使用jquery更新字段不会更新observable [英] Update field with jquery don't update observable

问题描述

我想向stackoverflow社区问好。

我几天前刚开始使用淘汰赛。

正确知道我正在使用它为我正在使用的CMS制作动态菜单构建器。

以下是代码： http://jsfiddle.net/dnlgmzddr/HcRqn/

<问题是，当我从选择框中选择一个元素时，输入字段会按照我的预期更新，但是observable不会反映更改。因此，添加按钮未启用。

我缺少什么？我该如何解决？

谢谢。

解决方案

如果填充了url字段，则需要触发change事件以使observable得到提升。所以，你可以这样做：

  $（＃url）。val（'/ pages /'+ id）.change （）; 
  

除了Knockout精神更多的另一个选择是在你的选择上使用绑定。在这种情况下，您可能希望使用该值填充observable，然后使用手动订阅将格式化的值默认为输入字段。

  this.itemUrl = ko.observable（）; 
 this.selectedUrl = ko.observable（）; 
 this.selectedUrl.subscribe（function（newValue）{
 if（newValue）{
 this.itemUrl（/ pages /+ newValue）; 
} 
 }， 这个）; 
  

然后，将您的选择绑定到 selectedUrl ：

 < select id =pagedListdata-bind =value：selectedUrl> 
< option value =>< option> 
< option value =test>测试< /选项> 
< / select> 
  

以下是一个示例： http://jsfiddle.net/rniemeyer/HcRqn/21/

您还可以消除额外的可观察性如果您的选项的价值是网址，则需要手动订阅。

I want to say hello to the stackoverflow community.

I've just started using knockout a few days ago.

Right know I'm using it to make a dynamic menu builder for a CMS I'm working on.

Here is the code: http://jsfiddle.net/dnlgmzddr/HcRqn/

The problem is that when I choose an element from the select box, the input field update as I expect, but the observable doesn't reflect the change. Because of that, the add button is not enabled.

What am I missing? How can I fix it?

Thank you.

解决方案

When you populate the url field, you would need to trigger the change event to get the observable to be upated. So, you could do:

$("#url").val('/pages/' + id).change(); 

Another option though that is more in the Knockout spirit is to use a binding on your select. In this case, you would likely want to populate an observable with that value, then use a manual subscription to default the formatted value into the input field.

this.itemUrl = ko.observable();
this.selectedUrl = ko.observable();
this.selectedUrl.subscribe(function(newValue) {
    if (newValue) {
        this.itemUrl("/pages/" + newValue);                
    }
}, this);

Then, bind your select to selectedUrl:

    <select id="pagedList" data-bind="value: selectedUrl">
        <option value=""><option>
        <option value="test">Test</option>
    </select>

Here is a sample: http://jsfiddle.net/rniemeyer/HcRqn/21/

You could also eliminate the extra observable and manual subscription if the "value" of your options was the url.

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