Knockout.js将JSON对象映射到Javascript对象

Question

我有一个问题,将从服务器收到的Json对象映射到预定义的Javascript对象,该对象包含绑定中使用的所有必要函数

Javascript代码如下

function Person(FirstName, LastName, Friends) {
    var self = this;
    self.FirstName = ko.observable(FirstName);
    self.LastName = ko.observable(LastName);
    self.FullName = ko.computed(function () {
        return self.FirstName() + ' ' + self.LastName();
    })
    self.Friends = ko.observableArray(Friends);
    self.AddFriend = function () {
        self.Friends.push(new Person('new', 'friend'));
    };
    self.DeleteFriend = function (friend) {
        self.Friends.remove(friend);
    };      
}

var viewModel = new Person();

$(document).ready(function () {
    $.ajax({
        url: 'Home/GetPerson',
        dataType: 'json',
        type: 'GET',
        success: function (jsonResult) {
            viewModel = ko.mapping.fromJS(jsonResult);
            ko.applyBindings(viewModel);
        }
    });
});

HTML:

<p>First name: <input data-bind="value: FirstName" /></p>
<p>Last name: <input data-bind="value: LastName" /></p>
<p>Full name: <span data-bind="text: FullName" /></p>
<p>#Friends: <span data-bind="text: Friends().length" /></p>
@*Allow maximum of 5 friends*@
<p><button data-bind="click: AddFriend, text:'add new friend', enable:Friends().length < 5" /></p>
<br>
@*define how friends should be rendered*@
<table data-bind="foreach: Friends">
    <tr>
        <td>First name: <input data-bind="value: FirstName" /></td>
        <td>Last name: <input data-bind="value: LastName" /></td>
        <td>Full name: <span data-bind="text: FullName" /></td> 
        <td><button data-bind="click: function(){ $parent.DeleteFriend($data) }, text:'delete'"/></td> 
    </tr>
</table>

用于获取初始数据的我的ServerSide MVC代码如下所示:

    public ActionResult GetPerson()
    {
         Person person = new Person{FirstName = "My", LastName="Name",
                        Friends = new List<Person>
                        {
                             new Person{FirstName = "Friend", LastName="Number1"},
                             new Person{FirstName = "Friend", LastName="Number2"}
                        }
        };
        return Json(person, JsonRequestBehavior.AllowGet);
    }

我正在尝试使用映射插件将Json加载到我的Javascript对象中,因此一切都可用于绑定(添加函数和Friend对象上的计算属性).

当我使用映射插件时,它似乎不起作用.使用插件时,绑定期间AddFriend方法不可用.是否可以使用映射插件填充JavaScript Person对象,还是必须手动完成所有操作？

Answer 1

您可以查看将映射选项传递给映射插件,特别是此处所述的create回调.

就像是:

var mapping = {
    create: function(options) {
        var person = options.data,
            friends = ko.utils.arrayMap(person.Friends, function(friend) {
               return new Person(friend.FirstName, friend.LastName);   
            });

        return new Person(person.FirstName, person.LastName, friends);
    }
};

示例:http://jsfiddle.net/rniemeyer/5EWDG/

但是,在这种情况下,你没有从映射插件中获得很多功能,你可以不用自己调用Person构造函数并将Friends数组映射到构造函数中的Person对象,如: http:// jsfiddle达网络/ rniemeyer/mewZD /

HTML中的另一个注释:确保对于包含内容的元素,指定起始和结束标记(span并且button在代码中不是这种方式).如果您没有正确指定它们,KO将会遇到问题.