javascript - Knockout.js 条件绑定

Question

您如何基于其他属性进行条件绑定？

例子..

变量视图模型 = {
   IsAdded = ko.observable(),
   AdditionalBy = ko.observable()   
}

当我显示它时.. 如果 IsAddedBy 为 null 或 false，我不想显示 AdditionalBy

像这样的东西。。

<input type="text" data-bind="value: if (IsAdded != null && IsAdded) { addedBy }"/>

我知道这是不对的，但类似的事情......

Answer 1

What I would do is this;

var ViewModel = function() {
    this.IsAdded = ko.observable('True');
    this.AddedBy = ko.observable('Test');
    this.AddedByText = ko.computed(function(){
        if ( this.AddedBy() != null && this.IsAdded() ) return this.AddedBy()
        return "";
    }, this);
}

Then your input would be

<input type="text" data-bind="value: AddedByText" />

This way you are keeping the logic contained within your ViewModel and separate from the HTML.

Answer 2

这个问题很旧，但它可能会帮助其他人寻找

<input type="text" data-bind="value: IsAdded ? AddedBy : "" "/>

基本上如果 IsAdded 不为空，则将其设置value为 AdditionalBy，否则什么也不做