Use ::class instead of some hardcoded class names

This gives us better refactoring functionality in IDEs like
PhpStorm, and also more quickly surfaces typos through errors
about undefined classes. :)

src/Api/Controller/CreateDiscussionController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\DiscussionSerializer;
 use Flarum\Discussion\Command\ReadDiscussion;
 use Flarum\Discussion\Command\StartDiscussion;
 use Flarum\Post\Floodgate;
@@ -23,7 +24,7 @@ class CreateDiscussionController extends AbstractCreateController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\DiscussionSerializer';
+    public $serializer = DiscussionSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/CreateGroupController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\GroupSerializer;
 use Flarum\Group\Command\CreateGroup;
 use Illuminate\Contracts\Bus\Dispatcher;
 use Psr\Http\Message\ServerRequestInterface;
@@ -21,7 +22,7 @@ class CreateGroupController extends AbstractCreateController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\GroupSerializer';
+    public $serializer = GroupSerializer::class;
 
     /**
      * @var Dispatcher

src/Api/Controller/CreatePostController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\PostSerializer;
 use Flarum\Discussion\Command\ReadDiscussion;
 use Flarum\Post\Command\PostReply;
 use Flarum\Post\Floodgate;
@@ -23,7 +24,7 @@ class CreatePostController extends AbstractCreateController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\PostSerializer';
+    public $serializer = PostSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/CreateUserController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\CurrentUserSerializer;
 use Flarum\User\Command\RegisterUser;
 use Illuminate\Contracts\Bus\Dispatcher;
 use Psr\Http\Message\ServerRequestInterface;
@@ -21,7 +22,7 @@ class CreateUserController extends AbstractCreateController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\CurrentUserSerializer';
+    public $serializer = CurrentUserSerializer::class;
 
     /**
      * @var Dispatcher

src/Api/Controller/DeleteAvatarController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\UserSerializer;
 use Flarum\User\Command\DeleteAvatar;
 use Illuminate\Contracts\Bus\Dispatcher;
 use Psr\Http\Message\ServerRequestInterface;
@@ -21,7 +22,7 @@ class DeleteAvatarController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\UserSerializer';
+    public $serializer = UserSerializer::class;
 
     /**
      * @var Dispatcher

src/Api/Controller/ListDiscussionsController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\DiscussionSerializer;
 use Flarum\Discussion\Search\DiscussionSearcher;
 use Flarum\Http\UrlGenerator;
 use Flarum\Search\SearchCriteria;
@@ -22,7 +23,7 @@ class ListDiscussionsController extends AbstractListController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\DiscussionSerializer';
+    public $serializer = DiscussionSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/ListGroupsController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\GroupSerializer;
 use Flarum\Group\Group;
 use Psr\Http\Message\ServerRequestInterface;
 use Tobscure\JsonApi\Document;
@@ -20,7 +21,7 @@ class ListGroupsController extends AbstractListController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\GroupSerializer';
+    public $serializer = GroupSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/ListNotificationsController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\NotificationSerializer;
 use Flarum\Discussion\Discussion;
 use Flarum\Http\UrlGenerator;
 use Flarum\Notification\NotificationRepository;
@@ -23,7 +24,7 @@ class ListNotificationsController extends AbstractListController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\NotificationSerializer';
+    public $serializer = NotificationSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/ListPostsController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\PostSerializer;
 use Flarum\Event\ConfigurePostsQuery;
 use Flarum\Post\PostRepository;
 use Illuminate\Database\Eloquent\Builder;
@@ -23,7 +24,7 @@ class ListPostsController extends AbstractListController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\PostSerializer';
+    public $serializer = PostSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/ListUsersController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\UserSerializer;
 use Flarum\Http\UrlGenerator;
 use Flarum\Search\SearchCriteria;
 use Flarum\User\Exception\PermissionDeniedException;
@@ -23,7 +24,7 @@ class ListUsersController extends AbstractListController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\UserSerializer';
+    public $serializer = UserSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/ShowDiscussionController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\DiscussionSerializer;
 use Flarum\Discussion\Discussion;
 use Flarum\Discussion\DiscussionRepository;
 use Flarum\Post\PostRepository;
@@ -33,7 +34,7 @@ class ShowDiscussionController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\DiscussionSerializer';
+    public $serializer = DiscussionSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/ShowForumController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\ForumSerializer;
 use Flarum\Group\Group;
 use Psr\Http\Message\ServerRequestInterface;
 use Tobscure\JsonApi\Document;
@@ -20,7 +21,7 @@ class ShowForumController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\ForumSerializer';
+    public $serializer = ForumSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/ShowPostController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\PostSerializer;
 use Flarum\Post\PostRepository;
 use Psr\Http\Message\ServerRequestInterface;
 use Tobscure\JsonApi\Document;
@@ -20,7 +21,7 @@ class ShowPostController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\PostSerializer';
+    public $serializer = PostSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/ShowUserController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\UserSerializer;
 use Flarum\User\UserRepository;
 use Psr\Http\Message\ServerRequestInterface;
 use Tobscure\JsonApi\Document;
@@ -20,7 +21,7 @@ class ShowUserController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\UserSerializer';
+    public $serializer = UserSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/UpdateDiscussionController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\DiscussionSerializer;
 use Flarum\Discussion\Command\EditDiscussion;
 use Flarum\Discussion\Command\ReadDiscussion;
 use Illuminate\Contracts\Bus\Dispatcher;
@@ -23,7 +24,7 @@ class UpdateDiscussionController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\DiscussionSerializer';
+    public $serializer = DiscussionSerializer::class;
 
