Order Entry显示模式
当第一次选择一个Order编辑时，此时页面处于只读模式。要创建Knockout与HTML对象的自动绑定，我们必须创建一个JavaScript View Model对象，与Knockout绑定，这样Knockout可以监听View Model对象属性的变化，并自动更新UI。
// Overall viewmodel for this screen, along with initial state
var viewModel = {
EditFields: ko.observable(false),
ReadOnlyMode: ko.observable(false),
DisplayCreateOrderButton: ko.observable(false),
DisplayEditOrderButton: ko.observable(false),
DisplayUpdateOrderButton: ko.observable(false),
DisplayOrderDetailsButton: ko.observable(false),
DisplayCancelChangesButton: ko.observable(true),
SelectedShipVia: ko.observable($("#OriginalShipVia").val()),
Shippers: ko.observableArray(shippers),
OrderID: ko.observable($("#OrderID").val()),
ShipperName: ko.observable($("#ShipperName").val()),
CustomerID: ko.observable($("#CustomerID").val()),
OriginalShipName: ko.observable($("#OriginalShipName").val()),
OriginalShipAddress: ko.observable($("#OriginalShipAddress").val()),
OriginalShipCity: ko.observable($("#OriginalShipCity").val()),
OriginalShipRegion: ko.observable($("#OriginalShipRegion").val()),
OriginalShipPostalCode: ko.observable($("#OriginalShipPostalCode").val()),
OriginalShipCountry: ko.observable($("#OriginalShipCountry").val()),
OriginalRequiredDate: ko.observable($("#OriginalRequiredDate").val()),
OriginalShipVia: ko.observable($("#OriginalShipVia").val()),
ShipName: ko.observable($("#OriginalShipName").val()),
ShipAddress: ko.observable($("#OriginalShipAddress").val()),
ShipCity: ko.observable($("#OriginalShipCity").val()),
ShipRegion: ko.observable($("#OriginalShipRegion").val()),
ShipPostalCode: ko.observable($("#OriginalShipPostalCode").val()),
ShipCountry: ko.observable($("#OriginalShipCountry").val()),
RequiredDate: ko.observable($("#OriginalRequiredDate").val()),
MessageBox: ko.observable("")
}
ko.applyBindings(viewModel);
var viewModel = {
EditFields: ko.observable(false),
ReadOnlyMode: ko.observable(false),
DisplayCreateOrderButton: ko.observable(false),
DisplayEditOrderButton: ko.observable(false),
DisplayUpdateOrderButton: ko.observable(false),
DisplayOrderDetailsButton: ko.observable(false),
DisplayCancelChangesButton: ko.observable(true),
SelectedShipVia: ko.observable($("#OriginalShipVia").val()),
Shippers: ko.observableArray(shippers),
OrderID: ko.observable($("#OrderID").val()),
ShipperName: ko.observable($("#ShipperName").val()),
CustomerID: ko.observable($("#CustomerID").val()),
OriginalShipName: ko.observable($("#OriginalShipName").val()),
OriginalShipAddress: ko.observable($("#OriginalShipAddress").val()),
OriginalShipCity: ko.observable($("#OriginalShipCity").val()),
OriginalShipRegion: ko.observable($("#OriginalShipRegion").val()),
OriginalShipPostalCode: ko.observable($("#OriginalShipPostalCode").val()),
OriginalShipCountry: ko.observable($("#OriginalShipCountry").val()),
OriginalRequiredDate: ko.observable($("#OriginalRequiredDate").val()),
OriginalShipVia: ko.observable($("#OriginalShipVia").val()),
ShipName: ko.observable($("#OriginalShipName").val()),
ShipAddress: ko.observable($("#OriginalShipAddress").val()),
ShipCity: ko.observable($("#OriginalShipCity").val()),
ShipRegion: ko.observable($("#OriginalShipRegion").val()),
ShipPostalCode: ko.observable($("#OriginalShipPostalCode").val()),
ShipCountry: ko.observable($("#OriginalShipCountry").val()),
RequiredDate: ko.observable($("#OriginalRequiredDate").val()),
MessageBox: ko.observable("")
}
ko.applyBindings(viewModel);
我们创建一个Edit Order点击事件函数，当用户点击Edit Order按钮，页面处于编辑模式。代码如下：
$("#btnEditOrder").click(function () {
viewModel.DisplayEditOrderButton(false);
viewModel.DisplayUpdateOrderButton(true);
viewModel.DisplayOrderDetailsButton(false);
viewModel.DisplayCancelChangesButton(true);
viewModel.EditFields(true);
viewModel.ReadOnlyMode(false);
});
viewModel.DisplayEditOrderButton(false);
viewModel.DisplayUpdateOrderButton(true);
viewModel.DisplayOrderDetailsButton(false);
viewModel.DisplayCancelChangesButton(true);
viewModel.EditFields(true);
viewModel.ReadOnlyMode(false);
});
上例中，我们使用Unobtrusive JavaScript这种方式来触发Edit按钮点击事件，实现两种显示与编辑模式的切换。Knockout会监听View Model，实现自动切换。Unobtrusive JavaScript是一项用于页面内容结构与页面呈现分离的新技术。
