'Gets Recurrence rule string according to value type RECUR of iCalendar from the values given.
:return dictionary of rrule value.'

@api.depends('byday', 'recurrency', 'final_date', 'rrule_type', 'month_by', 'interval', 'count', 'end_type', 'mo', 'tu', 'we', 'th', 'fr', 'sa', 'su', 'day', 'week_list')
def _compute_rrule(self):

    for meeting in self:
        if meeting.recurrency:
            meeting.rrule = meeting._rrule_serialize()
        else:
            meeting.rrule = ''
