Add Update activity support to first post only

app/models/discourse_activity_pub_activity.rb

@@ -15,6 +15,10 @@ def delete?
     ap_type === DiscourseActivityPub::AP::Activity::Delete.type
   end
 
+  def update?
+    ap_type === DiscourseActivityPub::AP::Activity::Update.type
+  end
+
   def ready?
     case object_type
     when "DiscourseActivityPubActivity"
@@ -51,6 +55,8 @@ def deliver(to_actor_id: nil, delay: nil)
       to_actor_id: to_actor_id
     }
 
+    Jobs.cancel_scheduled_job(:discourse_activity_pub_deliver, args)
+
     if delay
       Jobs.enqueue_in(delay.minutes, :discourse_activity_pub_deliver, args)
       scheduled_at = (Time.now.utc + delay.minutes).iso8601
@@ -80,6 +86,7 @@ def after_deliver
         args = {}
         args[:published_at] = published_at if create?
         args[:deleted_at] = published_at if delete?
+        args[:updated_at] = published_at if update?
         self.object.model.activity_pub_after_publish(args)
       end
     end

app/models/discourse_activity_pub_object.rb

@@ -14,7 +14,7 @@ def ready?(ap_type)
     return true unless local?
 
     case ap_type
-    when DiscourseActivityPub::AP::Activity::Create.type
+    when DiscourseActivityPub::AP::Activity::Create.type, DiscourseActivityPub::AP::Activity::Update.type
       !!model && !model.trashed?
     when DiscourseActivityPub::AP::Activity::Delete.type
       !model || model.trashed?
@@ -33,12 +33,8 @@ def self.handle_model_callback(model, ap_type_sym)
     ap = DiscourseActivityPub::AP::Object.from_type(ap_type_sym)
     return unless model.activity_pub_enabled && ap&.composition?
 
-    if ap_type_sym == :update
-      # We don't currently permit updates after publication
-      return if model.activity_pub_published?
-      # We don't permit updates if object has been deleted
-      return if model.activity_pub_deleted?
-    end
+    # We don't permit updates if object has been deleted
+    return if model.activity_pub_deleted? && ap_type_sym == :update
 
     # If we're pre-publication clear all objects and data.
     if !model.activity_pub_published? && ap_type_sym == :delete
@@ -61,14 +57,19 @@ def self.handle_model_callback(model, ap_type_sym)
 
       object.save!
 
-      if ap_type_sym != :update
-        DiscourseActivityPubActivity.create!(
+      unless !model.activity_pub_published? && ap_type_sym == :update
+        activity_attrs = {
           local: true,
           actor_id: model.activity_pub_actor.id,
           object_id: object.id,
           object_type: 'DiscourseActivityPubObject',
           ap_type: ap.type
+        }
+        unless DiscourseActivityPubActivity.exists?(
+          activity_attrs.merge(published_at: nil)
         )
+          DiscourseActivityPubActivity.create!(activity_attrs)
+        end
       end
     end
   end

app/serializers/discourse_activity_pub/ap/object/note_serializer.rb

@@ -2,7 +2,8 @@
 
 class DiscourseActivityPub::AP::Object::NoteSerializer < DiscourseActivityPub::AP::ObjectSerializer
   attributes :content,
-             :url
+             :url,
+             :updated
 
   def content
     content = object.content
@@ -24,6 +25,10 @@ def include_url?
     object.stored.local? && !deleted?
   end
 
+  def include_updated?
+    object.updated.present?
+  end
+
   def deleted?
     !object.stored.model || object.stored.model.trashed?
   end

assets/javascripts/discourse/initializers/activity-pub-initializer.js

@@ -23,6 +23,10 @@ export default {
         "activity_pub_deleted_at",
         "activity_pub_deleted_at"
       );
+      api.includePostAttributes(
+        "activity_pub_updated_at",
+        "activity_pub_updated_at"
+      );
 
