Implement logout field.

Author: dadish

src/Field/Auth/LogoutField.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace ProcessWire\GraphQL\Field\Auth;
+
+use Youshido\GraphQL\Field\AbstractField;
+use Youshido\GraphQL\Config\Field\FieldConfig;
+use Youshido\GraphQL\Type\NonNullType;
+use Youshido\GraphQL\Execution\ResolveInfo;
+use ProcessWire\GraphQL\Type\Object\AuthResponseType;
+use ProcessWire\WireData;
+use ProcessWire\Session;
+
+class LogoutField extends AbstractField {
+
+  public function getType()
+  {
+    return new NonNullType(new AuthResponseType());
+  }
+
+  public function getName()
+  {
+    return 'logout';
+  }
+
+  public function getDescription()
+  {
+    return 'Allows you to logout from the app.';
+  }
+
+  public function resolve($value, array $args, ResolveInfo $info)
+  {
+    $session = \ProcessWire\wire('session');
+    $session = $session->logout();
+    $response = new WireData();
+    if ($session instanceof Session) {
+      $response->statusCode = 200;
+      $response->message = 'Successful logout!';
+    } else {
+      $response->statusCode = 500;
+      $response->message = 'Could not logout.';
+    }
+    return $response;
+  }
+
+}