File Coverage

blib/lib/Plack/Middleware/ESI.pm

Criterion	Covered	Total	%
statement	80	86	93.0
branch	21	32	65.6
condition	1	3	33.3
subroutine	14	14	100.0
pod	1	1	100.0
total	117	136	86.0

package Plack::Middleware::ESI;
use strict;
use warnings;
our $VERSION = '0.1';
use parent qw(Plack::Middleware);
use Plack::Util;
use Plack::Request;
use LWP::UserAgent;
use HTTP::Request;
use HTTP::Message::PSGI;

sub call {
    my ($self, $env) = @_;
    my $res = $self->app->($env);
    $self->response_cb($res, sub {
        my $res = shift;
        my $h = Plack::Util::headers($res->[1]);
        my $r = Plack::Request->new($env);
        my $ct = $h->get('Content-Type');
        if ($ct =~ /^text\// || $ct =~ /^application\/xh?t?ml\b/) { #"{}
            return sub {
                my $chunk = shift;
                return unless defined $chunk;
                return $self->_process_esi($chunk, $r);
            };
        }
    });
}

sub _process_esi {
    my ($self, $chunk, $r) = @_;
    my $chk_rx = qr{
    return $chunk unless $chunk =~ $chk_rx;
    my $rem_rx = qr{.*?}; #"{}
    my $cmt_rx = qr{}; #"{}
    my $inc_rx = qr{(]+?src="([^"]+)"[^>]*/>)}; #"{}
    $chunk =~ s/$rem_rx//gs;
    $chunk =~ s/$cmt_rx/$1/gs;
	while ($chunk =~ $inc_rx) {
		my $esi = $1;
		my $url = $2;
        my $content = $self->_get_content($url, $r);
        $chunk =~ s/\Q$esi\E/$content/g;
	}
    return $chunk;
}

sub _expand_url {
    my ($self, $url, $r) = @_;
    my $prefix = $r->scheme . '://localhost:' . $r->port;
    if ($url =~ m{^/}) {
        return $prefix . $url;
    }
    else {
        my $path = $r->path;
        $path .= '/' unless $path =~ /\/$/;
        return $prefix . $path . $url;
    }
}

sub _get_content {
    my ($self, $url, $r) = @_;
    my $expanded_url = $url;
    unless ($url =~ m{^https?://}) {
        $expanded_url = $self->_expand_url($url, $r);
    }
    my $content = '';
    eval {
        if ($url ne $expanded_url) { # internal request
            my $httpreq = HTTP::Request->new(GET=>$url);
            $httpreq->uri->scheme('http') unless defined $httpreq->uri->scheme;
            $httpreq->uri->host('localhost') unless defined $httpreq->uri->host;
            my $reqenv = $httpreq->to_psgi;
            my $resp = HTTP::Response->from_psgi($self->app->($reqenv));
            $resp->request($httpreq);
            $content = $resp->content if $resp->code == 200;
        }
        unless ($content) { # external request (or retrying an apparently internal req)
            my $resp = $self->_ua->get($expanded_url);
            if ($resp->code == 200) {
                $content = $resp->content;
            }
            elsif ($r->logger) {
                $r->logger->({level=>'warning', message=>"ESI: URL $expanded_url returned non-OK status code " . $resp->code});
            }
        }
    };
    if ($@) {
        if ($r->logger) {
            $r->logger->({level=>'warning', message=>"ESI: ERROR while fetching $url: $@"});
        }
    }
    return $content;
}

sub _ua {
    my $self = shift;
    return $self->{_ua} if $self->{_ua};
    my $ua = LWP::UserAgent->new;
    $ua->timeout(10);
    $self->{_ua} = $ua;
    return $ua;
}


1;

__END__