Added the ability to retrieve welcome messags from APIs

app/Server/Http/Controllers/ControlMessageController.php

@@ -12,6 +12,7 @@ use App\Server\Exceptions\NoFreePortAvailable;
 use Illuminate\Support\Arr;
 use Ratchet\ConnectionInterface;
 use Ratchet\WebSocket\MessageComponentInterface;
+use React\EventLoop\LoopInterface;
 use React\Promise\Deferred;
 use React\Promise\PromiseInterface;
 use function React\Promise\reject;
@@ -150,6 +151,24 @@ class ControlMessageController implements MessageComponentInterface
             });
     }
 
+    protected function resolveConnectionMessage($connectionInfo, $user) {
+        $deferred = new Deferred();
+
+        $connectionMessageResolver = config('expose.admin.messages.resolve_connection_message')($connectionInfo, $user);
+
+        if ($connectionMessageResolver instanceof PromiseInterface) {
+            $connectionMessageResolver->then(function ($connectionMessage) use ($connectionInfo, $deferred) {
+                $connectionInfo->message = $connectionMessage;
+                $deferred->resolve($connectionInfo);
+            });
+        } else {
+            $connectionInfo->message = $connectionMessageResolver;
+            return \React\Promise\resolve($connectionInfo);
+        }
+
+        return $deferred->promise();
+    }
+
     protected function handleHttpConnection(ConnectionInterface $connection, $data, $user = null)
     {
         $this->hasValidDomain($connection, $data->server_host, $user)
@@ -167,10 +186,13 @@ class ControlMessageController implements MessageComponentInterface
 
                 $this->connectionManager->limitConnectionLength($connectionInfo, config('expose.admin.maximum_connection_length'));
 
+                return $this->resolveConnectionMessage($connectionInfo, $user);
+            })
+            ->then(function ($connectionInfo) use ($data, $connection, $user) {
                 $connection->send(json_encode([
                     'event' => 'authenticated',
                     'data' => [
-                        'message' => config('expose.admin.messages.resolve_connection_message')($connectionInfo, $user),
+                        'message' => $connectionInfo->message,
                         'subdomain' => $connectionInfo->subdomain,
                         'server_host' => $connectionInfo->serverHost,
                         'user' => $user,

app/Server/Support/RetrieveWelcomeMessageFromApi.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace App\Server\Support;
+
+use Exception;
+use Psr\Http\Message\ResponseInterface;
+use Clue\React\Buzz\Browser;
+
+class RetrieveWelcomeMessageFromApi
+{
+    /** @var Browser */
+    protected $browser;
+
+    /** @var string */
+    protected $url;
+
+    public function __construct(Browser $browser)
+    {
+        $this->browser = $browser;
+
+        $this->url = config('expose.admin.welcome_message_api_url');
+    }
+
+    public function forUser($user)
+    {
+        return $this->browser
+            ->get($this->url . '?' . http_build_query($user), [
+                'Accept' => 'application/json',
+            ])
+            ->then(function (ResponseInterface $response) {
+                $result = json_decode($response->getBody());
+
+                return $result->message ?? '';
+            }, function (Exception $e) {
+                return '';
+            });
+    }
+}