KnockoutJS订阅具有相同回调操作的多个observable [英] KnockoutJS subscribe to multiple observables with same callback action

问题描述

我在KnockoutJS中有一个模型类，它有多个我想订阅的值。每个订阅都将执行相同的任务，如下所示：

I've got a model class in KnockoutJS which has multiple values that I'd like to subscribe to. Each subscription will perform the same task, like so:

function CaseAssignmentZipCode(zipCode, userId, isNew) {
  var self = this;
  self.zipCode = ko.observable(zipCode);
  self.userId = ko.observable(userId);
  self.isNew = isNew;
  self.isUpdated = false;

  self.zipCode.subscribe(function () { self.isUpdated = true; });
  self.userId.subscribe(function () { self.isUpdated = true; });
}

有没有办法将这两个调用合并到订阅中，这样我就可以使用一个订阅监视两个值？

Is there a way to combine these two calls to subscribe, so that I can use one subscription to 'watch' both values?

推荐答案

您可以为此目的使用计算的observable。您只需要确保在read函数中访问每个observable的值。可能是这样的：

You can use a computed observable for this purpose. You just need to make sure that you access the value of each observable in the read function. Would be something like:

ko.computed(function() {
   self.zipCode();
   self.userId();
   self.isUpdated = true;
});

因此，你会依赖两个observable并设置你的旗帜。

So, you get dependencies on the two observables and set your flag.

此外，如果您正在寻找类似脏标志的东西，那么您可能会考虑以下内容： http://www.knockmeout.net/2011/05/creating-smart-dirty-flag-in-knockoutjs.html 。这个想法是你使用一个在对象上调用ko.toJS（）的计算observable来解包它的所有可观察对象。

Also, if you are looking for something like a "dirty" flag, then you might consider something like: http://www.knockmeout.net/2011/05/creating-smart-dirty-flag-in-knockoutjs.html. The idea is that you use a computed observable that calls ko.toJS() on an object to unwrap all of its observables.

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