Oracle Database Tips by Donald Burleson

APEX and OWA_COOKIE

The Oracle Web Agent (OWA) packages are not part of the APEX installation, but they do warrant some coverage since APEX uses them.  They are further documented in Oracle document B10802.  The name of the document is PL/SQL Packages and Types Reference.  It is a huge document and a valuable asset to which developers and programmers should have ready access.  The document can be found by using the link at the top of the chapter.

The OWA_COOKIE package deals with browser cookies.  It will write to a cookie and read from a cookie stored on the client machine.  If no date is specified, the cookie only exists during the client's session.

Types used with the OWA_COOKIE package

type vc_arr is table of varchar2(4000)
index by binary_integer. 

type cookie is record (
name varchar2(4000),
vals vc_arr,
num_vals integer); 

owa_cookie.send(
       name in varchar2,
       value in varchar2,
       expires in date default null,
       path in varchar2 default null,
       domain in varchar2 default null,
       secure in varchar2 default null); 

This creates a cookie on the client browser machine.  The expires date should be specified or the cookie only exists during the life of the session.

Example:

begin
   owa_util.mime_header('text/html', FALSE);
   owa_cookie.send(
      name=>'EASY_COOKIE',
      value=>lower(:P2100_COOKIE_SOURCE),
      expires => sysdate + 365); 

   -- Set the cookie and redirect to another page
   owa_util.redirect_url(
'f?p=&APP_ID.:2101:&SESSION.' );
exception
   when others then
      null;
end;

get( name in varchar2) return cookie;

This will return a type of cookie as explained earlier.  It receives the name of the cookie to return.

Example:

declare
    v varchar2(255) := null;
    c owa_cookie.cookie;
begin
   c := owa_cookie.get('LOGIN_USERNAME_COOKIE');
   :P2100_COOKIE_TARGET := c.vals(1);
exception
   when others then
      null;
end;

owa_cookie.remove(
       name in varchar2,
       val in varchar2,
       path in varchar2 default null);

This procedure forces the cookie to expire, which essentially removes its availability to be used.  It does this by setting the expiration date to 01-JAN-1990.

Example:

begin
   owa_cookie.remove(
      name => 'EASY_COOKIE',
      value => NULL);
end;

print_cgi_env

This prints all CGI environment variable's available to the CGI Gateway.  This procedure can be placed directly in a PL/SQL region to display the values of all the CGI variables.  Put the following code in the PL/SQL region:

print_cgi_env;

The above book excerpt is from:

Easy HTML-DB Oracle Application Express

Create Dynamic Web Pages with OAE

ISBN 0-9761573-1-4   

Michael Cunningham & Kent Crotty

http://www.rampant-books.com/book_2005_2_html_db.htm