       // TODO (future): PR discourse/discourse to add post infos via api
       api.reopenWidget("post-meta-data", {
@@ -43,6 +47,9 @@ export default {
             if (attrs.activity_pub_deleted_at) {
               time = moment(attrs.activity_pub_deleted_at);
               status = "deleted";
+            } else if (attrs.activity_pub_updated_at) {
+              time = moment(attrs.activity_pub_updated_at);
+              status = "updated";
             } else if (attrs.activity_pub_published_at) {
               time = moment(attrs.activity_pub_published_at);
               status = "published";
@@ -94,6 +101,7 @@ export default {
               activity_pub_scheduled_at: data.model.scheduled_at,
               activity_pub_published_at: data.model.published_at,
               activity_pub_deleted_at: data.model.deleted_at,
+              activity_pub_updated_at: data.model.updated_at,
             };
             this.get("model.postStream")
               .triggerActivityPubStateChange(data.model.id, stateProps)

assets/stylesheets/common/common.scss

@@ -107,7 +107,8 @@
 }
 
 .post-info.activity-pub {
-  &.published .d-icon {
+  &.published .d-icon,
+  &.updated .d-icon {
     color: var(--success);
   }
   &.scheduled .d-icon,

config/locales/client.en.yml

@@ -37,4 +37,5 @@ en:
           published: "Post was published via ActivityPub at %{time}"
           scheduled: "Post is scheduled to be published via ActivityPub at %{time}"
           scheduled_past: "Post was scheduled to be published via ActivityPub at %{time}"
-          deleted: "ActivityPub note was deleted at %{time}"
+          deleted: "ActivityPub note was deleted at %{time}"
+          updated: "Post was updated via ActivityPub at %{time}"

lib/discourse_activity_pub/ap/actor/group.rb

@@ -17,7 +17,8 @@ def can_perform_activity
             accept: [:follow],
             reject: [:follow],
             create: [:note],
-            delete: [:note]
+            delete: [:note],
+            update: [:note]
           }
         end
       end

lib/discourse_activity_pub/ap/object/note.rb

@@ -12,6 +12,10 @@ def content
           stored&.content
         end
 
+        def updated
+          stored&.updated_at.iso8601
+        end
+
         def can_belong_to
           %i(post)
         end

plugin.rb

@@ -226,6 +226,7 @@
   register_post_custom_field_type("activity_pub_scheduled_at", :string)
   register_post_custom_field_type("activity_pub_published_at", :string)
   register_post_custom_field_type("activity_pub_deleted_at", :string)
+  register_post_custom_field_type("activity_pub_updated_at", :string)
 
   add_to_class(:post, :activity_pub_url) do
     "#{DiscourseActivityPub.base_url}#{self.url}"
@@ -251,7 +252,7 @@
     topic.category&.activity_pub_actor
   end
   add_to_class(:post, :activity_pub_after_publish) do |args = {}|
-    if !activity_pub_enabled || (!args[:published_at] && !args[:deleted_at])
+    if !activity_pub_enabled || (args.keys & %i[published_at deleted_at updated_at]).empty?
       return nil
     end
 
@@ -261,6 +262,9 @@
     custom_fields["activity_pub_deleted_at"] = args[:deleted_at] if args[
       :deleted_at
     ]
+    custom_fields["activity_pub_updated_at"] = args[:updated_at] if args[
+      :updated_at
+    ]
     save_custom_fields(true)
 
     activity_pub_publish_state
@@ -278,6 +282,9 @@
   add_to_class(:post, :activity_pub_deleted_at) do
     custom_fields["activity_pub_deleted_at"]
   end
+  add_to_class(:post, :activity_pub_updated_at) do
+    custom_fields["activity_pub_updated_at"]
+  end
   add_to_class(:post, :activity_pub_published?) { !!activity_pub_published_at }
   add_to_class(:post, :activity_pub_deleted?) { !!activity_pub_deleted_at }
   add_to_class(:post, :activity_pub_scheduled_at) do
@@ -295,7 +302,8 @@
         type: "post",
         scheduled_at: self.activity_pub_scheduled_at,
         published_at: self.activity_pub_published_at,
-        deleted_at: self.activity_pub_deleted_at
+        deleted_at: self.activity_pub_deleted_at,
+        updated_at: self.activity_pub_updated_at
       }
     }
     opts = {
@@ -319,6 +327,9 @@
   add_to_serializer(:post, :activity_pub_deleted_at) do
     object.activity_pub_deleted_at
   end
+  add_to_serializer(:post, :activity_pub_updated_at) do
+    object.activity_pub_updated_at
+  end
 
