Plack(3pm)

1Plack(3)              User Contributed Perl Documentation             Plack(3)
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NAME

6       Plack - Perl Superglue for Web frameworks and Web Servers (PSGI
7       toolkit)
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DESCRIPTION

10       Plack is a set of tools for using the PSGI stack. It contains
11       middleware components, a reference server and utilities for Web
12       application frameworks. Plack is like Ruby's Rack or Python's Paste for
13       WSGI.
14
15       See PSGI for the PSGI specification and PSGI::FAQ to know what PSGI and
16       Plack are and why we need them.
17

MODULES AND UTILITIES

19   Plack::Handler
20       Plack::Handler and its subclasses contains adapters for web servers. We
21       have adapters for the built-in standalone web server
22       HTTP::Server::PSGI, CGI, FCGI, Apache1, Apache2 and
23       HTTP::Server::Simple included in the core Plack distribution.
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25       There are also many HTTP server implementations on CPAN that have Plack
26       handlers.
27
28       See Plack::Handler when writing your own adapters.
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30   Plack::Loader
31       Plack::Loader is a loader to load one Plack::Handler adapter and run a
32       PSGI application code reference with it.
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34   Plack::Util
35       Plack::Util contains a lot of utility functions for server implementors
36       as well as middleware authors.
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38   .psgi files
39       A PSGI application is a code reference but it's not easy to pass code
40       reference via the command line or configuration files, so Plack uses a
41       convention that you need a file named "app.psgi" or similar, which
42       would be loaded (via perl's core function "do") to return the PSGI
43       application code reference.
44
45         # Hello.psgi
46         my $app = sub {
47             my $env = shift;
48             # ...
49             return [ $status, $headers, $body ];
50         };
51
52       If you use a web framework, chances are that they provide a helper
53       utility to automatically generate these ".psgi" files for you, such as:
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55         # MyApp.psgi
56         use MyApp;
57         my $app = sub { MyApp->run_psgi(@_) };
58
59       It's important that the return value of ".psgi" file is the code
60       reference. See "eg/dot-psgi" directory for more examples of ".psgi"
61       files.
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63   plackup, Plack::Runner
64       plackup is a command line launcher to run PSGI applications from
65       command line using Plack::Loader to load PSGI backends. It can be used
66       to run standalone servers and FastCGI daemon processes. Other server
67       backends like Apache2 needs a separate configuration but ".psgi"
68       application file can still be the same.
69
70       If you want to write your own frontend that replaces, or adds
71       functionalities to plackup, take a look at the Plack::Runner module.
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73   Plack::Middleware
74       PSGI middleware is a PSGI application that wraps an existing PSGI
75       application and plays both side of application and servers. From the
76       servers the wrapped code reference still looks like and behaves exactly
77       the same as PSGI applications.
78
79       Plack::Middleware gives you an easy way to wrap PSGI applications with
80       a clean API, and compatibility with Plack::Builder DSL.
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82   Plack::Builder
83       Plack::Builder gives you a DSL that you can enable Middleware in
84       ".psgi" files to wrap existent PSGI applications.
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86   Plack::Request, Plack::Response
87       Plack::Request gives you a nice wrapper API around PSGI $env hash to
88       get headers, cookies and query parameters much like Apache::Request in
89       mod_perl.
90
91       Plack::Response does the same to construct the response array
92       reference.
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94   Plack::Test
95       Plack::Test is a unified interface to test your PSGI application using
96       standard HTTP::Request and HTTP::Response pair with simple callbacks.
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98   Plack::Test::Suite
99       Plack::Test::Suite is a test suite to test a new PSGI server backend.
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CONTRIBUTING

102   Patches and Bug Fixes
103       Small patches and bug fixes can be either submitted via nopaste on IRC
104       <irc://irc.perl.org/#plack> or the github issue tracker
105       <http://github.com/plack/Plack/issues>.  Forking on github
106       <http://github.com/plack/Plack> is another good way if you intend to
107       make larger fixes.
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109       See also <http://contributing.appspot.com/plack> when you think this
110       document is terribly outdated.
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112   Module Namespaces
113       Modules added to the Plack:: sub-namespaces should be reasonably
114       generic components which are useful as building blocks and not just
115       simply using Plack.
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117       Middleware authors are free to use the Plack::Middleware:: namespace
118       for their middleware components. Middleware must be written in the
119       pipeline style such that they can chained together with other
120       middleware components.  The Plack::Middleware:: modules in the core
121       distribution are good examples of such modules. It is recommended that
122       you inherit from Plack::Middleware for these types of modules.
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124       Not all middleware components are wrappers, but instead are more like
125       endpoints in a middleware chain. These types of components should use
126       the Plack::App:: namespace. Again, look in the core modules to see
127       excellent examples of these (Plack::App::File, Plack::App::Directory,
128       etc.).  It is recommended that you inherit from Plack::Component for
129       these types of modules.
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131       DO NOT USE Plack:: namespace to build a new web application or a
132       framework. It's like naming your application under CGI:: namespace if
133       it's supposed to run on CGI and that is a really bad choice and would
134       confuse people badly.
135

AUTHOR

137       Tatsuhiko Miyagawa
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COPYRIGHT

140       The following copyright notice applies to all the files provided in
141       this distribution, including binary files, unless explicitly noted
142       otherwise.
143
144       Copyright 2009-2013 Tatsuhiko Miyagawa
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CORE DEVELOPERS

147       Tatsuhiko Miyagawa (miyagawa)
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149       Tokuhiro Matsuno (tokuhirom)
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151       Jesse Luehrs (doy)
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153       Tomas Doran (bobtfish)
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155       Graham Knop (haarg)
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CONTRIBUTORS

158       Yuval Kogman (nothingmuch)
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160       Kazuhiro Osawa (Yappo)
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162       Kazuho Oku
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164       Florian Ragwitz (rafl)
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166       Chia-liang Kao (clkao)
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168       Masahiro Honma (hiratara)
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170       Daisuke Murase (typester)
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172       John Beppu
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174       Matt S Trout (mst)
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176       Shawn M Moore (Sartak)
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178       Stevan Little
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180       Hans Dieter Pearcey (confound)
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182       mala
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184       Mark Stosberg
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186       Aaron Trevena
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LICENSE

198       This library is free software; you can redistribute it and/or modify it
199       under the same terms as Perl itself.
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203perl v5.38.0                      2023-07-21                          Plack(3)