Select2 - 当回调没有值时如何设置占位符

Question

我想在select2中设置初始值，但是如果没有初始值，我想设置占位符而不是值。这是我的代码：

Javascript：

$(".neighborhood").select2({
    language: "en",
    placeholder: "Find your region ...",
    allowClear: true,
    data: $scope.regions,
    initSelection: function(element, callback) {
        var userNeighborhood = $cookies.get("neighborhoodInfo");
        if (!isUndefinedOrNull(userNeighborhood)) {
            console.log('user neighborhood is not null or undefined');
            userNeighborhood = userNeighborhood.split(',');
            var initialVal = {
                'text': userNeighborhood[0],
                'id': userNeighborhood[1],
            };
            callback(initialVal);
        } else {
            console.log('user neighborhood is null or undefined ');
        }
    }
});
var isUndefinedOrNull = function(val) {
   return angular.isUndefined(val) || val === null
};

HTML：

<select class="neighborhood js-states form-control" >
    <option value=""></option>
</select>   

每当 userNeighborhood 不为null或未定义时， select2 的输入将被属性值替换。实际上，当 userNeighborhood 未定义时，它不会设置占位符。

如何解决？

Answer 1

<select class="neighborhood js-states form-control" data-placeholder="Your Placeholder" >

$('.neighborhood').select2({
minimumResultsForSearch: -1,
placeholder: function(){
    $(this).data('placeholder');
}
});