:
安裝目錄下\solution\DinnerNow - Web\DinnerNow - Web.sln
\solution\DinnerNow - ServicePortfolio2\DinnerNow - ServicePortfolio2.sln
不過這一回要說的重點內容集中在了DinnerNow - Web.sln下的DinnerNow.WebUX項目中.
請看一下search.aspx頁面的運行效果圖:
上圖中的數據請求在上一篇文章中已說過,就是:
service.FindRestaurant(PARAMETERS.map.PostalCode,
PARAMETERS.map.MenuType,
PARAMETERS.map.RestaurantCategory,
PARAMETERS.map.DeadLine,
onRestaurantSeachSuccess, //當操作請求成功後的回調方法
onRestaurantSeachFailed, null);
上面的回調方法的內容如下:
{
var restaurantContainer = document.getElementById("restaurantList");
restaurantContainer.innerHTML = "";
for (var i=0; i<searchResult.length; i++) //綁定數據並進行顯示
{
var restaurantHtml= "<a href=\"javascript:restaurantSelection_Click('"
+ searchResult[i].RestaurantId + "', '"
+ searchResult[i].LogoImageLocation +"', '"
+ searchResult[i].Name +"');\"><img src=\""
+ searchResult[i].LogoImageLocation + "\" alt=\""
+ searchResult[i].Name + "\" width=\"154\" height=\"90\" class=\"thingreenline\" /></a>";
var restaurantElement=document.createElement("span");
restaurantElement.innerHTML = restaurantHtml;
restaurantContainer.appendChild(restaurantElement);
}
DisplayDiv("SearchResultsDivision");
}
通過這個方法的調用實現了上面圖中的顯示效果,當我們單擊了其中某個餐館的圖標之後.
會顯示下面的頁面:
而單擊事件的執行方法如下:
{
/********** RestaurantSelected ***********/生成餐館的信息,如LOGO,餐館名稱,說明等
document.getElementById("restaurantImage").src = logo;
document.getElementById("restaurantName").innerHTML = name;
document.getElementById("restaurantDescription").innerHTML = "Since 1923, the offering fas, friendly and courteous service. We use only the best ingredients and maintain a skilled staff to answer your questions. We have built our reputation on our commitment to providing quality service, which has earned us many valuable customers.";
document.getElementById("restaurantMenuFeed").href = "service/syndication.svc/rss/restaurants/"+ name;
var restaurant = document.getElementById("restaurantID");
restaurant.innerHTML = identifier;
/********** RestaurantSelected ***********/
var service = new DinnerNow.Services.IMenuSearchService();//加載菜單列表
var menuType = return_MenuType();
var selectedMenuType = document.getElementById("selectedMenuItemCategory");
selectedMenuType.value = menuType;
service.GetMenuItemsForMenu(identifier,menuType,restaurantSelection_onSuccess,restaurantSelection_onFailed,null);//請求並加載菜單列表
service.GetMenuTypes(getMenuTypes_onSuccess, getMenuTypes_onFailed, null);//加載菜單類型(上圖中的屬性頁:Breakfast,Dinner,Lunch)
}
其中的GetMenuItemsForMenu,GetMenuTypes方法最終會去調用MenuSearchService類中的同名方法(MenuSearchService.cs文件在DinnerNow.ServicesDinnerNow - ServicePortfolio2.sln解決方案),所以這裏我們還要再切換到ServicePortfolio2.sln下,找到位於DinnerNow.Services項目下的MenuSearchService.cs文件。其中的GetMenuItemsForMenu方法定義如下:
{
Business.Menu menu = new DinnerNow.Business.Menu();
return menu.GetMenuItemsForMenu(new Guid(restaurantId), menuType);//獲取指定類型的菜單數據
}
代碼段中的menu.GetMenuItemsForMenu方法定義如:
{
var results = from mi in db.MenuItems
join m in db.Menus on mi.MenuId equals m.MenuId
where m.RestaurantId == restaurantId
&& m.MenuType == menuType
select new Business.Data.RestaurantMenuItem()
{
Description = mi.Description,
ImageLocation = mi.ImageLocation,
MenuId = mi.MenuId,
MenuItemId = mi.MenuItemId,
Name = mi.Name,
PreparationTime = mi.PreparationTime,
Price = mi.Price
};
return results.ToList();
}
上面的LINQ查詢相當於下面的SQL腳本:
FROM [dbo].[MenuItem] AS [t0]
INNER JOIN [dbo].[Menu] AS [t1] ON [t0].[MenuId] = [t1].[MenuId]
WHERE ([t1].[RestaurantId] = @p0) AND ([t1].[MenuType] = @p1)
而前面所說的GetMenuTypes方法大家也可以找到它最終要去訪問的LINQ代碼如下:
{
var s = (from m in db.Menus
select new DinnerNow.Business.Data.MenuType()
{
MenuTypeName = m.MenuType.Trim()
}).Distinct();
return s.ToList();
}
這裏因爲代碼很簡單,就不多說了.
