Per-tag permissions!

Pretty easy to implement with the groundwork I’ve done for permissions.
(All the logic is in TagsServiceProvider currently)

extensions/tags/js/src/components/tag-discussion-modal.js

@@ -11,7 +11,7 @@ export default class TagDiscussionModal extends FormModal {
   constructor(props) {
     super(props);
 
-    this.tags = sortTags(app.store.all('tags'));
+    this.tags = sortTags(app.store.all('tags').filter(tag => tag.canStartDiscussion()));
 
     this.selected = m.prop([]);
     if (this.props.selectedTags) {
@@ -28,6 +28,8 @@ export default class TagDiscussionModal extends FormModal {
   }
 
   addTag(tag) {
+    if (!tag.canStartDiscussion()) return;
+
     var selected = this.selected();
     var parent = tag.parent();
     if (parent) {

extensions/tags/js/src/models/tag.js

@@ -21,4 +21,6 @@ Tag.prototype.discussionsCount = Model.prop('discussionsCount');
 Tag.prototype.lastTime = Model.prop('lastTime', Model.date);
 Tag.prototype.lastDiscussion = Model.one('lastDiscussion');
 
+Tag.prototype.canStartDiscussion = Model.prop('canStartDiscussion');
+
 export default Tag;

extensions/tags/migrations/2015_02_24_000000_create_tags_table.php

@@ -26,6 +26,7 @@ class CreateTagsTable extends Migration
             $table->integer('position')->nullable();
             $table->integer('parent_id')->unsigned()->nullable();
             $table->string('default_sort', 50)->nullable();
+            $table->boolean('is_restricted')->default(0);
 
             $table->integer('discussions_count')->unsigned()->default(0);
             $table->integer('last_time')->unsigned()->nullable();

extensions/tags/src/Handlers/TagLoader.php

@@ -0,0 +1,25 @@
+<?php namespace Flarum\Tags\Handlers;
+
+use Flarum\Api\Events\WillRespond;
+use Flarum\Api\Actions\Forum\ShowAction as ForumShowAction;
+use Flarum\Tags\Tag;
+
+class TagLoader
+{
+    public function subscribe($events)
+    {
+        $events->listen('Flarum\Api\Events\WillRespond', __CLASS__.'@whenWillRespond');
+    }
+
+    public function whenWillRespond(WillRespond $event)
+    {
+        if ($event->action instanceof ForumShowAction) {
+            $forum = $event->data;
+
+            $query = Tag::whereVisibleTo($event->request->actor->getUser());
+
+            $forum->tags = $query->with('lastDiscussion')->get();
+            $forum->tags_ids = $forum->tags->lists('id');
+        }
+    }
+}

extensions/tags/src/Handlers/TagSaver.php

@@ -1,9 +1,11 @@
 <?php namespace Flarum\Tags\Handlers;
 
+use Flarum\Tags\Tag;
 use Flarum\Tags\Events\DiscussionWasTagged;
 use Flarum\Core\Events\DiscussionWillBeSaved;
 use Flarum\Core\Events\DiscussionWasDeleted;
 use Flarum\Core\Models\Discussion;
+use Flarum\Core\Exceptions\PermissionDeniedException;
 
 class TagSaver
 {
@@ -25,6 +27,13 @@ class TagSaver
                 $newTagIds[] = (int) $link['id'];
             }
 
+            $newTags = Tag::whereIn('id', $newTagIds);
+            foreach ($newTags as $tag) {
+                if (! $tag->can($user, 'startDiscussion')) {
+                    throw new PermissionDeniedException;
+                }
+            }
+
             $oldTags = [];
 
             if ($discussion->exists) {

extensions/tags/src/Tag.php

@@ -1,9 +1,14 @@
 <?php namespace Flarum\Tags;
 
 use Flarum\Core\Models\Model;
+use Flarum\Core\Support\Locked;
+use Flarum\Core\Support\VisibleScope;
 
 class Tag extends Model
 {
+    use Locked;
+    use VisibleScope;
+
     protected $table = 'tags';
 
     protected $dates = ['last_time'];

extensions/tags/src/TagSerializer.php

@@ -19,6 +19,8 @@ class TagSerializer extends BaseSerializer
      */
     protected function attributes($tag)
     {
+        $user = $this->actor->getUser();
+
         $attributes = [
             'name'             => $tag->name,
             'description'      => $tag->description,
@@ -31,7 +33,8 @@ class TagSerializer extends BaseSerializer
             'position'         => $tag->position === null ? null : (int) $tag->position,
             'defaultSort'      => $tag->default_sort,
             'isChild'          => (bool) $tag->parent_id,
-            'lastTime'         => $tag->last_time ? $tag->last_time->toRFC3339String() : null
+            'lastTime'         => $tag->last_time ? $tag->last_time->toRFC3339String() : null,
+            'canStartDiscussion' => $tag->can($user, 'startDiscussion')
         ];
 
         return $this->extendAttributes($tag, $attributes);
@@ -44,6 +47,6 @@ class TagSerializer extends BaseSerializer
 
