AnyEvent::WebSocket::Client
WebSocket client for AnyEvent
SYNOPSIS
use AnyEvent::WebSocket::Client 0.12;
my $client = AnyEvent::WebSocket::Client->new;
$client->connect("ws://localhost:1234/service")->cb(sub {
# make $connection an our variable rather than
# my so that it will stick around. Once the
# connection falls out of scope any callbacks
# tied to it will be destroyed.
our $connection = eval { shift->recv };
if($@) {
# handle error...
warn $@;
return;
}
# send a message through the websocket...
$connection->send('a message');
# recieve message from the websocket...
$connection->on(each_message => sub {
# $connection is the same connection object
# $message isa AnyEvent::WebSocket::Message
my($connection, $message) = @_;
...
});
# handle a closed connection...
$connection->on(finish => sub {
# $connection is the same connection object
my($connection) = @_;
...
});
# close the connection (either inside or
# outside another callback)
$connection->close;
});
## uncomment to enter the event loop before exiting.
## Note that calling recv on a condition variable before
## it has been triggered does not work on all event loops
#AnyEvent->condvar->recv;
DESCRIPTION
This class provides an interface to interact with a web server that provides services via the WebSocket protocol in an AnyEvent context. It uses Protocol::WebSocket rather than reinventing the wheel. You could use AnyEvent and Protocol::WebSocket directly if you wanted finer grain control, but if that is not necessary then this class may save you some time.
The recommended API was added to the AnyEvent::WebSocket::Connection class with version 0.12, so it is recommended that you include that version when using this module. The older version of the API has since been deprecated and removed.
ATTRIBUTES
timeout
Timeout for the initial connection to the web server. The default is 30.
ssl_no_verify
If set to true, then secure WebSockets (those that use SSL/TLS) will not be verified. The default is false.
ssl_ca_file
Provide your own CA certificates file instead of using the system default for SSL/TLS verification.
protocol_version
The protocol version. See Protocol::WebSocket for the list of supported WebSocket protocol versions.
subprotocol
List of subprotocols to request from the server. This class will throw an exception if none of the protocols are supported by the server.
http_headers
Extra headers to include in the initial request. May be either specified as a hash reference, or an array reference. For example:
AnyEvent::WebSocket::Client->new(
http_headers => {
'X-Foo' => 'bar',
'X-Baz' => [ 'abc', 'def' ],
},
);
AnyEvent::WebSocket::Client->new(
http_headers => [
'X-Foo' => 'bar',
'X-Baz' => 'abc',
'X-Baz' => 'def',
],
);
Will generate:
X-Foo: bar
X-Baz: abc
X-Baz: def
Although, the order cannot be guaranteed when using the hash style.
max_payload_size
The maximum payload size for received frames. Currently defaults to whatever Protocol::WebSocket defaults to.
max_fragments
The maximum number of fragments for received frames. Currently defaults to whatever Protocol::WebSocket defaults to.
env_proxy
If you set true to this boolean attribute, it loads proxy settings
from environment variables. If it finds valid proxy settings,
connect
method will use that proxy.
Default: false.
For ws
WebSocket end-points, first it reads ws_proxy
(or
WS_PROXY
) environment variable. If it is not set or empty string,
then it reads http_proxy
(or HTTP_PROXY
). For wss
WebSocket
end-points, it reads wss_proxy
(WSS_PROXY
) and https_proxy
(HTTPS_PROXY
) environment variables.
METHODS
connect
my $cv = $client->connect($uri)
my $cv = $client->connect($uri, $host, $port);
Open a connection to the web server and open a WebSocket to the resource defined by the given URL. The URL may be either an instance of URI::ws, URI::wss, or a string that represents a legal WebSocket URL.
You can override the connection host and port by passing them in as the
second and third argument. These values (if provided) are passed directly
into AnyEvent::Socket's tcp_connect
function, so please note that
function's idiosyncrasies in the AnyEvent::Socket documentation. In
particular, you can pass in unix/
as the host and a filesystem path
as the "port" to connect to a unix domain socket.
This method will return an AnyEvent condition variable which you can
attach a callback to. The value sent through the condition variable will
be either an instance of AnyEvent::WebSocket::Connection or a croak
message indicating a failure. The synopsis above shows how to catch
such errors using eval
.
FAQ
My program exits before doing anything, what is up with that?
See this FAQ from AnyEvent: AnyEvent::FAQ#My-program-exits-before-doing-anything-whats-going-on.
It is probably also a good idea to review the AnyEvent documentation if you are new to AnyEvent or event-based programming.
My callbacks aren't being called!
Make sure that the connection object is still in scope. This often happens
if you use a my $connection
variable and don't save it somewhere. For
example:
$client->connect("ws://foo/service")->cb(sub {
my $connection = eval { shift->recv };
if($@)
{
warn $@;
return;
}
...
});
Unless $connection
is saved somewhere it will get deallocated along with
any associated message callbacks will also get deallocated once the connect
callback is executed. One way to make sure that the connection doesn't
get deallocated is to make it a our
variable (as in the synopsis above)
instead.
CAVEATS
This is pretty simple minded and there are probably WebSocket features that you might like to use that aren't supported by this distribution. Patches are encouraged to improve it.
SEE ALSO
- AnyEvent::WebSocket::Connection
- AnyEvent::WebSocket::Message
- AnyEvent::WebSocket::Server
- AnyEvent
- URI::ws
- URI::wss
- Protocol::WebSocket
- Net::WebSocket::Server
- Net::Async::WebSocket
- RFC 6455 The WebSocket Protocol
AUTHOR
Author: Graham Ollis plicease@cpan.org
Contributors:
Toshio Ito (debug-ito, TOSHIOITO)
José Joaquín Atria (JJATRIA)
Kivanc Yazan (KYZN)
Yanick Champoux (YANICK)
Fayland Lam (FAYLAND)
Daniel Kamil Kozar (xavery)
COPYRIGHT AND LICENSE
This software is copyright (c) 2013-2022 by Graham Ollis.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.