Apache::FakeRequest is used to set up an empty Apache request object that can be used for debugging. The Apache::FakeRequest methods just set internal variables with the same names as the methods and returns the values of the internal variables. Initial values for methods can be specified when the object is created. The print( ) method prints to STDOUT.

Subroutines for Apache constants are also defined so that you can use Apache::Constants while debugging, although the values of the constants are hardcoded rather than extracted from the Apache source code.

Example 21-2 is a very simple module that prints a brief message to the client's browser.

Example 21-2. Book/Example.pm

package Book::Example;
use Apache::Constants qw(OK);

sub handler {
    my $r = shift;
    $r->send_http_header('text/plain');
    print "You are OK ", $r->get_remote_host, "\n";
    return OK;
}

1;

You cannot debug this module unless you configure the server to run it, by calling its handler from somewhere. So, for example, you could put in httpd.conf:

<Location /ex>
    SetHandler perl-script
    PerlHandler Book::Example
</Location>

Then, after restarting the server, you could start a browser, request the location http://localhost/ex, and examine the output. Tedious, no?

With the help of Apache::FakeRequest, you can write a little script that will emulate a request and return the output (see Example 21-3).

Example 21-3. fake.pl

#!/usr/bin/perl

use Apache::FakeRequest ( );
use Book::Example ( );

my $r = Apache::FakeRequest->new('get_remote_host'=>'www.example.com');
Book::Example::handler($r);

When you execute the script from the command line, you will see the following output as the body of the response:

You are OK www.example.com

As you can see, when Apache::FakeRequest was initialized, we hardcoded the Apache method get_remote_host( ) with a static value.

At the time of this writing, Apache::FakeRequest is far from being complete, but you may still find it useful.

If while developing your code you have to switch back and forth between the normal and fake modes, you may want to start your code in this way:

use constant MOD_PERL => $ENV{MOD_PERL};

my $r;

if (MOD_PERL) {
    $r = Apache->request;
} else {
    require Apache::FakeRequest;
    $r = Apache::FakeRequest->new;
}

When you run from the command line, the fake request will be used; otherwise, the usual method will be used.