NAME

AnyEvent::HTTP - simple but non-blocking HTTP/HTTPS client

SYNOPSIS

   use AnyEvent::HTTP;

   http_get "http://www.nethype.de/", sub { print $_[1] };

   # ... do something else here

DESCRIPTION

This module is an AnyEvent user, you need to make sure that you use and run a supported event loop.

This module implements a simple, stateless and non-blocking HTTP client. It supports GET, POST and other request methods, cookies and more, all on a very low level. It can follow redirects supports proxies and automatically limits the number of connections to the values specified in the RFC.

It should generally be a "good client" that is enough for most HTTP tasks. Simple tasks should be simple, but complex tasks should still be possible as the user retains control over request and response headers.

The caller is responsible for authentication management, cookies (if the simplistic implementation in this module doesn't suffice), referer and other high-level protocol details for which this module offers only limited support.

METHODS

http_get $url, key => value..., $cb->($data, $headers)

Executes an HTTP-GET request. See the http_request function for details on additional parameters.

http_head $url, key => value..., $cb->($data, $headers)

Executes an HTTP-HEAD request. See the http_request function for details on additional parameters.

http_post $url, $body, key => value..., $cb->($data, $headers)

Executes an HTTP-POST request with a request body of $bod. See the http_request function for details on additional parameters.

http_request $method => $url, key => value..., $cb->($data, $headers)

Executes a HTTP request of type $method (e.g. GET, POST). The URL must be an absolute http or https URL.

The callback will be called with the response data as first argument (or undef if it wasn't available due to errors), and a hash-ref with response headers as second argument.

All the headers in that hash are lowercased. In addition to the response headers, the "pseudo-headers" HTTPVersion, Status and Reason contain the three parts of the HTTP Status-Line of the same name. The pseudo-header URL contains the original URL (which can differ from the requested URL when following redirects).

If the server sends a header multiple lines, then their contents will be joined together with \x00.

If an internal error occurs, such as not being able to resolve a hostname, then $data will be undef, $headers->{Status} will be 599 and the Reason pseudo-header will contain an error message.

A typical callback might look like this:

   sub {
      my ($body, $hdr) = @_;

      if ($hdr->{Status} =~ /^2/) {
         ... everything should be ok
      } else {
         print "error, $hdr->{Status} $hdr->{Reason}\n";
      }
   }

Additional parameters are key-value pairs, and are fully optional. They include:

recurse => $count (default: $MAX_RECURSE)

Whether to recurse requests or not, e.g. on redirects, authentication retries and so on, and how often to do so.

headers => hashref

The request headers to use. Currently, http_request may provide its own Host:, Content-Length:, Connection: and Cookie: headers and will provide defaults for User-Agent: and Referer:.

timeout => $seconds

The time-out to use for various stages - each connect attempt will reset the timeout, as will read or write activity. Default timeout is 5 minutes.

proxy => [$host, $port[, $scheme]] or undef

Use the given http proxy for all requests. If not specified, then the default proxy (as specified by $ENV{http_proxy}) is used.

$scheme must be either missing or http for HTTP, or https for HTTPS.

body => $string

The request body, usually empty. Will be-sent as-is (future versions of this module might offer more options).

cookie_jar => $hash_ref

Passing this parameter enables (simplified) cookie-processing, loosely based on the original netscape specification.

The $hash_ref must be an (initially empty) hash reference which will get updated automatically. It is possible to save the cookie_jar to persistent storage with something like JSON or Storable, but this is not recommended, as expire times are currently being ignored.

Note that this cookie implementation is not of very high quality, nor meant to be complete. If you want complete cookie management you have to do that on your own. cookie_jar is meant as a quick fix to get some cookie-using sites working. Cookies are a privacy disaster, do not use them unless required to.

Example: make a simple HTTP GET request for http://www.nethype.de/

   http_request GET => "http://www.nethype.de/", sub {
      my ($body, $hdr) = @_;
      print "$body\n";
   };

Example: make a HTTP HEAD request on https://www.google.com/, use a timeout of 30 seconds.

   http_request
      GET     => "https://www.google.com",
      timeout => 30,
      sub {
         my ($body, $hdr) = @_;
         use Data::Dumper;
         print Dumper $hdr;
      }
   ;

GLOBAL FUNCTIONS AND VARIABLES

AnyEvent::HTTP::set_proxy "proxy-url"

Sets the default proxy server to use. The proxy-url must begin with a string of the form http://host:port (optionally https:...).

$AnyEvent::HTTP::MAX_RECURSE

The default value for the recurse request parameter (default: 10).

$AnyEvent::HTTP::USERAGENT

The default value for the User-Agent header (the default is Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; +http://software.schmorp.de/pkg/AnyEvent)).

$AnyEvent::HTTP::MAX_PERSISTENT

The maximum number of persistent connections to keep open (default: 8).

Not implemented currently.

$AnyEvent::HTTP::PERSISTENT_TIMEOUT

The maximum time to cache a persistent connection, in seconds (default: 2).

Not implemented currently.

$AnyEvent::HTTP::ACTIVE

The number of active connections. This is not the number of currently running requests, but the number of currently open and non-idle TCP connections. This number of can be useful for load-leveling.

SEE ALSO

AnyEvent.

AUTHOR

   Marc Lehmann <schmorp@schmorp.de>
   http://home.schmorp.de/