Trabalhando com o WTForms Fieldlist
$(document).ready(function () {
$('#add_another_button').click(function () {
clone_field_list('fieldset:last');
});
});
function clone_field_list(selector) {
var new_element = $(selector).clone(true);
var elem_id = new_element.find(':input')[0].id;
var elem_num = parseInt(elem_id.replace(/.*-(\d{1,4})-.*/m, '$1')) + 1;
new_element.find(':input').each(function() {
var id = $(this).attr('id').replace('-' + (elem_num - 1) + '-', '-' + elem_num + '-');
$(this).attr({'name': id, 'id': id}).val('').removeAttr('checked');
});
new_element.find('label').each(function() {
var new_for = $(this).attr('for').replace('-' + (elem_num - 1) + '-', '-' + elem_num + '-');
$(this).attr('for', new_for);
});
$(selector).after(new_element);
}
SAMER SAEID