feature request websocketconnections :PluginKeyword

[hypericum]

Hi Yanik,

thank you very much for your great Dancer2::Plugin::WebSocket!

I have one little question that I haven't found an answer yet:

How do I send a new WebSocket Message from a Dancer Server through one of the open Sockets to a Client? (not in direct-reply to an incoming message from the client e.g. on_message or something similar)

The documented part (on_message,...) works well, connections are held open and can be found inside the Dancer2::Plugin::WebSocket object.

I'm missing something like:

has websocketconnections :PluginKeyword => (
    is => 'ro',
    default => sub{ {} },
);

instead of just:

has connections => (
    is => 'ro',
    default => sub{ {} },
);

or at least:

Dancer2::Plugin::WebSocket->connections->{$MyClientWebSocketConnectionID}->send($Message);

The shortest way I've found to send a message through an active websocket connection outside the main .pm was:

my $WebSocketConnection = (grep { (ref $_ ) eq 'Dancer2::Plugin::WebSocket' }  @{ app->plugins })[0];

$WebSocketConnection->connections->{ $MyClientWebSocketConnectionID }->send($Message);

If you know a better way please enlight my humble mind :)

Thank you,
Johannes

[yanick]

On 2019-07-15 01:39 PM, hypericum wrote:

thank you very much for your great Dancer2::Plugin::WebSocket!

You're very welcome. ^.^

I have one little question that I haven't found an answer yet:

How do I send a new WebSocket Message from a Dancer Server through one of the open Sockets to a Client? (not in direct-reply to an incoming message from the client e.g. on_message or something similar)

You are right. I should make this easier via a keyword. In the meantime, you could do

package MyApp;

use Dancer2;
use Dancer2::Plugin::WebSocket;

my @connections;

websocket_on_open sub {
  my( $conn ) = @_;
  push @connections, $conn;
};

get '/' => sub {
  my $ws_url = websocket_url;
  return $ws_url;
};

get '/greet' => sub {
    # TODO take care of closed connections
    $_->send( "Hi there!" ) for @connections;
    return "done";
};

1;

I'll try to add the new keyword later on today. Hang tight! :-)

[hypericum]

this works well as long as I'm in the same scope of MyApp...

If I'm correct in

package MyApp::Foo::Bar:FooBar

@connections wouldn't be available any more.

I've solved it by putting the $Conn->id into the config like:

config->{websocketconnections}->{ $ClientName } = {
    ID         => $Conn->id,
};

in MyApp::Foo::Bar:FooBar sending a message works like that:

my $WebSocketConnection = (grep { (ref $_ ) eq 'Dancer2::Plugin::WebSocket' }  @{ app->plugins })[0];


$WebSocketConnection->connections->{ 
    config->{websocketconnections}->{ $ClientName }->{ID} 
}->send($Message);

...so the main point would be to access @connections from Dancer Packages deeper down in the application, a

use Dancer2::Plugin::WebSocket;

wouldn't be the problem in MyApp::Foo::Bar:FooBar, important would be that the same module-variable @connections would be presented. ;)

THX a lot for your perspective "I'll try to add the new keyword later " ^^

[yanick]

If I'm correct in

package MyApp::Foo::Bar:FooBar
@connections wouldn't be available any more.

Yes, true. But if you want to access it from elsewhere, switch the my for a our and you'll be able to access it anywhere at all via @MyApp::connections.

[yanick]

This being said, the new keyword websocket_connections is available in the release that I just punted to cpan. :-)