Fix a wrong class name

select2_fixed_widgets.py

# WARNING: This is just a workaround.  Consider it as a very
#          temporary solution if you really need this feature.

from django.utils.safestring import mark_safe
from django_select2.util import convert_to_js_arr


TEMPORARY_ID = 0


def selector():
    return """
    $input = $('.select2-%s').nextAll('input:not([id*="__prefix__"])');
    """ % TEMPORARY_ID


def render_js_script(inner_code):
    code = """
    %s
    if ($input.length != 0) {
        %s
    }""" % (selector(), inner_code)
    return u"""
        <script type="text/javascript">
            jQuery(function ($) {
                %s else {
                    setTimeout(function() {
                        $('.add-row a').click(function () {
                            %s
                        });
                    }, 500);
                }
            });
        </script>""" % (code, code)


class FixedSelect2WidgetMixin(object):
    def render_js_code(self, id_, *args):
        if id_:
            return render_js_script(self.render_inner_js_code(id_, *args))
        return u''

    def render(self, name, value, attrs=None, choices=()):
        global TEMPORARY_ID

        s = """
        <span class="select2-%s"></span>
        <script>
            jQuery(function ($) {
                %s
            });
        </script>
        """ % (TEMPORARY_ID, selector())

        s += super(FixedSelect2WidgetMixin, self).render(
            name, value, attrs=attrs, choices=choices)

        id_ = attrs.get('id', None)

        s = s.replace("$('#%s')" % id_, '$input')
        s = s.replace('$("#%s")' % id_, '$input')
        s = s.replace("'%s'" % id_, '$input[0].id')

        TEMPORARY_ID += 1

        return mark_safe(s)


# Now, redefine each widget class you need by adding the mixin
# as the first inherited class.

from django_select2 import AutoHeavySelect2Widget, AutoHeavySelect2MultipleWidget

class AutoHeavySelect2Widget(FixedSelect2WidgetMixin, AutoHeavySelect2Widget):
    pass


class AutoHeavySelect2MultipleWidget(FixedSelect2WidgetMixin, AutoHeavySelect2MultipleWidget):
    def render_inner_js_code(self, id_, name, value, *args):
        js = ''
        if value:
            js += u"$('#%s').val(django_select2.convertArrToStr(%s));" \
                  % (id_, convert_to_js_arr(value, id_))
        js += u"django_select2.initMultipleHidden($('#%s'));" % id_
        js += super(FixedSelect2WidgetMixin, self).render_inner_js_code(
            id_, name, value, *args)
        return js

hi man, your solution is good, but create two fields and first is broken
this block hide first broken field

nemovitost-formset ... formset id

s2id_id_nemovitosti .. base from formset prefix

$("#nemovitost-formset a").click(function(e){

form_index = 0
counter = 1;

$("#nemovitost-formset div").each(function(i, el){
  element =  $(this)
    if (element.prop("id").search("s2id_id_nemovitosti-"+form_index) !== -1 )
    {
      if (counter === 0 )
      {
        element.hide();
        counter = counter + 1;
      }
      else
      {
        counter = 0;
        form_index = form_index + 1;
      }

    }
});