convert hex colors to mapserver format in postgresql

hexcolor_to_mapserver.sql

create or replace function public.hexcolor_to_mapserver(hexcolor text) returns text as
$body$
declare
	thexcolor text;
	color_r int;
	color_g int;
	color_b int;
begin
	thexcolor := trim(both ' ' from hexcolor);
	if not thexcolor ~ '^#[0-9a-fA-F]{6}$' then
		raise exception 'the given value does not appear to be a valid hex color representation';
	end if;

	-- need to used excute for dynamic casting :(
	execute 'select x''' || substring(thexcolor,2,2) || '''::int;' into color_r;
	execute 'select x''' || substring(thexcolor,4,2) || '''::int;' into color_g;
	execute 'select x''' || substring(thexcolor,6,2) || '''::int;' into color_b;
	
	return color_r::text || ' ' || color_g::text || ' ' || color_b::text;
end
$body$ LANGUAGE plpgsql VOLATILE;
COMMENT ON FUNCTION public.hexcolor_to_mapserver(text) IS 'convert a hex color represantation to a mapserver compatible one with a string containing three integer values.';