dependent dropdown for update缺省情况下加载Laravel中的所有状态

public static function getAllStatuses()
{
    return self::all();
}

public function getOptionsByStatus($statusId)
{
    return $this->where('status_id', $statusId)->get();
}

public function getOptionsByStatus(Request $request)
{
    $statusId = $request->input('status_id');
    $options = Entity::getOptionsByStatus($statusId);
    return response()->json($options);
}

$('#status').change(function() {
    var statusId = $(this).val();
    $.ajax({
        url: '/get-options-by-status',
        type: 'GET',
        data: {status_id: statusId},
        success: function(response) {
            // 更新实体下拉框的选项
            $('#entity').empty();
            $.each(response, function(key, value) {
                $('#entity').append('<option value="' + value.id + '">' + value.name + '</option>');
            });
        }
    });
});