在Ember中，每当属性更改时，如何在控制器中调用函数

Question

I would like the function exampleFunction to be called every time `exampleProperty' changes. How should I set that up? Seems this has changed recently. I'm using 1.0.0-RC1.

The template:

   <div id="container">
      {{view Ember.TextField valueBinding="exampleProperty"}}
    </div>

The controller:

ExampleApp.ApplicationController = Ember.Controller.extend({

  exampleProperty: "example",

  exampleFunction: function() {
    console.log("exampleProperty was changed");
  }

});

Answer 1

You would define exampleFunction as an observer. The most straightforward syntax is to use the 'observes' method on Function as such:

exampleFunction: function () {
    console.log("property changed");
}.observes('exampleProperty')

You can read more about observers (and more) at the Ember guide: http://emberjs.com/guides/object-model/observers/

Answer 2

You would create a "observes" property.

ExampleApp.ApplicationController = Ember.Controller.extend({

  exampleProperty: "example",

  exampleFunction: function() {
    console.log("exampleProperty was changed");
  }.observes("exampleProperty")

});