perf(flags): add pagination to flags list (#3931)

extensions/flags/js/src/forum/components/FlagList.tsx

@@ -8,6 +8,8 @@ import HeaderListItem from 'flarum/forum/components/HeaderListItem';
 import type Mithril from 'mithril';
 import type Post from 'flarum/common/models/Post';
 import type FlagListState from '../states/FlagListState';
+import type Flag from '../models/Flag';
+import { Page } from 'flarum/common/states/PaginatedListState';
 
 export interface IFlagListAttrs extends ComponentAttrs {
   state: FlagListState;
@@ -16,23 +18,29 @@ export interface IFlagListAttrs extends ComponentAttrs {
 export default class FlagList<CustomAttrs extends IFlagListAttrs = IFlagListAttrs> extends Component<CustomAttrs, FlagListState> {
   oninit(vnode: Mithril.Vnode<CustomAttrs, this>) {
     super.oninit(vnode);
-    this.state = this.attrs.state;
   }
 
   view() {
-    const flags = this.state.cache || [];
+    const state = this.attrs.state;
 
     return (
       <HeaderList
         className="FlagList"
         title={app.translator.trans('flarum-flags.forum.flagged_posts.title')}
-        hasItems={flags.length}
-        loading={this.state.loading}
+        hasItems={state.hasItems()}
+        loading={state.isLoading()}
         emptyText={app.translator.trans('flarum-flags.forum.flagged_posts.empty_text')}
+        loadMore={() => state.hasNext() && !state.isLoadingNext() && state.loadNext()}
       >
-        <ul className="HeaderListGroup-content">
-          {!this.state.loading &&
-            flags.map((flag) => {
+        <ul className="HeaderListGroup-content">{this.content(state)}</ul>
+      </HeaderList>
+    );
+  }
+
+  content(state: FlagListState) {
+    if (!state.isLoading() && state.hasItems()) {
+      return state.getPages().map((page: Page<Flag>) => {
+        return page.items.map((flag: Flag) => {
           const post = flag.post() as Post;
 
           return (
@@ -50,15 +58,15 @@ export default class FlagList<CustomAttrs extends IFlagListAttrs = IFlagListAttr
                 datetime={flag.createdAt()}
                 href={app.route.post(post)}
                 onclick={(e: MouseEvent) => {
-                      app.flags.index = post;
                   e.redraw = false;
                 }}
               />
             </li>
           );
-            })}
-        </ul>
-      </HeaderList>
-    );
+        });
+      });
+    }
+
+    return null;
   }
 }

extensions/flags/js/src/forum/components/FlagsDropdown.tsx

@@ -25,7 +25,7 @@ export default class FlagsDropdown<CustomAttrs extends IFlagsDropdownAttrs = IFl
   }
 
   getUnreadCount() {
-    return app.flags.cache ? app.flags.cache.length : app.forum.attribute<number>('flagCount');
+    return app.forum.attribute<number>('flagCount');
   }
 
   getNewCount() {

extensions/flags/js/src/forum/states/FlagListState.tsx

@@ -1,39 +1,33 @@
 import type ForumApplication from 'flarum/forum/ForumApplication';
 import type Flag from '../models/Flag';
-import type Post from 'flarum/common/models/Post';
+import PaginatedListState from 'flarum/common/states/PaginatedListState';
 
-export default class FlagListState {
+export default class FlagListState extends PaginatedListState<Flag> {
   public app: ForumApplication;
-  public loading = false;
-  public cache: Flag[] | null = null;
-  public index: Post | false | null = null;
 
   constructor(app: ForumApplication) {
+    super({}, 1, null);
     this.app = app;
   }
 
+  get type(): string {
+    return 'flags';
+  }
+
   /**
    * Load flags into the application's cache if they haven't already
    * been loaded.
    */
-  load() {
-    if (this.cache && !this.app.session.user!.attribute<number>('newFlagCount')) {
-      return;
+  load(): Promise<void> {
+    if (this.app.session.user?.attribute<number>('newFlagCount')) {
+      this.pages = [];
+      this.location = { page: 1 };
     }
 
-    this.loading = true;
-    m.redraw();
+    if (this.pages.length > 0) {
+      return Promise.resolve();
+    }
 
-    this.app.store
-      .find<Flag[]>('flags')
-      .then((flags) => {
-        this.app.session.user!.pushAttributes({ newFlagCount: 0 });
-        this.cache = flags.sort((a, b) => b.createdAt()!.getTime() - a.createdAt()!.getTime());
-      })
-      .catch(() => {})
-      .then(() => {
-        this.loading = false;
-        m.redraw();
-      });
+    return super.loadNext();
   }
 }

extensions/flags/src/Api/Controller/ListFlagsController.php

@@ -14,6 +14,7 @@ use Flarum\Api\Controller\AbstractListController;
 use Flarum\Flags\Api\Serializer\FlagSerializer;
 use Flarum\Flags\Flag;
 use Flarum\Http\RequestUtil;
+use Flarum\Http\UrlGenerator;
 use Psr\Http\Message\ServerRequestInterface;
 use Tobscure\JsonApi\Document;
 
@@ -28,26 +29,52 @@ class ListFlagsController extends AbstractListController
         'post.discussion'
     ];
 
+    public function __construct(
+        protected UrlGenerator $url
+    ) {
+    }
+
     protected function data(ServerRequestInterface $request, Document $document): iterable
     {
         $actor = RequestUtil::getActor($request);
-        $include = $this->extractInclude($request);
 
         $actor->assertRegistered();
 
         $actor->read_flags_at = Carbon::now();
         $actor->save();
 
-        $flags = Flag::whereVisibleTo($actor)
-            ->latest('flags.created_at')
-            ->groupBy('post_id')
-            ->get();
+        $limit = $this->extractLimit($request);
+        $offset = $this->extractOffset($request);
+        $include = $this->extractInclude($request);
 
         if (in_array('post.user', $include)) {
             $include[] = 'post.user.groups';
         }
 
-        $this->loadRelations($flags, $include);
+        $flags = Flag::whereVisibleTo($actor)
+            ->latest('flags.created_at')
+            ->groupBy('post_id')
+            ->limit($limit + 1)
+            ->offset($offset)
+            ->get();
+
+        $this->loadRelations($flags, $include, $request);
+
+        $flags = $flags->all();
+
+        $areMoreResults = false;
+
+        if (count($flags) > $limit) {
+            array_pop($flags);
+            $areMoreResults = true;
+        }
+
+        $this->addPaginationData(
+            $document,
+            $request,
+            $this->url->to('api')->route('flags.index'),
+            $areMoreResults ? null : 0
+        );
 
         return $flags;
     }