Blank screen rather than error message

Question

I've written some pages using htp which I am using rather than htmldb and calling using the format http://location:port/htmldb/pkg_test.test and this is working well but if there is an error all I get is a white screen rather than anything helpful.
Are the errors written to a log somewhere or is it possible to show an error page displaying the error? I'm just testing on my own so I don't need to worry about what a user would see.
Cheers,
Greg

Answer 1

Hi Greg,
I have a few points here ...
1) You could use a generic exception handler for all procedures that are called directly via url, like this:
CREATE OR REPLACE PROCEDURE test_error IS
   l_i   NUMBER;
BEGIN
   -- should raise ORA-01476: divisor is equal to zero
   l_i := 1 / 0;
EXCEPTION
   WHEN OTHERS THEN
      HTP.p (SQLERRM);
END;
/2) Aside from that you should be able to see the error messages when raising the log level:
Re: http error log
3) Also, when testing the htp/htf output, you might use Raptor ( http://www.oracle.com/technology/software/products/sql/index.html ), owa output is displayed there as well. Whow, early adopter release 3 is available!!!
4) In addition to that you might even use sqlplus to output the result of your stored procedures like this:
set serveroutput on
begin
    owa.init_cgi_env( 0, owa.cgi_var_name, owa.cgi_var_val );
    htp.p('hello world');
    owa_util.showpage;
end;
/Please be aware that you can only access the web context in scenario 1) and 2). I mean access to the CGI - environment like owa_util.get_cgi_env('REMOTE_USER');
Well, in 3) and 4) it is still possible to set the environment manually ;).
Hope that helps,
~Dietmar.