laravel-websockets/src/Channels/PresenceChannel.php

<?php

namespace BeyondCode\LaravelWebSockets\Channels;

use BeyondCode\LaravelWebSockets\DashboardLogger;
use BeyondCode\LaravelWebSockets\Server\Exceptions\InvalidSignature;
use Ratchet\ConnectionInterface;
use stdClass;

class PresenceChannel extends PrivateChannel
{
    /**
     * Subscribe to the channel.
     *
     * @see    https://pusher.com/docs/pusher_protocol#presence-channel-events
     * @param  \Ratchet\ConnectionInterface  $connection
     * @param  \stdClass  $payload
     * @return void
     * @throws InvalidSignature
     */
    public function subscribe(ConnectionInterface $connection, stdClass $payload)
    {
        $this->verifySignature($connection, $payload);

        $this->saveConnection($connection);

        $this->channelManager->userJoinedPresenceChannel(
            $connection,
            $user = json_decode($payload->channel_data),
            $this->getName(),
            $payload
        );

        $this->channelManager
            ->getChannelMembers($connection->app->id, $this->getName())
            ->then(function ($users) use ($connection) {
                $hash = [];

                foreach ($users as $socketId => $user) {
                    $hash[$user->user_id] = $user->user_info ?? [];
                }

                $connection->send(json_encode([
                    'event' => 'pusher_internal:subscription_succeeded',
                    'channel' => $this->getName(),
                    'data' => json_encode([
                        'presence' => [
                            'ids' => collect($users)->map(function ($user) {
                                return (string) $user->user_id;
                            })->values(),
                            'hash' => $hash,
                            'count' => count($users),
                        ],
                    ]),
                ]));
            });

        // The `pusher_internal:member_added` event is triggered when a user joins a channel.
        // It's quite possible that a user can have multiple connections to the same channel
        // (for example by having multiple browser tabs open)
        // and in this case the events will only be triggered when the first tab is opened.
        $this->channelManager
            ->getMemberSockets($user->user_id, $connection->app->id, $this->getName())
            ->then(function ($sockets) use ($payload, $connection) {
                if (count($sockets) === 1) {
                    $memberAddedPayload = [
                        'event' => 'pusher_internal:member_added',
                        'channel' => $this->getName(),
                        'data' => $payload->channel_data,
                    ];

                    $this->broadcastToEveryoneExcept(
                        (object) $memberAddedPayload, $connection->socketId,
                        $connection->app->id
                    );
                }
            });

        DashboardLogger::log($connection->app->id, DashboardLogger::TYPE_SUBSCRIBED, [
            'socketId' => $connection->socketId,
            'channel' => $this->getName(),
            'multi-device' => isset($connection->duplicate),
        ]);
    }

    /**
     * Unsubscribe connection from the channel.
     *
     * @param  \Ratchet\ConnectionInterface  $connection
     * @return void
     */
    public function unsubscribe(ConnectionInterface $connection)
    {
        parent::unsubscribe($connection);

        $this->channelManager
            ->getChannelMember($connection, $this->getName())
            ->then(function ($user) use ($connection) {
                $user = @json_decode($user);

                if (! $user) {
                    return;
                }

                $this->channelManager->userLeftPresenceChannel(
                    $connection, $user, $this->getName()
                );

                // The `pusher_internal:member_removed` is triggered when a user leaves a channel.
                // It's quite possible that a user can have multiple connections to the same channel
                // (for example by having multiple browser tabs open)
                // and in this case the events will only be triggered when the last one is closed.
                $this->channelManager
                    ->getMemberSockets($user->user_id, $connection->app->id, $this->getName())
                    ->then(function ($sockets) use ($connection, $user) {
                        if (count($sockets) === 0) {
                            $memberRemovedPayload = [
                                'event' => 'pusher_internal:member_removed',
                                'channel' => $this->getName(),
                                'data' => json_encode([
                                    'user_id' => $user->user_id,
                                ]),
                            ];

                            $this->broadcastToEveryoneExcept(
                                (object) $memberRemovedPayload, $connection->socketId,
                                $connection->app->id
                            );
                        }
                     });
            });
    }
}