LWP::UserAgent::Cached and If-Modified-Since header

cache-if-modified.pl

use strict;
use LWP::UserAgent::Cached 0.06;
use HTTP::Date;

mkdir '/tmp/cache';
my $ua = LWP::UserAgent::Cached->new(cache_dir => '/tmp/cache');

$ua->nocache_if(sub {
	my $resp = shift;
	$resp->code == 304; # do not cache not modified
});

$ua->recache_if(sub {
	my ($resp, $cached_file_path, $req) = @_;
	
	if ($req->header('Cache-Control') eq 'no-cache') {
		# bypass caching
		return 1;
	}
	
	# try to recache always by sending If-Modified-Since header
	$req->header('If-Modified-Since', time2str((stat($cached_file_path))[9]));
	1;
});

$ua->get("http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"); # test it