man AnyEvent::HTTPD (3): A simple lightweight event based web (application) server

VERSION

Version 0.93

SYNOPSIS

use AnyEvent::HTTPD;
my $httpd = AnyEvent::HTTPD->new (port => 9090);
$httpd->reg_cb (
'/' => sub {
my ($httpd, $req) = @_;
$req->respond ({ content => ['text/html',
"<html><body><h1>Hello World!</h1>"
. "<a href=\"/test\">another test page</a>"
. "</body></html>"
]});
},
'/test' => sub {
my ($httpd, $req) = @_;
$req->respond ({ content => ['text/html',
"<html><body><h1>Test page</h1>"
. "<a href=\"/\">Back to the main page</a>"
. "</body></html>"
]});
},
);
$httpd->run; # making a AnyEvent condition variable would also work

DESCRIPTION

This module provides a simple HTTPD for serving simple web application interfaces. It's completely event based and independend from any event loop by using the AnyEvent module.

It's HTTP implementation is a bit hacky, so before using this module make sure it works for you and the expected deployment. Feel free to improve the HTTP support and send in patches!

The documentation is currently only the source code, but next versions of this module will be better documented hopefully. See also the "samples/" directory in the AnyEvent::HTTPD distribution for basic starting points.

FEATURES

support for GET and POST requests.
support for HTTP 1.0 keep-alive.
processing of "x-www-form-urlencoded" and "multipart/form-data" ("multipart/mixed") encoded form parameters.
support for streaming responses.
with version 0.8 no more dependend on LWP for HTTP::Date.
(limited) support for SSL

METHODS

The AnyEvent::HTTPD class inherits directly from AnyEvent::HTTPD::HTTPServer which inherits the event callback interface from Object::Event.

Event callbacks can be registered via the Object::Event API (see the documentation of Object::Event for details).

For a list of available events see below in the EVENTS section.

new (%args)

This is the constructor for a AnyEvent::HTTPD object. The %args hash may contain one of these key/value pairs:

host => $host

The TCP address of the HTTP server will listen on. Usually 0.0.0.0 (the default), for a public server, or 127.0.0.1 for a local server.

port => $port

The TCP port the HTTP server will listen on. If undefined some free port will be used. You can get it via the "port" method.

ssl => $tls_ctx

If this option is given the server will listen for a SSL/TLS connection on the configured port. As $tls_ctx you can pass anything that you can pass as "tls_ctx" to an AnyEvent::Handle object.

Example:

   my $httpd =
      AnyEvent::HTTPD->new (
         port => 443,
         ssl  => { cert_file => "/path/to/my/server_cert_and_key.pem" }
      );

Or:

   my $httpd =
      AnyEvent::HTTPD->new (
         port => 443,
         ssl  => AnyEvent::TLS->new (...),
      );

request_timeout => $seconds

This will set the request timeout for connections. The default value is 60 seconds.

backlog => $int

The backlog argument defines the maximum length the queue of pending connections may grow to. The real maximum queue length will be 1.5 times more than the value specified in the backlog argument.

See also "man 2 listen".

By default will be set by AnyEvent::Socket"::tcp_server" to 128.

connection_class => $class

This is a special parameter that you can use to pass your own connection class to AnyEvent::HTTPD::HTTPServer. This is only of interest to you if you plan to subclass AnyEvent::HTTPD::HTTPConnection.

request_class => $class

This is a special parameter that you can use to pass your own request class to AnyEvent::HTTPD. This is only of interest to you if you plan to subclass AnyEvent::HTTPD::Request.

allowed_methods => $arrayref

This parameter sets the allowed HTTP methods for requests, defaulting to GET, HEAD and POST. Each request received is matched against this list, and a '501 not implemented' is returned if no match is found. Requests using disallowed handlers will never trigger callbacks.

port

Returns the port number this server is bound to.

host

Returns the host/ip this server is bound to.

allowed_methods

Returns an arrayref of allowed HTTP methods, possibly as set by the allowed_methods argument to the constructor.

stop_request

When the server walks the request URI path upwards you can stop the walk by calling this method. You can even stop further handling after the "request" event.