   # TODO (future): discourse/discourse needs to cook earlier for validators.
   # See also discourse/discourse/plugins/poll/lib/poll.rb.
@@ -332,16 +343,6 @@
       "activity_pub_content"
     ] = DiscourseActivityPub::ExcerptParser.get_content(post)
   end
-  on(:before_edit_post) do |post, fields|
-    if fields.has_key?(:raw) && post.activity_pub_published? &&
-         post.activity_pub_content != post.activity_pub_object.content
-      post.errors.add(
-        :base,
-        I18n.t("post.discourse_activity_pub.error.edit_after_publication")
-      )
-      raise ActiveRecord::Rollback
-    end
-  end
   on(:post_edited) do |post, topic_changed, post_revisor|
     DiscourseActivityPubObject.handle_model_callback(post, :update)
   end

spec/fabricators/discourse_activity_pub_activity_fabricator.rb

@@ -51,6 +51,18 @@
   end
 end
 
+Fabricator(:discourse_activity_pub_activity_update, from: :discourse_activity_pub_activity) do
+  ap_type { DiscourseActivityPub::AP::Activity::Update.type }
+  actor { Fabricate(:discourse_activity_pub_actor_group) }
+  object { Fabricate(:discourse_activity_pub_object_note) }
+  local { true }
+
+  after_create do |activity|
+    object.model.custom_fields['activity_pub_published_at'] = Time.now
+    object.model.save_custom_fields(true)
+  end
+end
+
 Fabricator(:discourse_activity_pub_activity_delete, from: :discourse_activity_pub_activity) do
   ap_type { DiscourseActivityPub::AP::Activity::Delete.type }
   actor { Fabricate(:discourse_activity_pub_actor_group) }

spec/jobs/discourse_activity_pub_deliver_spec.rb

@@ -238,5 +238,26 @@ def execute_job(args = {})
         end
       end
     end
+
+    context "when delivering an Update" do
+      let(:activity) { Fabricate(:discourse_activity_pub_activity_update) }
+      let(:person) { Fabricate(:discourse_activity_pub_actor_person) }
+
+      it "performs the right request" do
+        body = activity.ap.json
+        body[:to] = person.ap.id
+
+        expect_request(
+          actor_id: activity.actor.id,
+          uri: person.inbox,
+          body: body
+        )
+        execute_job(
+          activity_id: activity.id,
+          from_actor_id: activity.actor.id,
+          to_actor_id: person.id
+        )
+      end
+    end
   end
 end

spec/lib/discourse_activity_pub/delivery_failure_tracker_spec.rb

@@ -3,9 +3,10 @@
 require 'rails_helper'
 
 describe DiscourseActivityPub::DeliveryFailureTracker do
-  let!(:actor) { Fabricate(:discourse_activity_pub_actor_person) }
   subject { described_class.new(actor.inbox) }
 
+  let!(:actor) { Fabricate(:discourse_activity_pub_actor_person) }
+
   after do
     Discourse.redis.flushdb
   end

spec/lib/post_revisor_spec.rb

@@ -28,18 +28,16 @@
       end
 
       describe "with different note content" do
-        it "adds the right error" do
+        it "does not add an error" do
           subject.revise!(user, raw: "#{post.raw} revision inside note")
-          expect(post.errors.present?).to eq(true)
-          expect(post.errors.messages[:base].first).to eq(
-            I18n.t("post.discourse_activity_pub.error.edit_after_publication")
-          )
+          expect(post.errors.present?).to eq(false)
         end
 
-        it "does not perform the edit" do
-          original_raw = post.raw
-          subject.revise!(user, raw: "#{post.raw} revision inside note")
-          expect(post.reload.raw).to eq(original_raw)
+        it "performs the edit" do
+          updated_raw = "#{post.raw} revision inside note"
+          subject.revise!(user, raw: updated_raw)
+          expect(post.reload.raw).to eq(updated_raw)
+          expect(post.activity_pub_content).to eq(updated_raw)
         end
       end
 

spec/models/discourse_activity_pub_activity_spec.rb

@@ -150,6 +150,16 @@
         end
       end
     end
+
+    it "cancels existing scheduled deliveries" do
+      job_args = {
+        activity_id: accept_activity.id,
+        from_actor_id: accept_activity.actor.id,
+        to_actor_id: accept_activity.object.actor.id
+      }
+      Jobs.expects(:cancel_scheduled_job).with(:discourse_activity_pub_deliver, job_args).once
+      accept_activity.deliver(to_actor_id: accept_activity.object.actor.id)
+    end
   end
 
   describe "#after_deliver" do
@@ -189,6 +199,17 @@
       end
     end
 
+    context "with update activity" do
+      let(:update_activity) { Fabricate(:discourse_activity_pub_activity_update, actor: actor) }
+
+      it "calls activity_pub_after_publish on associated object models" do
+        freeze_time
+        original_time = Time.now.utc.iso8601
+        Post.any_instance.expects(:activity_pub_after_publish).with({ updated_at: original_time }).once
+        update_activity.after_deliver
+      end
+    end
+
     context "with accept activity" do
       let(:accept_activity) { Fabricate(:discourse_activity_pub_activity_accept, actor: actor) }