def get_resources_list(object_dict, resources_list):
    """
    Method to get the list of resources labels

    :param object_dict: dictionary to describe XNAT object parameters
    :param resources_list: list of resources requested from the user
    :return: None if empty, 'all' if all selected, list otherwise
    """
    # Get list of resources' label
    if resources_list == 'all':
        res_list = object_dict('resources', None)
    else:
        res_list = resources_list
    return res_list