Get and set apache request notes
(PHP 4, PHP 5)
Code Examples / Notes » apache_note
Used this with mod_layout... very handy. :) Used my PHP code in my header to check session variables and validate the session. If the session is not valid, I use apache_note to tell mod_layout not to display the content page or the footer, just the error page I generate in the header page.
Note: successive calls to apache_note with the same KEY overwrite the VALUE. Ie:
Will only send the last note. You need to do something like:
To get both variables through. How you retrieve this is obviously up to the module receiving notes, of course...
This function is a wrapper for Apache's table_get and table_set. It
edits the table of notes that exists during a request. The table's
purpose is to allow Apache modules to communicate. Here are some
further details I found in the mailing list archives:
The main use for apache_note() is to pass information
from one module to another within the same request. I haven`t seen an
actual implementation that uses this yet, but it is quite possible for
someone to write a module which performs some sort of action at one of the
other stages of the request and stores some information in the Apache note
table which will then be available to PHP when the request reaches the
content-handling stage. Or, one could have a logging module that reads
something from the Apache Note table set by PHP.
David Sklar wrote:
You can use it to facilitate communication between modules that act on the
request at different stages. I use it to record userids in logfiles. In
some PHP that gets auto_prepend-ed, I do a
(where $sessionID has been slurped out of a cookie and processed)
and then, in my httpd.conf, part of my LogFormat is
so that sessionID gets written to the logfile.
If you have other modules that process the request before or after PHP
does (authentication, fixups, whatever..) you can have them talk to PHP or
PHP talk to them through the notes table.
fredrik dot ekengren
In a project I was involved in, we needed to pass data from mod_php4 to mod_perl. We used apache_note() to do the work for us.
It took a little while to figure it out, but here's some sample code that could help anyone with the same problem.
From PHP file:
// Put all post variables into apache notes
while (list($key,$value) = each($HTTP_POST_VARS))
// Call perl script
$result = apache_note("resultdata");
From Perl file:
# Get Apache request object
my $r = Apache->request()->main();
# Get passed data
my $name = $r->notes('name');
my $more_data = $r->notes('more_data');
# some processing
# Pass result back to PHP
apache_note() does not work on requests to a symlink, only on actual files. Eg. if index.php is symlinked to login.php, then any apache_note() in login.php will not be available to other apache modules such as logging.