types.py

class DateAttributeType(AttributeType):
    """ Date parsing. """
    # TODO: simplify this, its hell!
    SUFFIX = ('in the format "yyyy-mm-dd", "yyyy-mm" or "yyyy", '
              'e.g. "2011-12-31".')

    def test(self, row, meta):
        value = unicode(self._column_or_default(row, meta))
        end_value = row.get(meta.get('end_column'))
        for value, is_end in [(value, False), (end_value, True)]:
            column = meta.get('end_column' if is_end else 'column')
            if meta['dimension'] != 'time':
                msg = '"%s" can be empty or a value %s' % (column, self.SUFFIX)
                if not value:
                    continue
            else:
                if is_end and not value:
                    continue
            msg = ('"time" (here "%s") has to be %s. The "end_column", if specified, '
                   'might be empty') % (value, self.SUFFIX)
            try:
                for_datestrings(value)
            except:
                return msg
        return True

    
    def cast(self, row, meta):
        value = unicode(self._column_or_default(row, meta))
        end_value = row.get(meta.get('end_column'))
        # TODO: former implementation had the following logic which 
        # this does not fully reproduce:
        #if not value or value == PLACEHOLDER:
        #        if not default:
        #            return EMPTY_DATE
        #        else:
        #            value = default
        if not value:
            value = EMPTY_DATE
        return for_datestrings(value, end_value)