     /**
      * @var Dispatcher

src/Api/Controller/UpdateGroupController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\GroupSerializer;
 use Flarum\Group\Command\EditGroup;
 use Illuminate\Contracts\Bus\Dispatcher;
 use Psr\Http\Message\ServerRequestInterface;
@@ -21,7 +22,7 @@ class UpdateGroupController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\GroupSerializer';
+    public $serializer = GroupSerializer::class;
 
     /**
      * @var Dispatcher

src/Api/Controller/UpdateNotificationController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\NotificationSerializer;
 use Flarum\Notification\Command\ReadNotification;
 use Illuminate\Contracts\Bus\Dispatcher;
 use Psr\Http\Message\ServerRequestInterface;
@@ -21,7 +22,7 @@ class UpdateNotificationController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\NotificationSerializer';
+    public $serializer = NotificationSerializer::class;
 
     /**
      * @var Dispatcher

src/Api/Controller/UpdatePostController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\PostSerializer;
 use Flarum\Post\Command\EditPost;
 use Illuminate\Contracts\Bus\Dispatcher;
 use Psr\Http\Message\ServerRequestInterface;
@@ -21,7 +22,7 @@ class UpdatePostController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\PostSerializer';
+    public $serializer = PostSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/UpdateUserController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\CurrentUserSerializer;
 use Flarum\User\Command\EditUser;
 use Flarum\User\Exception\PermissionDeniedException;
 use Illuminate\Contracts\Bus\Dispatcher;
@@ -22,7 +23,7 @@ class UpdateUserController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\CurrentUserSerializer';
+    public $serializer = CurrentUserSerializer::class;
 
     /**
      * {@inheritdoc}

src/Api/Controller/UploadAvatarController.php

@@ -11,6 +11,7 @@
 
 namespace Flarum\Api\Controller;
 
+use Flarum\Api\Serializer\UserSerializer;
 use Flarum\User\Command\UploadAvatar;
 use Illuminate\Contracts\Bus\Dispatcher;
 use Psr\Http\Message\ServerRequestInterface;
@@ -21,7 +22,7 @@ class UploadAvatarController extends AbstractShowController
     /**
      * {@inheritdoc}
      */
-    public $serializer = 'Flarum\Api\Serializer\UserSerializer';
+    public $serializer = UserSerializer::class;
 
     /**
      * @var Dispatcher