问题

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

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

Here is my HTML code

<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>

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;
});

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

回答1:

For reference : Why does angularjs include an empty option in select?

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.

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.

Change your code like this

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>

Working JSFiddle Demo

UPDATE (Dec 31, 2015)

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>

And in JS no need to initialize value.

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

回答2:

While all the suggestions above are working, sometimes I need to have an empty selection (showing placeholder text) when initially enter my screen. So, to prevent select box from adding this empty selection at the beginning (or sometimes at the end) of my list I am using this trick:

HTML Code

<div ng-app="MyApp1">
    <div ng-controller="MyController">
        <input type="text" ng-model="feed.name" placeholder="Name" />
        <select ng-model="feed.config" ng-options="template.value as template.name for template in feed.configs" placeholder="Config">
            <option value="" selected hidden />
        </select>
    </div>
</div>

Now you have defined this empty option, so select box is happy, but you keep it hidden.

回答3:

Here is an updated fiddle: http://jsfiddle.net/UKySp/

You needed to set your initial model value to the actual object:

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

And update your select to look like this:

<select ng-model="feed.config" ng-options="item.name for item in configs">

回答4:

Another method to resolve is by making use of: $first in ng-repeat

Usage:

<select ng-model="feed.config">
    <option ng-repeat="template in configs" ng-selected="$first">{{template.name}}</option>
</select>

References:

ngSelected : https://docs.angularjs.org/api/ng/directive/ngSelected

$first : https://docs.angularjs.org/api/ng/directive/ngRepeat

Cheers

回答5:

It is kind of a workaround but works like a charm. Just add <option value="" style="display: none"></option> as a filler. Like in:

<select size="4" ng-model="feed.config" ng-options="template.value as template.name for template in feed.configs">
       <option value="" style="display: none"></option>
</select>

回答6:

There are multiple ways like -

<select ng-init="feed.config = options[0]" ng-model="feed.config"
        ng-options="template.value as template.name for template in feed.configs">
</select>

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

回答7:

If you just want to remove the blank space use ng-show and you are done! No need to initialize value in JS.

<select ng-model="SelectedStatus" ng-options="x.caption for x in statusList">
    <option value="" ng-show="false"></option>
</select>`

回答8:

Change your code like this. You forget about the value inside option. Before you assign the ng-model. It must have a value. Only then it doesn't get the undefined value.

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

 var MyApp=angular.module('MyApp1',[])
 MyApp.controller('MyController',function($scope) {  
      $scope.feed = 'config1';      
      $scope.configs = [
         {'name': 'Config 1', 'value': 'config1'},
         {'name': 'Config 2', 'value': 'config2'},
         {'name': 'Config 3', 'value': 'config3'}
      ];
 });

回答9:

Use ng-value instead of value.

$scope.allRecs = [{"text":"hello"},{"text":"bye"}];
$scope.X = 0;

and then in html file should be like:

<select ng-model="X">  
     <option ng-repeat="oneRec in allRecs track by $index" ng-value="$index">{{oneRec.text}}</option>
</select>

回答10:

For me the answer to this question was using <option value="" selected hidden /> as it was proposed by @RedSparkle plus adding ng-if="false" to work in IE.

So my full option is (has differences with what I wrote before, but this does not matter because of ng-if):

<option value="" ng-if="false" disabled hidden></option>

回答11:

Finally it worked for me.

<select ng-init="mybasketModel = basket[0]" ng-model="mybasketModel">
        <option ng-repeat="item in basket" ng-selected="$first">{{item}}</option>
</select>

回答12:

Also check whether you have any falsy value or not. Angularjs will insert an empty option if you do have falsy value. I struggled for 2 days just due to falsy value. I hope it will be helpful for someone.

I had options as [0, 1] and initially I was set the model to 0 due to that it was inserted empty option. Workaround for this was ["0" , "1"].

来源：https://stackoverflow.com/questions/20738953/remove-blank-option-from-select-option-with-angularjs

标签

angularjs

angularjs-select

Remove Blank option from Select Option with AngularJS

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