Re: CGI.pm Caching Issue

[btrott]

Are you running under mod_perl or PerlEx?

From a quick glance at the CGI.pm source, it looks like it calls _reset_globals for each new object, if you're running under either of those architectures (mod_perl or PerlEx). Since I believe both of them work similarly--ie. compiling a Perl interpreter into the web server and pre-compiling modules--this would imply that when you're doing "similar" things (only compiling CGI.pm once, or using persistent CGI objects), you'll need to call _reset_globals.

Ah, here it is: this is why you're getting that behavior. In the init subroutine, there's this code:

    # if we get called more than once, we want to initialize
    # ourselves from the original query (which may be gone
    # if it was read from STDIN originally.)
    if (defined(@QUERY_PARAM) && !defined($initializer)) {
        foreach (@QUERY_PARAM) {
            $self->param('-name'=>$_,'-value'=>$QUERY_PARAM{$_});
        }
        return;
    }

So this is initializing your object with the original query, rather than the new (and possibly different) one.

And what does _reset_globals do? It calls initialize_globals, which does this:

    undef @QUERY_PARAM;

There you go. In persistent situations, then, (mod_perl or PerlEx), CGI.pm needs to clean up @QUERY_PARAM--you'll need to fake this in your persistent application, then.

Calling initialize_globals would be another option--plus it's not "private" (no "_"). :)

[takshaka]

Does delete_all not take care of that? It does undef %{$self} on the CGI object.

[chromatic]

No, that won't do it. @QUERY_PARAM is apparently a package variable. Once you have CGI compiled and in memory, @QUERY_PARAM is set until explicitly reset or undefined.

Note in the subroutine, the CGI object $q goes out of scope (and would thus be destroyed) at either of the return statements. btrott has it right -- Jellybean is a persistent environment like PERLEX or mod_perl, but CGI doesn't know that. We have to give it a hand.

[takshaka]

Okay, I was thinking @QUERY_PARAMS was getting reset from the empty param() list somewhere in there, but that doesn't seem to be the case.

I would use the $CGI::PERLEX setting, since all it does it flag _reset_globals() to be called in the constructor and is pretty much a "set it and forget it" thing. Of course, 'undef @CGI::QUERY_PARAM' may be the only method guaranteed to work with future versions.