Added a check to make sure the server doesn't exist before creating it

public/css/wyrm.css

@@ -2,6 +2,18 @@ body{
   background-color: #e6e6e6;
 }
 
+input[type=submit]:disabled,
+button:disabled{
+  background-color: darkgrey;
+}
+input[type=submit]:disabled:hover,
+button:disabled:hover{
+  background-color: darkgrey;
+  border: 1px solid #bbb;
+  color: #555;
+  cursor: not-allowed;
+}
+
 /* set the max-width for centered content */
 .container{
   max-width: 1100px;

public/js/drake.js

@@ -1,7 +1,11 @@
 $(document).ready(function () {
+  // periodically check for server status updates
   $('.serverItem').each(function() {
     setInterval(updateServer, 5000, $(this));
   });
+
+  // set the serverName input field to check if the server exists
+  $('input#serverName').on('change', checkServerExists);
 });
 
 function updateServer(elem) {
@@ -10,3 +14,16 @@ function updateServer(elem) {
     elem.children('.serverState').eq(0).text(data.state);
   });
 }
+
+function checkServerExists() {
+  $.get('/server/' + $(this).val() + '/status', function(data, state) {
+    if (data.exists) {
+      $('input#createSubmit').prop('disabled', true);
+      alert('That server name is already used; please use another name!');
+    } else {
+      if ($('input#createSubmit').prop('disabled')) {
+        $('input#createSubmit').prop('disabled', false);
+      }
+    }
+  });
+}

src/routes.php

@@ -73,9 +73,17 @@ $app->get('/server/{serverName}/status', function (Request $request, Response $r
   $config = $this->get('config');
   $serverDir = join('/', array($config->get('server_directory'), $args['serverName']));
 
+  // check if the server exists - if not, return a false result
+  if (!is_dir($serverDir)) {
+    $response->getBody()->write(json_encode(array('exists' => false)));
+    return $response
+      ->withHeader('Content-Type', 'application/json');
+  }
+
   // create server object and pass info back to client as JSON data
   $server = new Server($serverDir);
   $serverData = [
+    'exists'  => true,
     'name'    => $server->getName(),
     'version' => $server->getVersion(),
     'state'   => $server->getState() ? 'Running' : 'Stopped',

views/create.twig

@@ -16,16 +16,16 @@
       <div class="row">
         <div class="columns six">
           <label for="serverName">Server name:</label>
-          <input id="serverName" name="serverName" class="u-full-width" type="text" placeholder="MyServer">
+          <input id="serverName" name="serverName" class="u-full-width" type="text" placeholder="MyServer" required>
         </div>
 
         <div class="columns six">
           <label for="serverVersion">Minecraft version:</label>
-          <input id="serverVersion" name="serverVersion" class="u-full-width" type="text" placeholder="1.19.2">
+          <input id="serverVersion" name="serverVersion" class="u-full-width" type="text" placeholder="1.19.2" required>
         </div>
       </div>
 
-      <input type="submit" value="Submit">
+      <input id="createSubmit" type="submit" value="Submit">
     </form>
   </div>
 </section>