使用AngularJS从选择选项中删除空白选项 [英] Remove Blank option from Select Option with AngularJS

问题描述

我是AngularJS的新手.我进行了很多搜索，但是并不能解决我的问题.

I am new to AngularJS. I searched a lot, but it does not solve my problem.

我第一次在选择框中得到一个空白选项.

I am getting a blank option for the first time in select box.

这是我的HTML代码

<div ng-app="MyApp1">
    <div ng-controller="MyController">
        <input type="text" ng-model="feed.name" placeholder="Name" />
        <select ng-model="feed.config">
            <option ng-repeat="template in configs">{{template.name}}</option>
        </select>
    </div>
</div>

JS

var MyApp=angular.module('MyApp1',[])
MyApp.controller('MyController', function($scope) {
    $scope.feed = {};

      //Configuration
      $scope.configs = [
                                 {'name': 'Config 1',
                                  'value': 'config1'},
                                 {'name': 'Config 2',
                                  'value': 'config2'},
                                 {'name': 'Config 3',
                                  'value': 'config3'}
                               ];
      //Setting first option as selected in configuration select
      $scope.feed.config = $scope.configs[0].value;
});

但是它似乎不起作用. 我该如何解决?这是 JSFiddle演示

But it doesn't seem to work. How can I get this solved? Here is JSFiddle Demo

推荐答案

供参考:为什么angularjs在select <中包含空选项?

当ng-model引用的值在传递给ng-options的一组选项中不存在时，将生成空的option.这样做是为了防止意外选择模型:AngularJS可以看到初始模型未定义或不在选项集中，并且不想自己决定模型的值.

The empty option is generated when a value referenced by ng-model doesn't exist in a set of options passed to ng-options. This happens to prevent accidental model selection: AngularJS can see that the initial model is either undefined or not in the set of options and don't want to decide model value on its own.

简而言之:空选项意味着没有选择有效的模型(有效的意思是:从选项集中).您需要选择一个有效的模型值来摆脱此空选项.

In short: the empty option means that no valid model is selected (by valid I mean: from the set of options). You need to select a valid model value to get rid of this empty option.

像这样更改代码

var MyApp=angular.module('MyApp1',[])
MyApp.controller('MyController', function($scope) {
  $scope.feed = {};

  //Configuration
  $scope.feed.configs = [
    {'name': 'Config 1',
     'value': 'config1'},
    {'name': 'Config 2',
     'value': 'config2'},
    {'name': 'Config 3',
     'value': 'config3'}
  ];
  //Setting first option as selected in configuration select
  $scope.feed.config = $scope.feed.configs[0].value;
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div ng-app="MyApp1">
  <div ng-controller="MyController">
    <input type="text" ng-model="feed.name" placeholder="Name" />
    <!-- <select ng-model="feed.config">
<option ng-repeat="template in configs">{{template.name}}</option>
</select> -->
    <select ng-model="feed.config" ng-options="template.value as template.name for template in feed.configs">
    </select>
  </div>
</div>

工作中的JSFiddle演示

更新(2015年12月31日)

如果您不想设置默认值并想删​​除空白选项，

If You don't want to set a default value and want to remove blank option,

<select ng-model="feed.config" ng-options="template.value as template.name for template in feed.configs">
      <option value="" selected="selected">Choose</option>
</select>

并且在JS中无需初始化值.

And in JS no need to initialize value.

$scope.feed.config = $scope.feed.configs[0].value;

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