用户点击Update Oder 按钮，则调用UpdateOrder 函数。UpdateOrder 函数的功能是抓取View Model的值，并创建一个表示物流信息的JavaScript对象。通过JQuery AJAX调用，该对象将提交给UpdateOrderController函数。
function UpdateOrder() {
var shippingInformation = new ShippingInformation();
shippingInformation.OrderID = viewModel.OrderID();
shippingInformation.CustomerID = viewModel.CustomerID();
shippingInformation.ShipName = viewModel.ShipName();
shippingInformation.ShipAddress = viewModel.ShipAddress();
shippingInformation.ShipCity = viewModel.ShipCity();
shippingInformation.ShipRegion = viewModel.ShipRegion();
shippingInformation.ShipPostalCode = viewModel.ShipPostalCode();
shippingInformation.ShipCountry = viewModel.ShipCountry();
shippingInformation.RequiredDate = viewModel.RequiredDate();
shippingInformation.Shipper = viewModel.SelectedShipVia();
var url = "/Orders/UpdateOrder";
$(':input').removeClass('validation-error');
$.post(url, shippingInformation, function (data, textStatus) {
UpdateOrderComplete(data);
});
}
function UpdateOrderComplete(result) {
if (result.ReturnStatus == true) {
viewModel.MessageBox(result.MessageBoxView);
viewModel.OrderID(result.ViewModel.Order.OrderID);
viewModel.ShipperName(result.ViewModel.Order.ShipperName);
viewModel.DisplayEditOrderButton(true);
viewModel.DisplayUpdateOrderButton(false);
viewModel.DisplayOrderDetailsButton(true);
viewModel.DisplayCancelChangesButton(false);
viewModel.DisplayCreateOrderButton(false);
viewModel.EditFields(false);
viewModel.ReadOnlyMode(true);
viewModel.OriginalShipName(result.ViewModel.Order.ShipName);
viewModel.OriginalShipAddress(result.ViewModel.Order.ShipAddress);
viewModel.OriginalShipCity(result.ViewModel.Order.ShipCity);
viewModel.OriginalShipRegion(result.ViewModel.Order.ShipRegion);
viewModel.OriginalShipPostalCode(result.ViewModel.Order.ShipPostalCode);
viewModel.OriginalShipCountry(result.ViewModel.Order.ShipCountry);
viewModel.OriginalRequiredDate(result.ViewModel.Order.RequiredDateFormatted);
viewModel.OriginalShipVia(viewModel.SelectedShipVia());
}
else
{
viewModel.MessageBox(result.MessageBoxView);
}
for (var val in result.ValidationErrors) {
var element = "#" + val;
$(element).addClass('validation-error');
}
}
var shippingInformation = new ShippingInformation();
shippingInformation.OrderID = viewModel.OrderID();
shippingInformation.CustomerID = viewModel.CustomerID();
shippingInformation.ShipName = viewModel.ShipName();
shippingInformation.ShipAddress = viewModel.ShipAddress();
shippingInformation.ShipCity = viewModel.ShipCity();
shippingInformation.ShipRegion = viewModel.ShipRegion();
shippingInformation.ShipPostalCode = viewModel.ShipPostalCode();
shippingInformation.ShipCountry = viewModel.ShipCountry();
shippingInformation.RequiredDate = viewModel.RequiredDate();
shippingInformation.Shipper = viewModel.SelectedShipVia();
var url = "/Orders/UpdateOrder";
$(':input').removeClass('validation-error');
$.post(url, shippingInformation, function (data, textStatus) {
UpdateOrderComplete(data);
});
}
function UpdateOrderComplete(result) {
if (result.ReturnStatus == true) {
viewModel.MessageBox(result.MessageBoxView);
viewModel.OrderID(result.ViewModel.Order.OrderID);
viewModel.ShipperName(result.ViewModel.Order.ShipperName);
viewModel.DisplayEditOrderButton(true);
viewModel.DisplayUpdateOrderButton(false);
viewModel.DisplayOrderDetailsButton(true);
viewModel.DisplayCancelChangesButton(false);
viewModel.DisplayCreateOrderButton(false);
viewModel.EditFields(false);
viewModel.ReadOnlyMode(true);
viewModel.OriginalShipName(result.ViewModel.Order.ShipName);
viewModel.OriginalShipAddress(result.ViewModel.Order.ShipAddress);
viewModel.OriginalShipCity(result.ViewModel.Order.ShipCity);
viewModel.OriginalShipRegion(result.ViewModel.Order.ShipRegion);
viewModel.OriginalShipPostalCode(result.ViewModel.Order.ShipPostalCode);
viewModel.OriginalShipCountry(result.ViewModel.Order.ShipCountry);
viewModel.OriginalRequiredDate(result.ViewModel.Order.RequiredDateFormatted);
viewModel.OriginalShipVia(viewModel.SelectedShipVia());
}
else
{
viewModel.MessageBox(result.MessageBoxView);
}
for (var val in result.ValidationErrors) {
var element = "#" + val;
$(element).addClass('validation-error');
}
}
