Added trackable_type to activity serializer and fixed user.activities

Signed-off-by: Israel Barreto Sant'Anna <ibsa14@inf.ufpr.br>

app/models/user.rb

@@ -142,7 +142,7 @@ class User < ApplicationRecord
   # return an array of PublicActivity::Activity
   def activities
     condition = '(owner_type = :type AND owner_id = :id) OR (recipient_type = :type AND recipient_id = :id)'
-    PublicActivity::Activity.order('created_at DESC').where(condition, {type: object.class.to_s, id: object.id}).all
+    PublicActivity::Activity.order('created_at DESC').where(condition, {type: self.class.to_s, id: self.id}).all
   end
 
   private

app/serializers/public_activity/activity_serializer.rb

 class PublicActivity::ActivitySerializer < ActiveModel::Serializer
-  attributes :id, :owner, :trackable, :recipient, :parameters, :created_at
+  attributes :id, :owner, :trackable, :trackable_type, :recipient, :parameters, :created_at
 end