Select element in angular not updating modelValue on second selection

问题

I've got a select element bound to a model in an angular view. When filling out the form with the keyboard, I noticed that if you down arrow to the second option the value, the model still represents the first value. This only happens when using the keyboard to fill out the form.

Set up is pretty simple, using angular 1.4.3:

var app = angular.module('app', []);

app.controller('myController', function() {
  var vm = this;

  vm.options = [{
    Id: 1,
    Value: 'A'
  }, {
    Id: 2,
    Value: 'B'
  }, {
    Id: 3,
    Value: 'C'
  }]
});

<script src="https://code.angularjs.org/1.4.3/angular.js"></script>

<body ng-app="app">
  <div ng-controller="myController as ctrl">
    <p>
      Model is not updated on second down button push. Repro:
      <ol>
        <li>Tab to select element</li>
        <li>Hit down and notice the optionId updated to 1</li>
        <li>Hit down again and notice that the displayed value changes to B, but optionId stays as 1</li>
        <li>Hit down again and notice that the displayed value changes to C, and optionId changes to 3</li>
        <li>Hit up and notice that displayed value changes to B, and optionId changes to 2</li>
      </ol>
      Why doesn't the optionId = 2 on the initial selection of B
    </p>
    <select id="mySelect" ng-options="item.Id as item.Value for item in ctrl.options" ng-model="ctrl.optionId" style="width:200px">
    </select>
    <div><strong>optionId: {{ctrl.optionId}}</strong>
    </div>
  </div>
</body>

Why doesn't the model update on the second down arrow press?

Update Here's a plunker that exhibits the behavior, http://plnkr.co/edit/Hiu67NTR3Gpk9jByZtQD?p=info

2nd Update Here's a modified plunker that implements the workaround Matt proposed. This workaround causes the desired behavior in Chrome, Firefox, and Internet Explorer

回答1:

I believe your problem clones a pre-existing angular issue which has a work around available.

Feel free to browse the issue and trace the conversation and some of the duplicates.

The work around suggested for Chrome/Safari/Firefox looks like this:

directive('changeOnKeyup', function changeOnKeyupDirective() {
  return function changeOnKeyupPostLink(scope, elem) {
    elem.on('keyup', elem.triggerHandler.bind(elem, 'change'));
  };
});

Edit:

The OP's issue in the comments above was closed as a duplicate for this reason.

来源：https://stackoverflow.com/questions/31953009/select-element-in-angular-not-updating-modelvalue-on-second-selection

标签

javascript

angularjs

html-select