--
-- category_synonym__convert_string/1
--
create or replace function category_synonym__convert_string(
  character varying
) returns varchar as $$

-- return string to build search index
declare
        p_name		alias for $1;
        v_index_string	varchar(200);
begin
	-- convert string to uppercase and substitute special chars
        -- TODO: complete
        v_index_string := upper (
                        replace (
                        replace (
                        replace (
                        replace (
                        replace (
                        replace (
			replace (p_name, 'ä', 'AE'), 
					 'Ä', 'AE'),
					 'ö', 'OE'),
					 'Ö', 'OE'),
					 'ü', 'UE'),
					 'Ü', 'UE'),
					 'ß', 'SS'));
					  
	return (' ' || v_index_string || ' ');
end;$$ language plpgsql;