Merge branch 'activity-pub-metadata' into 'develop'

Add metadata provider for ActivityPub alternate links

See merge request pleroma/pleroma!4286

lib/pleroma/web/metadata.ex

@@ -7,6 +7,7 @@ defmodule Pleroma.Web.Metadata do
 
   def build_tags(params) do
     providers = [
+      Pleroma.Web.Metadata.Providers.ActivityPub,
       Pleroma.Web.Metadata.Providers.RelMe,
       Pleroma.Web.Metadata.Providers.RestrictIndexing
       | activated_providers()

lib/pleroma/web/metadata/providers/activity_pub.ex

@@ -0,0 +1,22 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2024 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.Metadata.Providers.ActivityPub do
+  alias Pleroma.Web.Metadata.Providers.Provider
+
+  @behaviour Provider
+
+  @impl Provider
+  def build_tags(%{object: %{data: %{"id" => object_id}}}) do
+    [{:link, [rel: "alternate", type: "application/activity+json", href: object_id], []}]
+  end
+
+  @impl Provider
+  def build_tags(%{user: user}) do
+    [{:link, [rel: "alternate", type: "application/activity+json", href: user.ap_id], []}]
+  end
+
+  @impl Provider
+  def build_tags(_), do: []
+end