Broadcaster.php

TLDR

This file defines an abstract class Broadcaster that implements the BroadcasterContract interface. It provides common methods and properties that can be used by different broadcasting broadcasters. The class has methods for resolving the authenticated user, registering channel authenticators, and authenticating incoming requests for specific channels. It also has helper methods for extracting parameters, resolving bindings, and formatting channel arrays. The class also has methods for retrieving the authenticated user and channel options.

Methods

resolveAuthenticatedUser($request)

This method resolves the authenticated user payload for the incoming connection request. It accepts an instance of Illuminate\Http\Request and returns an array or null.

resolveAuthenticatedUserUsing($callback)

This method registers the user retrieval callback used to authenticate connections. It accepts a closure callback.

channel($channel, $callback, $options = [])

This method registers a channel authenticator. It accepts a channel instance or class, a callback or class name, and an array of options. It returns an instance of the broadcaster.

verifyUserCanAccessChannel($request, $channel)

This method authenticates the incoming request for a given channel. It accepts an instance of Illuminate\Http\Request and a string representing the channel. It throws an AccessDeniedHttpException exception if the user does not have access to the channel.

getChannels()

This method returns a collection of all registered channels.

END

<?php

namespace Illuminate\Broadcasting\Broadcasters;

use Closure;
use Exception;
use Illuminate\Container\Container;
use Illuminate\Contracts\Broadcasting\Broadcaster as BroadcasterContract;
use Illuminate\Contracts\Broadcasting\HasBroadcastChannel;
use Illuminate\Contracts\Routing\BindingRegistrar;
use Illuminate\Contracts\Routing\UrlRoutable;
use Illuminate\Support\Arr;
use Illuminate\Support\Reflector;
use ReflectionClass;
use ReflectionFunction;
use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;

abstract class Broadcaster implements BroadcasterContract
{
    /**
     * The callback to resolve the authenticated user information.
     *
     * @var \Closure|null
     */
    protected $authenticatedUserCallback = null;

    /**
     * The registered channel authenticators.
     *
     * @var array
     */
    protected $channels = [];

    /**
     * The registered channel options.
     *
     * @var array
     */
    protected $channelOptions = [];

    /**
     * The binding registrar instance.
     *
     * @var \Illuminate\Contracts\Routing\BindingRegistrar
     */
    protected $bindingRegistrar;

    /**
     * Resolve the authenticated user payload for the incoming connection request.
     *
     * See: https://pusher.com/docs/channels/library_auth_reference/auth-signatures/#user-authentication.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return array|null
     */
    public function resolveAuthenticatedUser($request)
    {
        if ($this->authenticatedUserCallback) {
            return $this->authenticatedUserCallback->__invoke($request);
        }
    }

    /**
     * Register the user retrieval callback used to authenticate connections.
     *
     * See: https://pusher.com/docs/channels/library_auth_reference/auth-signatures/#user-authentication.
     *
     * @param  \Closure  $callback
     * @return void
     */
    public function resolveAuthenticatedUserUsing(Closure $callback)
    {
        $this->authenticatedUserCallback = $callback;
    }

    /**
     * Register a channel authenticator.
     *
     * @param  \Illuminate\Contracts\Broadcasting\HasBroadcastChannel|string  $channel
     * @param  callable|string  $callback
     * @param  array  $options
     * @return $this
     */
    public function channel($channel, $callback, $options = [])
    {
        if ($channel instanceof HasBroadcastChannel) {
            $channel = $channel->broadcastChannelRoute();
        } elseif (is_string($channel) && class_exists($channel) && is_a($channel, HasBroadcastChannel::class, true)) {
            $channel = (new $channel)->broadcastChannelRoute();
        }

        $this->channels[$channel] = $callback;

        $this->channelOptions[$channel] = $options;

        return $this;
    }

    /**
     * Authenticate the incoming request for a given channel.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  string  $channel
     * @return mixed
     *
     * @throws \Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException
     */
    protected function verifyUserCanAccessChannel($request, $channel)
    {
        foreach ($this->channels as $pattern => $callback) {
            if (! $this->channelNameMatchesPattern($channel, $pattern)) {
                continue;
            }

            $parameters = $this->extractAuthParameters($pattern, $channel, $callback);

            $handler = $this->normalizeChannelHandlerToCallable($callback);

            $result = $handler($this->retrieveUser($request, $channel), ...$parameters);

            if ($result === false) {
                throw new AccessDeniedHttpException;
            } elseif ($result) {
                return $this->validAuthenticationResponse($request, $result);
            }
        }

        throw new AccessDeniedHttpException;
    }

    /**
     * Extract the parameters from the given pattern and channel.
     *
     * @param  string  $pattern
     * @param  string  $channel
     * @param  callable|string  $callback
     * @return array
     */
    protected function extractAuthParameters($pattern, $channel, $callback)
    {
        $callbackParameters = $this->extractParameters($callback);

        return collect($this->extractChannelKeys($pattern, $channel))->reject(function ($value, $key) {
            return is_numeric($key);
        })->map(function ($value, $key) use ($callbackParameters) {
            return $this->resolveBinding($key, $value, $callbackParameters);
        })->values()->all();
    }

