NAME
Plack::Middleware::EasyHooks - PSGI Middleware the easy way
SYNOPSIS
package Plack::Middleware::MyAccessLog;
use parent qw(Plack::Middleware::EasyHooks);
sub before {
my ($self, $env) = @_;
$env->{MyAccessLog} = {
start_time => time(),
response_size => 0,
};
}
sub filter {
my ($self, $env, $chunk) = @_;
$env->{MyAccessLog]->{response_size} += length $chunk;
return $chunk;
}
sub finalize {
my ($self, $env) = shift;
my $time = time() - $env->{MyAccessLog}->{start_time};
my $size = $env->{MyAccessLog}->{response_size};
warn "Request took $time seconds and sent $size bytes";
}
1;
Or as an inline middleware
use Plack::Builder;
my $app = ...;
builder {
enable 'Plack::Middleware::EasyHooks',
before => sub { $_[0]->{start_time} = time(); },
finalize => sub {
my $time = time() - $_[0]->{start};
warn "Request took $time seconds";
};
$app;
}
DESCRIPTION
Plack::Middleware::EasyHooks takes care of the complexities handling
streaming in PSGI middleware. Just provide hooks to be called before,
during and after the wrapped PSGI application.
The hooks are called in the following order (much simplified):
before();
$app->();
after();
filter($_) for @body;
tail($env);
finalize();
SUPPORTED HOOKS
The following methods are available for hooking into the request
handling
before( $env )
This method is called before processing the wrapped PSGI
application. It receives the PSGI $env hash ref as argument.
The return value is ignored.
after( $env, $res )
This method is called when the app starts to respond. It receives
the PSGI $env and a array ref containing the status code and headers
as arguments.
The middleware can override the status code and headers either by
updating the elements of this array ref or by returning a array ref
with the new status code and headers.
filter ( $env, $chunk )
This method allows you to filter the content of the response. It is
called on each chunk of the response.
The return value is passed to the next level. If the return value is
"undef" proccessing of the request is stopped.
tail( $env );
This methods allows you to add some additional content at the end of
the body.
finalize( $env )
This method is called after the request has been processed.
BUGS
Unless your PSGI server supports cleanup handles, the finalize() method
might be calles before the final chunk is successfully sent to the
client.
AUTHOR
Peter Makholm <peter@makholm.net>
COPYRIGHT AND LICENSE
Copyright (C) 2012 by Peter Makholm.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.