将参数传递给Knockout.js ViewModel中的函数 [英] Passing parameters to a function in knockoutjs viewmodel

问题描述

我有这样的锚标签

<a href="#" class="btn btn-success order-btn" data-bind="attr:{'data-tiername':$data.tierName, 'data-identifier' : $parent.identifier}, click: $root.setPath.bind($data,$data.tierName, $parent.identifier)">Send values</a>

在视图模型中

var appViewModel = {
    setPath: function (data, tier, identifier) {
        alert(data);
        alert(tier);
        alert(identifier);
    },
...........
...........
}

结果是一些敲除js核心代码显示在警报消息中(可能是observable()，dependentObservable()函数的定义和[Object object]的定义，当它们通过JSON.stringify警报时为空)

The result is some knockoutjs core code being displayed in alert message (possibly definitions of observable(),dependentObservable() functions and [Object object] which is empty when alerted with JSON.stringify)

这为什么起作用?

data-bind="attr:{'data-tiername':$data.tierName, 'data-identifier' : $parent.identifier}

但不是这样:

click: $root.setPath.bind($data,$data.tierName, $parent.identifier)

请注意，tierName是一个observable()，标识符是compute()

note that tierName is an observable(), identifier is computed()

在哪里可以找到有关bind()的更多信息?

Where can I find more about bind() ??

推荐答案

由于tierName和identifier是可观察的，因此需要调用它们以访问其值:

Since tierName and identifier are observables, you need to call them to access to their values:

click: $root.setPath.bind($data, $data.tierName(), $parent.identifier())

此外，bind()中的第一个参数将绑定到setPath中的this，所以我想您需要这样的东西:

Also, first argument in bind() will be bound to this in setPath, so I guess you need something like this:

click: $root.setPath.bind(/*will be bound to this*/ $root, $data, 
                      $data.tierName(), $parent.identifier())

最后，如果$data本身是可观察的(不清楚它是否来自您的代码)，那么您也需要调用它:

Finally, if $data itself is an observable (which is not clear if it is from you code), then you need to call it as well:

click: $root.setPath.bind($root, $data(), $data().tierName(), $parent.identifier())

还请记住， bind 已在ECMAScript 5中引入，因此可能并非在所有浏览器中都存在.所以我可能会改成这样:

Also remember bind has been introduced in ECMAScript 5, so it may not be present in all browsers. So I would probably do something like this instead:

click: function(){$root.setPath($data, $data.tierName(), $parent.identifier());}

此处是有关 bind .

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