考虑以下通过敲除映射插件生成的 ViewModel。
var originalData = {
"QuoteSelectedViewModel": {
"ProductName": "Select",
"CoverQuotesViewModel": [
{
"Code": 1,
"Label": "Première Assistance 24h/24 (GRATUITE)",
"IsMandatory": true,
"IsSelected": true,
"DependsOn": []
},
{
"Code": 2,
"Label": "Assistance PLUS 24h/24",
"IsMandatory": false,
"IsSelected": false,
"DependsOn": []
},
{
"Code": 8,
"Label": "Heurts Animaux / Force de la Nature",
"IsMandatory": false,
"IsSelected": false,
"DependsOn": [
2
]
},
]}
}
var viewModel = ko.mapping.fromJS(originalData);
ko.applyBindings(viewModel);
<div data-bind="with: QuoteSelectedViewModel">
selected quote is : <span data-bind="text: ProductName"></span>
<!-- ko foreach: CoverQuotesViewModel -->
<br/>
<div data-bind: if: IsVisible>
<input type="checkbox" data-bind="checked: IsSelected"></input>
<input type="text" data-bind="value: Label, enable: IsSelected"></input>
</div>
<!-- /ko -->
</div>
现在,我想在 IsVisible 返回 false 时隐藏 div。IsVisible 尚不存在,它应该是 CoverQuotesViewModel 数组的每个元素上的计算 observable 函数。
如何在每个元素上生成这个计算的 observable 函数?
谢谢
[编辑] 我在这里添加了一个 jsfiddle:http: //jsfiddle.net/graphicsxp/fpKWM/
[EDIT2] 实际上淘汰文件很清楚如何做到这一点:
当然,如果您愿意,可以在 create 回调中再次调用 ko.mapping.fromJS。一个典型的用例可能是如果你想用一些额外的计算 observables 来扩充原始 JavaScript 对象:
var myChildModel = function(data) { ko.mapping.fromJS(data, {}, this);
this.nameLength = ko.computed(function() { return this.name().length; }, this); }
[编辑]
以下是 Paul 建议的完整代码:(getQuotesSuccess 是一个 AJAX 成功处理程序)
viewModel.getQuotesSuccess = function (result) {
var myCoverQuotesViewModel = function (data, parent) {
var self = this;
ko.mapping.fromJS(data, {}, this);
self.IsVisible = ko.computed(function () {
var visible = true;
if (self.DependsOn().length > 0) {
$.each(self.DependsOn(), function (index, value) {
var dependency = viewModel.QuoteSelectedViewModel().CoverQuotesViewModel.filterByProperty("Code", value);
if (dependency().length > 0) {
visible = visible & dependency()[0].IsSelected();
} else {
visible = false;
}
});
}
return visible;
}, this);
}
var mapping = {
'CoverQuotesViewModel': {
create: function (options) {
return new myCoverQuotesViewModel(options.data, options.parent);
}
}
}
ko.mapping.fromJS(result, mapping, viewModel);
};