    /**
     * Extracts the parameters out of what the user passed to handle the channel authentication.
     *
     * @param  callable|string  $callback
     * @return \ReflectionParameter[]
     *
     * @throws \Exception
     */
    protected function extractParameters($callback)
    {
        if (is_callable($callback)) {
            return (new ReflectionFunction($callback))->getParameters();
        } elseif (is_string($callback)) {
            return $this->extractParametersFromClass($callback);
        }

        throw new Exception('Given channel handler is an unknown type.');
    }

    /**
     * Extracts the parameters out of a class channel's "join" method.
     *
     * @param  string  $callback
     * @return \ReflectionParameter[]
     *
     * @throws \Exception
     */
    protected function extractParametersFromClass($callback)
    {
        $reflection = new ReflectionClass($callback);

        if (! $reflection->hasMethod('join')) {
            throw new Exception('Class based channel must define a "join" method.');
        }

        return $reflection->getMethod('join')->getParameters();
    }

    /**
     * Extract the channel keys from the incoming channel name.
     *
     * @param  string  $pattern
     * @param  string  $channel
     * @return array
     */
    protected function extractChannelKeys($pattern, $channel)
    {
        preg_match('/^'.preg_replace('/\{(.*?)\}/', '(?<$1>[^\.]+)', $pattern).'/', $channel, $keys);

        return $keys;
    }

    /**
     * Resolve the given parameter binding.
     *
     * @param  string  $key
     * @param  string  $value
     * @param  array  $callbackParameters
     * @return mixed
     */
    protected function resolveBinding($key, $value, $callbackParameters)
    {
        $newValue = $this->resolveExplicitBindingIfPossible($key, $value);

        return $newValue === $value ? $this->resolveImplicitBindingIfPossible(
            $key, $value, $callbackParameters
        ) : $newValue;
    }

    /**
     * Resolve an explicit parameter binding if applicable.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return mixed
     */
    protected function resolveExplicitBindingIfPossible($key, $value)
    {
        $binder = $this->binder();

        if ($binder && $binder->getBindingCallback($key)) {
            return call_user_func($binder->getBindingCallback($key), $value);
        }

        return $value;
    }

    /**
     * Resolve an implicit parameter binding if applicable.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @param  array  $callbackParameters
     * @return mixed
     *
     * @throws \Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException
     */
    protected function resolveImplicitBindingIfPossible($key, $value, $callbackParameters)
    {
        foreach ($callbackParameters as $parameter) {
            if (! $this->isImplicitlyBindable($key, $parameter)) {
                continue;
            }

            $className = Reflector::getParameterClassName($parameter);

            if (is_null($model = (new $className)->resolveRouteBinding($value))) {
                throw new AccessDeniedHttpException;
            }

            return $model;
        }

        return $value;
    }

    /**
     * Determine if a given key and parameter is implicitly bindable.
     *
     * @param  string  $key
     * @param  \ReflectionParameter  $parameter
     * @return bool
     */
    protected function isImplicitlyBindable($key, $parameter)
    {
        return $parameter->getName() === $key &&
                        Reflector::isParameterSubclassOf($parameter, UrlRoutable::class);
    }

    /**
     * Format the channel array into an array of strings.
     *
     * @param  array  $channels
     * @return array
     */
    protected function formatChannels(array $channels)
    {
        return array_map(function ($channel) {
            return (string) $channel;
        }, $channels);
    }

    /**
     * Get the model binding registrar instance.
     *
     * @return \Illuminate\Contracts\Routing\BindingRegistrar
     */
    protected function binder()
    {
        if (! $this->bindingRegistrar) {
            $this->bindingRegistrar = Container::getInstance()->bound(BindingRegistrar::class)
                        ? Container::getInstance()->make(BindingRegistrar::class) : null;
        }

        return $this->bindingRegistrar;
    }

    /**
     * Normalize the given callback into a callable.
     *
     * @param  mixed  $callback
     * @return callable
     */
    protected function normalizeChannelHandlerToCallable($callback)
    {
        return is_callable($callback) ? $callback : function (...$args) use ($callback) {
            return Container::getInstance()
                ->make($callback)
                ->join(...$args);
        };
    }

    /**
     * Retrieve the authenticated user using the configured guard (if any).
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  string  $channel
     * @return mixed
     */
    protected function retrieveUser($request, $channel)
    {
        $options = $this->retrieveChannelOptions($channel);

        $guards = $options['guards'] ?? null;

        if (is_null($guards)) {
            return $request->user();
        }

        foreach (Arr::wrap($guards) as $guard) {
            if ($user = $request->user($guard)) {
                return $user;
            }
        }
    }

    /**
     * Retrieve options for a certain channel.
     *
     * @param  string  $channel
     * @return array
     */
    protected function retrieveChannelOptions($channel)
    {
        foreach ($this->channelOptions as $pattern => $options) {
            if (! $this->channelNameMatchesPattern($channel, $pattern)) {
                continue;
            }

            return $options;
        }

        return [];
    }

    /**
     * Check if the channel name from the request matches a pattern from registered channels.
     *
     * @param  string  $channel
     * @param  string  $pattern
     * @return bool
     */
    protected function channelNameMatchesPattern($channel, $pattern)
    {
        return preg_match('/^'.preg_replace('/\{(.*?)\}/', '([^\.]+)', $pattern).'$/', $channel);
    }

    /**
     * Get all of the registered channels.
     *
     * @return \Illuminate\Support\Collection
     */
    public function getChannels()
    {
        return collect($this->channels);
    }
}