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Why does AngularJS include an empty option in select?

I've been working with AngularJS for the last few weeks, and the one thing which is really bothering me is that even after trying all permutations or the configuration defined in the specification at http://docs.angularjs.org/api/ng.directive:select, I still get an empty option as the first child of select element.

Here's the Jade:

select.span9(ng-model='form.type', required, ng-options='option.value as option.name for option in typeOptions');

Here the controller:

$scope.typeOptions = [
    { name: 'Feature', value: 'feature' },
    { name: 'Bug', value: 'bug' },
    { name: 'Enhancement', value: 'enhancement' }
];

Finally, here's the HTML which gets generated:

<select ng-model="form.type" required="required" ng-options="option.value as option.name for option in typeOptions" class="span9 ng-pristine ng-invalid ng-invalid-required">
    <option value="?" selected="selected"></option>
    <option value="0">Feature</option>
    <option value="1">Bug</option>
    <option value="2">Enhancement</option>
</select>

What do I need to do to get rid of it?

P.S.: Things work without this as well, but it just looks odd if you use select2 without multiple selection.


p
pkozlowski.opensource

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.

If you want to get rid of the empty option just select an initial value in your controller, something like:

$scope.form.type = $scope.typeOptions[0].value;

Here is the jsFiddle: http://jsfiddle.net/MTfRD/3/

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.


I tried with both $scope.form.type = ''; and $scope.form.type = $scope.typeOptions[0], however I still se this -
Sometimes it really doesn't make sense to have this data in the JS. If it's the server that made the decision about what was in that select, why should the JS have to duplicate it?
This unfortunately doesn't work if you are using an array and null is one of your values.
Is it possible to add a text inside the empty <option> so tat angular generated something like <option value="?">Select an option</option>
@Tareck117 just wirte <option value="">Select an option</option> thats the null-Value of the optionlist. No need for ?-character.
M
Mark Rajcok

If you want an initial value, see @pkozlowski.opensource's answer, which FYI can also be implemented in the view (rather than in the controller) using ng-init:

<select ng-model="form.type" required="required" ng-init="form.type='bug'"
  ng-options="option.value as option.name for option in typeOptions" >
</select>

If you don't want an initial value, "a single hard-coded element, with the value set to an empty string, can be nested into the element. This element will then represent null or "not selected" option":

<select ng-model="form.type" required="required"
  ng-options="option.value as option.name for option in typeOptions" >
    <option style="display:none" value="">select a type</option>
</select>

@hugo, working fiddle: jsfiddle.net/4qKyx/1 Note that "select a type" is shown, but there is no value associated with it. And once you select something else, you won't see it again. (Test on Chrome.)
@MarkRajcok - excellent suggestion! i have stumbled on another issue using your example with transcluding directive. Could you please have a look? plnkr.co/edit/efaZdEQlNfoDihk1R1zc?p=preview
Problem with this is you can still select with keyboard, see stackoverflow.com/a/8442831/57344 solution
This may work for now, but the angular documentation specifically recommends against using ng-init for anything besides ng-repeat - see docs.angularjs.org/api/ng/directive/ngInit
Does not work in IE10, the "select a type" is always visible and selectable.
W
WTK

Angular < 1.4

For anyone out there that treat "null" as valid value for one of the options (so imagine that "null" is a value of one of the items in typeOptions in example below), I found that simplest way to make sure that automatically added option is hidden is to use ng-if.

<select ng-options="option.value as option.name for option in typeOptions">
    <option value="" ng-if="false"></option>
</select>

Why ng-if and not ng-hide? Because you want css selectors that would target first option inside above select to target "real" option, not the one that's hidden. It gets useful when you're using protractor for e2e testing and (for whatever reason) you use by.css() to target select options.

Angular >= 1.4

Due to the refactoring of the select and options directives, using ng-if is no longer a viable option so you gotta turn to ng-show="false" to make it work again.


