[英]How can i know change in knockout.js ViewModel just by change in its observable property?
I have a ViewModel in knockout.js for personal information. 我在kickout.js中有一个ViewModel以获取个人信息。 I want javascript to think that whole PersonViewModel is changed if just a single observable property in that model is changed.
我希望javascript认为,如果仅更改该模型中的单个可观察属性,则整个PersonViewModel都会更改。
I also have another ViewModel for address and i want the same for it. 我也有另一个ViewModel的地址,我想要同样的地址。 As an end user of program I want program to tell which view model is changed by change in any of the observable property.
作为程序的最终用户,我希望程序告诉通过更改任何可观察属性来更改哪个视图模型。
I could use "subscribe" but that means i would have to subscribe every observable inside the view model and i don't want to do that. 我可以使用“订阅”,但这意味着我将不得不在视图模型中订阅每个可观察的对象,而我不想这样做。 Figuratively, i want to subscribe the whole ViewModel instead of each observable inside it.
具象地,我想订阅整个ViewModel,而不是订阅其中的每个可观察对象。 What should i do?
我该怎么办?
function PersonViewModel() {
this.firstName = ko.observable("John");
this.lastName = ko.observable("Doe");
this.middleName = ko.observable();
this.userName = ko.observable("Johnny");
this.dateOfBirth = ko.observable("12/12/2012");
this.firstName.subscribe(function () {
alert("fisrtName changed");
});
}
function AddressViewModel() {
this.city = ko.observable("@Model.City");
this.street = ko.observable("@Model.Street");
}
var pvm = new PersonViewModel();
var avm = new AddressViewModel();
var pNode = $("#personal-information").get(0);
var aNode = $("#address-information").get(0);
ko.applyBindings(pvm, pNode);
ko.applyBindings(avm, aNode);
My HTML: 我的HTML:
<div id="personal-information">
<input data-bind="value: firstName" type="text" >
<input data-bind="value: lastName" type="text" >
<input data-bind="value: middleName" type="text" >
<input data-bind="value: username" type="text" >
<input data-bind="value: dateOfBirth" type="text" >
</div>
Any help will be appreciated. 任何帮助将不胜感激。 Thanks.
谢谢。
Knockout includes a ko.toJS
function that "clones your view model's object graph, substituting for each observable the current value of that observable, so you get a plain copy that contains only your data and no Knockout-related artifacts." Knockout包含一个
ko.toJS
函数,该函数“克隆视图模型的对象图,为每个可观察对象替换该可观察对象的当前值,因此您将获得一个纯副本,其中仅包含您的数据,而没有与Knockout相关的工件。” If you call ko.toJS
in a computed, that computed will update whenever any observable in the view model is changed. 如果您在计算
ko.toJS
中调用ko.toJS
,则只要视图模型中的任何可观察对象发生更改,该计算对象都会更新。
var p = ko.computed(function () {
return ko.toJS(pvm);
});
var log = ko.observableArray();
p.subscribe(function (value) {
log.push("Person changed");
});
https://jsfiddle.net/mbest/ubLzwerp/ https://jsfiddle.net/mbest/ubLzwerp/
Also see https://stackoverflow.com/a/7850364/1287183 另请参阅https://stackoverflow.com/a/7850364/1287183
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