通過這個業務流程可以看出DinnerNow基本架構思想:
ajax 請求數據 ---> wcf 服務配置 ---> linq 數據訪問.
這樣架構讓整個軟件的架構,流程及開發層次非常清楚。另外因爲使用了 Ajax Extensions,使得開發和閱讀JS代碼感覺就像是在寫C#代碼,使得軟件的可讀性和可維護性上也有很好提升和擴展空間.另外就是在UE上也使在我們可以在一個頁面上完成挑選餐館,選擇食物並進行訂餐的整個流程(接下來將會依次說明).避免了頻繁提交頁面請求而導致的操作繁鎖和服務器訪問超時問題,以及用戶等待時間過長(體驗差)和其它易於出錯的問題.
下面接着上面的JS代碼中的GetMenuItemsForMenu請求的回調方法restaurantSelection_onSuccess來繼續我們的操作流程:
function restaurantSelection_onSuccess(result)
{
var menuItemContainer = document.getElementById("menuList");
menuItemContainer.innerHTML = "";
/******** MenuItems **********/
for (var i=0; i<result.length; i++)
{
var menuItem = result[i];
var menuItemHtml = "<table width='100%' border='0' align='center' cellpadding='8' cellspacing='0' class='thinblueline'><tr><td width='150' align='center' valign='top'><div class='hoverarea'><div><a href=\""
+ menuItem.ImageLocation + "\" target='_blank'> <img id=\"MenuItemImage\" src=\""
+ menuItem.ImageLocation + "\" alt=\""
+ menuItem.Name +"\"/><img id=\"Img1\" src=\""
+ menuItem.ImageLocation+ "\" alt=\""
+ menuItem.Name+"\" class=\"hoverimage_preview\"/></a></div></div></td><td valign='top'><strong>Item # "
+ i + "</strong><br/><strong>"
+ menuItem.Name+"</strong><br/>"
+ menuItem.Description+"<br/><br/><div align='left'><strong>Estimated Delivery Time: "
+ menuItem.PreparationTime+" minutes</strong></div></td><td width='80' align='right' valign='top'><strong>$"
+ menuItem.Price+"</strong><br/><br/><a class=\"noUnderline\" href=\"javascript:AddItemToShoppingCart('"
+ menuItem.Description + "', '"
+ menuItem.ImageLocation + "', '"
+ menuItem.MenuId + "', '"
+ menuItem.MenuItemId + "', '"
+ menuItem.Name + "', '"
+ menuItem.PreparationTime + "', '"
+ menuItem.Price + "');\"><img src=\"images/selectbutton.gif\" border=\"0\" /></a></td></tr></table>";
var menuItemElement=document.createElement("span");
menuItemElement.innerHTML = menuItemHtml;
menuItemContainer.appendChild(menuItemElement);
}
/******** MenuItems **********/
DisplayDivContent4("shoppingCart");
DisplayDiv("MenuDivision");
}
看到這裏,我們在回到頁面上看一下當我們單擊菜單旁邊的"select"按鈕之後所顯示的頁面內容:
而單擊所執行的JS方法如下(該方法用於將訂餐數據加載到購物車中):
{
var menuItem = new DinnerNow.Business.Data.RestaurantMenuItem();
menuItem.Description = description;
menuItem.ImageLocation = imageLocation;
menuItem.MenuId = menuId;
menuItem.MenuItemId = menuItemId;
menuItem.Name = name;
menuItem.PreparationTime = preparationTime;
menuItem.Price = price;
var restaurant = new DinnerNow.Business.Data.RestaurantHeader();
restaurant.RestaurantId = document.getElementById("restaurantID").innerHTML;
restaurant.Name = document.getElementById("restaurantName").innerHTML;
restaurant.LogoImageLocation = document.getElementById("restaurantImage").src;
DinnerNow.ShoppingCartService.AddItem(menuItem,restaurant,menuSort,addItemToShoppingCart_onSuccess,addItemToShoppingCart_onFailed,null);
}
其中的DinnerNow.ShoppingCartService.AddItem調用會生成如下的ajax請求:
/// <param name="selectedItem" type="DinnerNow.Business.Data.RestaurantMenuItem">DinnerNow.WebUX.MenuSearchService.RestaurantMenuItem</param>
/// <param name="restaurant" type="DinnerNow.Business.Data.RestaurantHeader">DinnerNow.WebUX.MenuSearchService.RestaurantHeader</param>
/// <param name="selectedSortOption" type="Number">System.Int32</param>
/// <param name="succeededCallback" type="Function" optional="true" mayBeNull="true"></param>
/// <param name="failedCallback" type="Function" optional="true" mayBeNull="true"></param>
/// <param name="userContext" optional="true" mayBeNull="true"></param>
