Add featured hashtags as an ActivityPub collection (#11595)

app/controllers/activitypub/collections_controller.rb

@@ -12,25 +12,17 @@ class ActivityPub::CollectionsController < ActivityPub::BaseController
 
  def show
  expires_in 3.minutes, public: public_fetch_mode?
- render_with_cache json: collection_presenter, content_type: 'application/activity+json', serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter, skip_activities: true
+ render_with_cache json: collection_presenter, content_type: 'application/activity+json', serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter
  end
 
  private
 
  def set_items
  case params[:id]
  when 'featured'
- @items = begin
- # Because in public fetch mode we cache the response, there would be no
- # benefit from performing the check below, since a blocked account or domain
- # would likely be served the cache from the reverse proxy anyway
-
- if authorized_fetch_mode? && !signed_request_account.nil? && (@account.blocking?(signed_request_account) || (!signed_request_account.domain.nil? && @account.domain_blocking?(signed_request_account.domain)))
- []
- else
- cache_collection(@account.pinned_statuses, Status)
- end
- end
+ @items = for_signed_account { cache_collection(@account.pinned_statuses, Status) }
+ when 'tags'
+ @items = for_signed_account { @account.featured_tags }
  when 'devices'
  @items = @account.devices
  else
@@ -40,7 +32,7 @@ def set_items
 
  def set_size
  case params[:id]
- when 'featured', 'devices'
+ when 'featured', 'devices', 'tags'
  @size = @items.size
  else
  not_found
@@ -51,7 +43,7 @@ def set_type
  case params[:id]
  when 'featured'
  @type = :ordered
- when 'devices'
+ when 'devices', 'tags'
  @type = :unordered
  else
  not_found
@@ -66,4 +58,16 @@ def collection_presenter
  items: @items
  )
  end
+
+ def for_signed_account
+ # Because in public fetch mode we cache the response, there would be no
+ # benefit from performing the check below, since a blocked account or domain
+ # would likely be served the cache from the reverse proxy anyway
+
+ if authorized_fetch_mode? && !signed_request_account.nil? && (@account.blocking?(signed_request_account) || (!signed_request_account.domain.nil? && @account.domain_blocking?(signed_request_account.domain)))
+ []
+ else
+ yield
+ end
+ end
 end

app/lib/activitypub/adapter.rb

@@ -13,7 +13,7 @@ class ActivityPub::Adapter < ActiveModelSerializers::Adapter::Base
  moved_to: { 'movedTo' => { '@id' => 'as:movedTo', '@type' => '@id' } },
  also_known_as: { 'alsoKnownAs' => { '@id' => 'as:alsoKnownAs', '@type' => '@id' } },
  emoji: { 'toot' => 'http://joinmastodon.org/ns#', 'Emoji' => 'toot:Emoji' },
- featured: { 'toot' => 'http://joinmastodon.org/ns#', 'featured' => { '@id' => 'toot:featured', '@type' => '@id' } },
+ featured: { 'toot' => 'http://joinmastodon.org/ns#', 'featured' => { '@id' => 'toot:featured', '@type' => '@id' }, 'featuredTags' => { '@id' => 'toot:featuredTags', '@type' => '@id' } },
  property_value: { 'schema' => 'http://schema.org#', 'PropertyValue' => 'schema:PropertyValue', 'value' => 'schema:value' },
  atom_uri: { 'ostatus' => 'http://ostatus.org#', 'atomUri' => 'ostatus:atomUri' },
  conversation: { 'ostatus' => 'http://ostatus.org#', 'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri', 'conversation' => 'ostatus:conversation' },

app/serializers/activitypub/actor_serializer.rb

@@ -10,7 +10,7 @@ class ActivityPub::ActorSerializer < ActivityPub::Serializer
  :discoverable, :olm
 
  attributes :id, :type, :following, :followers,
- :inbox, :outbox, :featured,
+ :inbox, :outbox, :featured, :featured_tags,
  :preferred_username, :name, :summary,
  :url, :manually_approves_followers,
  :discoverable
@@ -81,6 +81,10 @@ def featured
  account_collection_url(object, :featured)
  end
 
+ def featured_tags
+ account_collection_url(object, :tags)
+ end
+
  def endpoints
  object
  end

app/serializers/activitypub/collection_serializer.rb

@@ -16,6 +16,8 @@ def self.serializer_for(model, options)
  ActivityPub::NoteSerializer
  when 'Device'
  ActivityPub::DeviceSerializer
+ when 'FeaturedTag'
+ ActivityPub::HashtagSerializer
  when 'ActivityPub::CollectionPresenter'
  ActivityPub::CollectionSerializer
  when 'String'

app/serializers/activitypub/hashtag_serializer.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+class ActivityPub::HashtagSerializer < ActivityPub::Serializer
+ include RoutingHelper
+
+ attributes :type, :href, :name
+
+ def type
+ 'Hashtag'
+ end
+
+ def name
+ "##{object.name}"
+ end
+
+ def href
+ if object.class.name == 'FeaturedTag'
+ short_account_tag_url(object.account, object.tag)
+ else
+ tag_url(object)
+ end
+ end
+end