- // 下拉框绑定到$root.availableMeals数组,下拉框显示的文字内容由optionsText: 'mealName'决定,下拉框的值绑定到seats数组中对象SeatReservation的meal属性!
- <select data-bind="options: $root.availableMeals, value: meal, optionsText: 'mealName'"></select>
viewmodel(控制器)
- // Class to represent a row in the seat reservations grid
- function SeatReservation(name, initialMeal) {
- var self = this;
- self.name = name;
- self.meal = ko.observable(initialMeal);
- self.formattedPrice = ko.computed(function() {
- var price = self.meal().price;
- return price ? "$" + price.toFixed(2) : "None";
- });
- }
- // Overall viewmodel for this screen, along with initial state
- function ReservationsViewModel() {
- var self = this;
- // Non-editable catalog data - would come from the server
- self.availableMeals = [
- { mealName: "Standard (sandwich)", price: 0 },
- { mealName: "Premium (lobster)", price: 34.95 },
- { mealName: "Ultimate (whole zebra)", price: 290 }
- ];
- // Editable data
- self.seats = ko.observableArray([
- new SeatReservation("Steve", self.availableMeals[0]),
- new SeatReservation("Bert", self.availableMeals[0])
- ]);
- // Operations
- self.addSeat = function() {
- self.seats.push(new SeatReservation("", self.availableMeals[0]));
- }
- self.removeSeat = function(seat) { self.seats.remove(seat) }
- self.totalSurcharge = ko.computed(function() {
- var total = 0;
- for (var i = 0; i < self.seats().length; i++)
- total += self.seats()[i].meal().price;
- return total;
- });
- }
- ko.applyBindings(new ReservationsViewModel());
view视图
- <h2>Your seat reservations</h2>
- <table>
- <thead><tr>
- <th>Passenger name</th><th>Meal</th><th>Surcharge</th><th></th>
- </tr></thead>
- <!-- Todo: Generate table body -->
- <tbody data-bind="foreach: seats">
- <tr>
- <td><input data-bind="value: name" /></td>
- <td><select data-bind="options: $root.availableMeals, value: meal, optionsText: 'mealName'"></select></td>
- <td data-bind="text: meal().price"></td>
- <td data-bind="text: formattedPrice"></td>
- <td><a href="#" data-bind="click: $root.removeSeat">Remove</a></td>
- </tr>
- </tbody>
- </table>
- <h3 data-bind="visible: totalSurcharge() > 0">
- Total surcharge: $<span data-bind="text: totalSurcharge().toFixed(2)"></span>
- </h3>
- <h2>Your seat reservations (<span data-bind="text: seats().length"></span>)</h2>
- <button data-bind="click: addSeat, enable: seats().length < 5">Reserve another seat</button>