使用ko.mapping.fromJS时，不会触发kn​​ockout subscribe回调

Question

I have a question about knockout ko.mapping.fromJS . I know that ko.mapping.fromJS is nothing but make all properties observable. However, when I change the value of the input field. Even the value is changed as showed, but the subscribe callback never fired. Can anyone help me, please? The code snippet in JSFiddle .

html:

<tbody>
  <!-- ko foreach: notes -->
  <tr>
    <td class="col-xs-12">
      <p data-bind="text: value"></p>
      <input type="text" class="form-control" data-bind="value: value" />
    </td>
  </tr>
  <!-- /ko -->
</tbody>
<p data-bind="text: show"></p>

js:

var notes = [
   {
     "key": "Field1",
     "value": "Progress"
   },
   {
     "key": "Field2",
     "value": "Plan"
   }
];

function NotesModel() {
  var self = this;
  self.notes = ko.mapping.fromJS(notes, {}, self.notes);
  self.show = ko.observable('');
};

var notesModel = new NotesModel();
ko.applyBindings(notesModel);

notesModel.notes.subscribe(function(newValue) {
   notesModel.show(JSON.stringify(newValue));
}.bind(notesModel));

Answer 1

Bindrid is correct. notes is an array and the array hasn't changed so there's no reason your subscription would get triggered. If you push a new value to the notes array then the event triggers. You'll have to subscribe to each value individually or make a computed that reads the values of each element and then subscribe to that computed.