Example:

   $httpd->reg_cb (
      '/test' => sub {
         my ($httpd, $req) = @_;
         # ...
         $httpd->stop_request; # will prevent that the callback below is called
      },
      '' => sub { # this one wont be called by a request to '/test'
         my ($httpd, $req) = @_;
         # ...
      }
   );

run

This method is a simplification of the "AnyEvent" condition variable idiom. You can use it instead of writing:

   my $cvar = AnyEvent->condvar;
   $cvar->wait;

stop

This will stop the HTTP server and return from the "run" method if you started the server via that method!

EVENTS

Every request goes to a specific URL. After a (GET or POST) request is received the URL's path segments are walked down and for each segment a event is generated. An example:

If the URL '/test/bla.jpg' is requestes following events will be generated:

  '/test/bla.jpg' - the event for the last segment
  '/test'         - the event for the 'test' segment
  ''              - the root event of each request

To actually handle any request you just have to register a callback for the event name with the empty string. To handle all requests in the '/test' directory you have to register a callback for the event with the name '/test'. Here is an example how to register an event for the example URL above:

   $httpd->reg_cb (
      '/test/bla.jpg' => sub {
         my ($httpd, $req) = @_;
         $req->respond ([200, 'ok', { 'Content-Type' => 'text/html' }, '<h1>Test</h1>' }]);
      }
   );

See also "stop_request" about stopping the walk of the path segments.

The first argument to such a callback is always the AnyEvent::HTTPD object itself. The second argument ($req) is the AnyEvent::HTTPD::Request object for this request. It can be used to get the (possible) form parameters for this request or the transmitted content and respond to the request.

Along with the above mentioned events these events are also provided:

request => $req

Every request also emits the "request" event, with the same arguments and semantics as the above mentioned path request events. You can use this to implement your own request multiplexing. You can use "stop_request" to stop any further processing of the request as the "request" event is the first thing that is executed for an incoming request.

An example of one of many possible uses:

   $httpd->reg_cb (
      request => sub {
         my ($httpd, $req) = @_;
         my $url = $req->url;
         if ($url->path =~ /\/images\/img_(\d+).jpg$/) {
            handle_image_request ($req, $1); # your task :)
            # stop the request from emitting further events
            # so that the '/images/img_001.jpg' and the
            # '/images' and '' events are NOT emitted:
            $httpd->stop_request;
         }
      }
   );

client_connected => $host, $port

client_disconnected => $host, $port

These events are emitted whenever a client coming from "$host:$port" connects to your server or is disconnected from it.

CACHING

Any response from the HTTP server will have "Cache-Control" set to "max-age=0" and also the "Expires" header set to the "Date" header. Meaning: Caching is disabled.

You can of course set those headers yourself in the response, or remove them by setting them to undef, but keep in mind that the default for those headers are like mentioned above.

If you need more support here you can send me a mail or even better: a patch :)

AUTHOR

Robin Redeker, "<elmex at ta-sa.org>"

BUGS

Please report any bugs or feature requests to "bug-bs-httpd at rt.cpan.org", or through the web interface at <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=AnyEvent-HTTPD>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc AnyEvent::HTTPD

You can also look for information at:

Git repository
<http://git.ta-sa.org/AnyEvent-HTTPD.git>
RT: CPAN's request tracker
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=AnyEvent-HTTPD>
AnnoCPAN: Annotated CPAN documentation
<http://annocpan.org/dist/AnyEvent-HTTPD>
CPAN Ratings
<http://cpanratings.perl.org/d/AnyEvent-HTTPD>
Search CPAN
<http://search.cpan.org/dist/AnyEvent-HTTPD>

ACKNOWLEDGEMENTS

   Andrey Smirnov   - for keep-alive patches.
   Pedro Melo       - for valuable input in general and patches.
   Nicholas Harteau - patch for ';' pair separator support,
                      patch for allowed_methods support
   Chris Kastorff   - patch for making default headers removable
                      and more fault tolerant w.r.t. case.
   Mons Anderson    - Optimizing the regexes in L<AnyEvent::HTTPD::HTTPConnection>
                      and adding the C<backlog> option to L<AnyEvent::HTTPD>.

COPYRIGHT & LICENSE

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.