     protected function lastDiscussion()
     {
-        return $this->hasOne('Flarum\Api\Serializers\DiscussionSerializer');
+        return $this->hasOne('Flarum\Api\Serializers\DiscussionBasicSerializer');
     }
 }

extensions/tags/src/TagsServiceProvider.php

@@ -6,9 +6,13 @@ use Flarum\Extend\EventSubscribers;
 use Flarum\Extend\Relationship;
 use Flarum\Extend\SerializeRelationship;
 use Flarum\Extend\ApiInclude;
+use Flarum\Extend\ApiLink;
 use Flarum\Extend\Permission;
 use Flarum\Extend\DiscussionGambit;
 use Flarum\Extend\PostType;
+use Flarum\Core\Models\Discussion;
+use Flarum\Core\Models\Post;
+use Flarum\Core\Models\User;
 
 class TagsServiceProvider extends ServiceProvider
 {
@@ -27,7 +31,8 @@ class TagsServiceProvider extends ServiceProvider
 
             new EventSubscribers([
                 'Flarum\Tags\Handlers\DiscussionTaggedNotifier',
-                'Flarum\Tags\Handlers\TagSaver'
+                'Flarum\Tags\Handlers\TagSaver',
+                'Flarum\Tags\Handlers\TagLoader'
             ]),
 
             new Relationship('Flarum\Core\Models\Discussion', 'tags', function ($model) {
@@ -38,25 +43,88 @@ class TagsServiceProvider extends ServiceProvider
 
             new ApiInclude(['discussions.index', 'discussions.show'], 'tags', true),
 
-            new Relationship('Flarum\Core\Models\Forum', 'tags', function ($model) {
-                return Tag::query();
-            }),
-
             new SerializeRelationship('Flarum\Api\Serializers\ForumSerializer', 'hasMany', 'tags', 'Flarum\Tags\TagSerializer'),
 
-            new ApiInclude(['forum.show'], ['tags', 'tags.parent', 'tags.lastDiscussion'], true),
+            new ApiInclude(['forum.show'], ['tags', 'tags.lastDiscussion'], true),
+            new ApiLink(['forum.show'], ['tags.parent'], true),
 
             (new Permission('discussion.tag'))
-                ->serialize()
-                ->grant(function ($grant, $user) {
-                    $grant->where('start_user_id', $user->id);
-                    // @todo add limitations to time etc. according to a config setting
-                }),
+                ->serialize(),
+                // ->grant(function ($grant, $user) {
+                //     $grant->where('start_user_id', $user->id);
+                //     // @todo add limitations to time etc. according to a config setting
+                // }),
 
             new DiscussionGambit('Flarum\Tags\TagGambit'),
 
             new PostType('Flarum\Tags\DiscussionTaggedPost')
         ]);
+
+        Tag::scopeVisible(function ($query, User $user) {
+            $query->whereIn('id', $this->getTagsWithPermission($user, 'view'));
+        });
+
+        Tag::allow('startDiscussion', function (Tag $tag, User $user) {
+            if (! $tag->is_restricted || $user->hasPermission('tag'.$tag->id.'.startDiscussion')) {
+                return true;
+            }
+        });
+
+        Discussion::scopeVisible(function ($query, User $user) {
+            $query->whereNotExists(function ($query) use ($user) {
+                return $query->select(app('db')->raw(1))
+                    ->from('discussions_tags')
+                    ->whereNotIn('tag_id', $this->getTagsWithPermission($user, 'view'))
+                    ->whereRaw('discussion_id = discussions.id');
+            });
+        });
+
+        Discussion::allow('*', function (Discussion $discussion, User $user, $action) {
+            $tags = $discussion->getRelation('tags');
+
+            if (! count($tags)) {
+                return;
+            }
+
+            $restricted = true;
+
+            // If the discussion has a tag that has been restricted, and the user
+            // has this permission for that tag, then they are allowed. If the
+            // discussion only has tags that have been restricted, then the user
+            // *must* have permission for at least one of them. Otherwise, inherit
+            // global permissions.
+            foreach ($tags as $tag) {
+                if ($tag->is_restricted) {
+                    if ($user->hasPermission('tag'.$tag->id.'.discussion.'.$action)) {
+                        return true;
+                    }
+                } else {
+                    $restricted = false;
+                }
+            }
+
+            if ($restricted) {
+                return false;
+            }
+        });
+
+        Post::allow('*', function (Post $post, User $user, $action) {
+            return $post->discussion->can($user, $action.'Posts');
+        });
+    }
+
+    protected function getTagsWithPermission($user, $permission) {
+        static $tags;
+        if (!$tags) $tags = Tag::all();
+
+        $ids = [];
+        foreach ($tags as $tag) {
+            if (! $tag->is_restricted || $user->hasPermission('tag'.$tag->id.'.'.$permission)) {
+                $ids[] = $tag->id;
+            }
+        }
+
+        return $ids;
     }
 
     /**