Check if state of dropdown has changed - angularjs

Question

I am using ng-options to display drop-down with options. Suppose I have three options in it for example option1, option2, option3.By default option1 is selected, now if a user selects option2, then $pristine becomes False and again if he selects option1 then from angularjs's prospective $pristine should be false but according to user he has not changed the option.So I was looking for a way to detect this change

Answer 1

Here is the Js fiddle demo
HTML
<div ng-app="myApp">
<div ng-controller="ctrl">
<form name="myForm">
{{myForm.$pristine}}
<select ng-model='list' ng-options='item.name for item in data'>
</select>
</form>
</div>
</div>
JS code
var app = angular.module('myApp', []);
app.controller('ctrl', function($scope) {
$scope.data = [{
id: 1,
name: 'test'
}, {
id: 2,
name: 'test1'
}];
$scope.list = $scope.data[0];
$scope.$watch('list', function(o, n) {
if ($scope.list == $scope.data[0])
$scope.myForm.$pristine = true;
})
});
You have add watch on your list model then this can be achieved

Answer 2

That is exactly what ng-change is for.
Usage would be like this (added $index to show you another option):
HTML
<div ng-app="myApp">
<div ng-controller="listController">
<form name="myForm">
<select ng-model="currOption"
ng-options='item.name for item in data'
ng-change="optionChanged(currOption, $index)">
</select>
</form>
</div>
</div>
Controller
angular.module('myApp')
.controller('listController', function($scope) {
$scope.data = [{
id: 1,
name: 'option1'
}, {
id: 2,
name: 'option2'
}, {
id: 3,
name: 'option3'
}];
$scope.optionChanged(option, index) {
// option = the selection the user just made.
// index = the index of the selection in your data. I.E. $scope.data[index]
};
});