return this._invoke(this._get_path(), 'AddItem',false,{selectedItem:selectedItem,restaurant:restaurant,selectedSortOption:selectedSortOption},succeededCallback,failedCallback,userContext); }
而最終ajax請求會成爲對如下方法的調用(DinnerNow.WebUX\Code\ShoppingCartService.cs文件中):
public List<ShoppingCartItem> AddItem(RestaurantMenuItem selectedItem, RestaurantHeader restaurant, int selectedSortOption)
{
ShoppingCartItem shoppingCartItem = new ShoppingCartItem()
{
DeliveryTime = selectedItem.PreparationTime,
MenuItemIdentifier = selectedItem.MenuItemId.ToString(),
MenuItemName = selectedItem.Name,
PreparationTime = selectedItem.PreparationTime,
Price = selectedItem.Price,
Quantity = 1,
RestaurantIdentifier = restaurant.RestaurantId.ToString(),
RestaurantImageLocation = restaurant.LogoImageLocation,
RestaurantName = restaurant.Name,
RestaurantItem = selectedItem,
Restaurant = restaurant
};
shoppingCart.AddItem(shoppingCartItem);
return this.RefreshItems(selectedSortOption);
}
通過這個方法我們可以實現將選定的食物放入購物車,並將購物車中已有商品的類型,價格,數據等信息返回到請求頁面中.並通過下面的JS方法來顯示相應的數據信息.
{
var shoppingCartContainer = document.getElementById("shoppingCartList");
shoppingCartContainer.innerHTML = "";
var restaurantId = "";
var firsth = true;
var html = "";
/******** Shopping Cart Items **********/
for (var i=0; i<result.length; i++)
{
var shoppingCartItem = result[i];
var subtotal = (shoppingCartItem.Price * shoppingCartItem.Quantity);//商品價格*數量
var restaurantItemHtml="";
var endPrevRestaurantItemHtml ="";
if (restaurantId != shoppingCartItem.RestaurantIdentifier && menuSort != 1)
{
if (!firsth)
endPrevRestaurantItemHtml = "</table></td></tr>";
firsth = false;
restaurantId = shoppingCartItem.RestaurantIdentifier;
restaurantItemHtml = "<table width='100%' border='0' align='center' cellpadding='4' cellspacing='4' bgcolor='#5686B4' class='thinblueline'><tr><td align='left' bgcolor='#31465B' class='boldWhite'>"
+ shoppingCartItem.RestaurantName + "</td></tr><tr><td>";
}
var shoppingCartHtml = "<table width='100%' border='0' cellspacing='2' cellpadding='2' bgcolor='#5686B4'><tr><td align='left'><a class='noUnderline' href=\"javascript:DeleteItemFromShoppingCart('"
+ shoppingCartItem.MenuItemIdentifier + "');\"><img src='images/delete.gif' alt='Remove item' width='17' height='16'/></a></td><td align='left' width='60%'>"
+ shoppingCartItem.MenuItemName + "</td><td align='left'><input type='text' id='"
+ shoppingCartItem.MenuItemIdentifier + "_itemViewQuantityBox' size='2' class='checkOutFormsField' onchange=\"updateShoppingCartQuantity('"
+ shoppingCartItem.MenuItemIdentifier + "');\" value ='"
+ shoppingCartItem.Quantity + "'></input></td><td align='left' nowrap='nowrap' class='bodyTextWhite'> $"
+ subtotal + "</td></tr>";
html += endPrevRestaurantItemHtml+restaurantItemHtml+shoppingCartHtml+"</table><br/>";
}
/******** Shopping Cart Items **********/
if (html != "")
html+="</td></tr></table>";
var shoppingCartElement=document.createElement("span");
shoppingCartElement.innerHTML = html;
shoppingCartContainer.appendChild(shoppingCartElement);
//ajax調用計算購物車中的Total,ETA信息
DinnerNow.ShoppingCartService.Totals(getTotals_onSuccess, getTotals_onFailed,null);
}
可以看出,整個選購流程還是有些複雜的,但在操作上卻很流暢,讓人感覺不出什麼繁鎖.這其實都要得益於ajax的適當應用.當然微軟的Ajax Extensions無形中也降低了AJAX代碼的開發門檻:)
在下一篇文章中,我們將會繼續訂餐流程,不過重點將會轉移動到DinnerNow - ServicePortfolio2.sln解決方案下,並且因爲DinnerNow中使用了WWF(Windows Work Flow Foundation), 所以下一篇文章的內容可能會更偏向於WWF。如果大家感興趣的話,敬請留意:)
好了,今天的文章就先到這裏了,如果大家有什麼問題歡迎與我交流.
關鍵字:DinnerNow, Ajax Extensions