How to make ng-repeat filter out duplicate results
Or you can write your own filter using lodash.
app.filter('unique', function() {
return function (arr, field) {
return _.uniq(arr, function(a) { return a[field]; });
};
});
You could use the unique filter from AngularUI (source code available here: AngularUI unique filter) and use it directly in the ng-options (or ng-repeat).
<select ng-model="orderProp" ng-options="place.category for place in places | unique:'category'">
<option value="0">Default</option>
// unique options from the categories
</select>