How do I set selected option using angularjs ng-options and ng-model using a strict?

Question

Everything lists out fine, and I have the default value set in the model, but it seems that it just does not want to use that as the default option in the select element. How do I accomplish getting the model to select the corresponding language iso value? Also, how do I keep from an empty option being added to the the select?

Example data:

// list of languages
[
 {"iso":"abk","language":"Abkhazian"},
 {"iso":"aar","language":"Afar"},
 {"iso":"afr","language":"Afrikaans"},
  ...
]

// location object containing the property for the language value
{
    "id":"516",
    "site":"Al Seela",
    "start_utc":"03:00:00",
    "end_utc":"06:00:00",
    ...
    "lang_iso":"eng",
    "language":"English"
}

Markup:

<div ng-controller="StationListController as stationList" ng-init="init()">
    ...
    <div ng-repeat="location in station.locations" class="panel panel-default">
    ...
        <select class="form-control" id="{{'locationLang-' + location.id}}" ng-model="location.lang_iso" ng-options="lang.iso as lang.language for lang in locLanguages track by lang.iso"></select>

JS:

$scope.init = function () {
    $http.get($scope.ajaxurl + '?_mode=languages&_task=list').success(function(data, success) {
        $scope.locLanguages = data;
    }).error(function(error) {});
};

The result:

<select ng-options="lang.iso as lang.language for lang in locLanguages track by lang.iso" ng-model="location.lang_iso" id="locationLang-844" class="form-control ng-pristine ng-valid ng-touched">
    <option value="?" selected="selected"></option>
    <option value="abk" label="Abkhazian">Abkhazian</option>
    <option value="aar" label="Afar">Afar</option>
    <option value="afr" label="Afrikaans">Afrikaans</option>
    ...
</select>

Answer 1

The only way to fix the empty option issue is to assign a default value in your controller. It's pretty standard these days to just use the first value, so just update your $scope.init to:

$scope.init = function () {
    $http.get($scope.ajaxurl + '?_mode=languages&_task=list').success(function(data, success) {
        $scope.locLanguages = data;
        $scope.location.lang_iso = {"iso":"abk","language":"Abkhazian"}; // or perhaps the entire object
    }).error(function(error) {});
};