Plack:...e::File(3pm)

💖 Plack::Session::Store::File — the perl manual page (3pm), bestie edition 💖

okay so welcome to the Plack::Session::Store::File page, straight out of the User Contributed Perl Documentation. yes it's a section 3pm manual, yes it's a whole vibe, and yes I'm gonna walk you through every single line of it. 🎀

---

✨ NAME ✨

Plack::Session::Store::File — it's a Basic file-based session store. that's the whole name, that's the whole job. 💅

---

✨ SYNOPSIS ✨

okay bestie here's the moment. first you import the goods:

use Plack::Builder;
use Plack::Middleware::Session;
use Plack::Session::Store::File;

then a lil app, just to have something to wrap:

my $app = sub {
    return [ 200, [ 'Content-Type' => 'text/plain' ], [ 'Hello Foo' ] ];
};

now the builder, with the default store situation:

builder {
    enable 'Session',
        store => Plack::Session::Store::File->new(
            dir => '/path/to/sessions'
        );
    $app;
};

and now the glow-up version, with custom serializer/deserializer:

# with custom serializer/deserializer

builder {
    enable 'Session',
        store => Plack::Session::Store::File->new(
            dir          => '/path/to/sessions',
            # YAML takes it's args the opposite order
            serializer   => sub { YAML::DumpFile( reverse @_ ) },
            deserializer => sub { YAML::LoadFile( @_ ) },
        );
    $app;
};

not me reading that comment about YAML taking its args in the opposite order like 👀 — it's right there in the source, so it's right there in your version too. no cap.

---

✨ DESCRIPTION ✨

so what is this actually doing 🦋 it implements a basic file based storage for session data. by default it's gonna reach for Storable to serialize and deserialize the data — that's the OOTB behaviour — but it's super easy to configure it otherwise, which is lowkey the whole point.

and for the record: this is a subclass of Plack::Session::Store and it implements its full interface. so anything that expects a Plack::Session::Store, this thing fits right in. periodt. 💅

---

✨ METHODS ✨

🌸 new ( %params )

this is the constructor, the main character entry point. the %params can include the dir, serializer and deserializer options — we'll get to each of them in a sec.

also it will check to be sure that the dir is writeable for you. considerate queen behaviour honestly. 🫶

🌸 dir

this is the directory where the session data files get stored. and if you provide absolutely nothing? then File::Spec's tmpdir() is used to figure out the system's temp dir. convenient ✨

🌸 serializer

this is a CODE reference that implements the serialization logic. the CODE ref gets two arguments:

• the $value — which is a HASH reference to be serialized
• and the $file_path to save it to

and heads up: it is not expected to return anything. it's giving void, not value. 💀

🌸 deserializer

this is a CODE reference that implements the deserialization logic. the CODE ref gets one argument:

• the $file_path to load the data from

and it is expected to return a HASH reference. so unlike its serializing sibling, this one has to give something back. give it up for reciprocity. 👑

---

✨ BUGS ✨

okay bestie, real talk 🍓 — All complex software has bugs lurking in it, and this module is no exception. yes, the original says that, and it's true and it's humbling.

so if you find a bug: either email me, or add the bug to cpan-RT. those are the two options, pick your fighter. 🙈

---

✨ AUTHOR ✨

Stevan Little <stevan.little@iinteractive.com> — the icon, the legend, the author. 💜

---

✨ COPYRIGHT AND LICENSE ✨

Copyright 2009, 2010 Infinity Interactive, Inc.

<http://www.iinteractive.com>

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. slay, honestly. 🎀

---

and that's the whole page, bestie!! no sections skipped, no options dropped, every argument and default and CODE ref accounted for. 🌈

this little time capsule comes from the perl v5.40.1 docs, dated 2025-08-10, and it lives under the name Plack:...e::File(3pm) in the User Contributed Perl Documentation. stay hydrated, serialize responsibly, and go read the SEE ALSOs next time — except there aren't any here, so like. go touch some grass instead. 💅✨🦋