Should be the accepted answer, because this is the correct visual behavior for the select. You put size="5" to the selects attributes and you can see that there is nothing selected! Like in a default <select>-Element! I can't understand why angular is doing such thing for selects without multiple attribute...
Yes i agree, this should be the accepted answer. This is the 'angular-way'. ng-if actually removes the options element from the dom (when false) so this solution also works on all browsers without 'hacky' coding (contrary to ng-hide or ng-show).
@Sander_P by definition this solution is "hacky" coding in my opinion (putting something in the dom to trick angular into taking it out), but you're right it still is the "best" solution. The "even better" solution would be to allow for a friggin select that has no value! What the heck? Its not like this is an edge scenario.
@dudewad: things might work better with Angular 1.4. From the AngularJS blog for 1.4.0: "ngOptions was completely refactored to allow a number of annoying bugs to be fixed,"
Haha "annoying bugs". Okay. Well I'm still a little skiddish when it comes to upgrading 3 days before delivery so I'll keep with your solution for now, which seems to be working swimmingly. Noted for the future, though :) Thanks!
A
Adam K Dean

Maybe useful for someone:

If you want to use plain options instead of ng-options, you could do like below:

<select ng-model="sortorder" ng-init="sortorder='publish_date'">
  <option value="publish_date">Ascending</option>
  <option value="-publish_date">Descending</option>
</select>

Set the model inline. Use ng-init to get rid of empty option


I haven't been able to find a clear example of setting up ng-options with OBJECTS rather than JSON arrays and when I try to "translate" between the two, not only does it not come out right but it fails "silently" so I haven't a clue what I'm doing wrong. I finally opted for plain ng-repeat in an option tag. I know it's not best practice but at least it WORKS. If anyone can point me to a straightforward, easily swappable on the details, angular-n00b-friendly WORKING example using ng-options with data objects (NOT JSON), I'd be elated. Double elated if it uses ng-init as well.
I am using plain options, but in the controller i dont seem to get the value of selected dropdown. Ex:I tried alert($scope.sortorder.value); and alert($scope.sortorder); both gives undefined. How to get the selected value here?
Thank you so much for this. I was about to write a completely useless object in the controller that I didn't need I just needed a simple select.. Thank you once again.
N
Nabil Boag

Something similar was happening to me too and was caused by an upgrade to angular 1.5.ng-init seems to be being parsed for type in newer versions of Angular. In older Angular ng-init="myModelName=600" would map to an option with value "600" i.e. <option value="600">First</option> but in Angular 1.5 it won't find this as it seems to be expecting to find an option with value 600 i.e <option value=600>First</option>. Angular would then insert a random first item:

<option value="? number:600 ?"></option>

Angular < 1.2.x

<select ng-model="myModelName" ng-init="myModelName=600">
  <option value="600">First</option>
  <option value="700">Second</option>
</select>

Angular > 1.2

<select ng-model="myModelName" ng-init="myModelName='600'">
  <option value="600">First</option>
  <option value="700">Second</option>
</select>

Thanks! In my case I can't use ng-init (no default value) so I casted my model to a string and it worked!
Very useful to my application production issue. Thanks @Nabil Boag
This works, sure, but the better options is to use ng-value="600" in the option instead of value. It will parse it to an number and you dont have to convert your values like you do now :)
@Max I tried a lot of high value answers but none worked until I found yours. Thank you.
C
Community

Among the multitudes of answers here, I figured I'd repost the solution that worked for me and met all of the following conditions:

provided a placeholder/prompt when the ng-model is falsy (e.g. "--select region--" w. value="")

when ng-model value is falsy and user opens the options dropdown, the placeholder is selected (other solutions mentioned here make the first option appear selected which can be misleading)

allow the user to deselect a valid value, essentially selecting the falsy/default value again

https://i.stack.imgur.com/MGEh5.png

code

<select name="market_vertical" ng-model="vc.viewData.market_vertical"
    ng-options="opt as (opt | capitalizeFirst) for opt in vc.adminData.regions">

    <option ng-selected="true" value="">select a market vertical</option>
</select>

src

original q&a - https://stackoverflow.com/a/32880941/1121919


Do you mean if the default is <option ng-selected="true" value="null">?
I mean if ng-model value is setted as null, angular creates and empty option on the select
K
K K

A quick solution:

select option:empty { display:none }

Hope it helps someone. Ideally, the selected answer should be the approach but if in case that's not possible then should work as a patch.


Per my testing this will only work in Chrome (new Chrome, on top of that) and Firefox. IE and Safari break. Don't know about opera and other edge browsers. Either way, this is not a good solution, unfortunately.
where should we place that in html before the close of