Reset select to default value with AngularJS - angularjs

Question

I have a following question for AngularJS. I have a
select with options created with ngOptions. I want to
set selected option back to default option. I tried to
delete model variable e.g:
if(angular.isDefined($scope.first)){
delete $scope.first;
}
But this not working. Here is my html.
<div ng-app="app">
<div ng-controller="testCtrl">
<select data-ng-model="first" data-ng-options="item.name for item in selectContent" required="required">
<option value="" style="display: none;">-- select --</option>
</select>
{{first.value}}
<hr/>
<input type="button" value="reset dropdown" data-ng-click="resetDropDown()"/>
</div>
</div>
And here is my JavaScript code:
angular.module('app', []).controller('testCtrl', function ($scope) {
$scope.selectContent = [
{
name: "first",
value: "1"
},
{
name: "second",
value: "2"
}
];
$scope.resetDropDown = function() {
if(angular.isDefined($scope.first)){
delete $scope.first;
}
}
});
Here is working jsfiddle:
http://jsfiddle.net/zono/rzJ2w/
How I can solve this problem?
Best regards.

Answer 1

Your reset-button is placed outside of the div containing your controller. This means that your reset-function does not exist in the context where you try to use it.
Change to:
<div ng-app="app">
<div ng-controller="testCtrl">
<select data-ng-model="first" data-ng-options="item.name for item in selectContent" required="required">
<option value="" style="display: none;">-- select --</option>
</select>
{{first.value}}
<hr/>
<input type="button" value="reset dropdown" data-ng-click="resetDropDown()"/>
</div>
</div>
It's always a good idea to use a debugger to make sure the code you're trying to fix is actually being executed.

Answer 2

$scope.resetDropDown = function() {
$scope.first = "";
}

Answer 3

Solution above works for Windows and Android, but did not work for iOS browsers. Probably events are happening in different order there.
So for my code I:
created ID for select element, so I could easily find it by
iQuery;
created delayed invocation of to statements to ensure the
reset is happenning at the very end;
and just in case was
resetting in two ways (but just first way was actually enough in iOS
too);
function resetDropDown () {
$timeout(function(){
$scope.first = '';
// jQuery way
$('select#idOfSelectElement option:first' ).prop( 'selected', true );
}, 200);
}