'Overrides S3FilterWidget.data_element(), constructs multiple
hidden INPUTs (one per variable) with element IDs of the form
<id>-<operator>-data (where no operator is translated as "eq").
@param variables: the variables'

def data_element(self, variables):

    fields = self.field
    if (type(fields) is not list):
        return super(S3DateFilter, self).data_element(variables)
    selectors = self.selector.split('|')
    operators = self.operator
    elements = []
    _id = self.attr['_id']
    start = True
    for selector in selectors:
        if start:
            operator = operators[0]
            start = False
        else:
            operator = operators[1]
        variable = self._variable(selector, [operator])[0]
        elements.append(INPUT(_type='hidden', _id=('%s-%s-data' % (_id, operator)), _class=('filter-widget-data    %s-data' % self._class), _value=variable))
    return elements
