Display tag author only proposal or budget investment author

app/helpers/communities_helper.rb

@@ -18,7 +18,12 @@ module CommunitiesHelper
   end
 
   def is_author?(community, participant)
-    community.topics.pluck(:author_id).include?(participant.id)
+    if community.from_proposal?
+      community.proposal.author_id == participant.id
+    else
+      investment = Budget::Investment.where(community_id: community.id).first
+      investment.author_id == participant.id
+    end
   end
 
 end

app/models/community.rb

@@ -4,7 +4,9 @@ class Community < ActiveRecord::Base
   has_many :topics
 
   def participants
-    users_participants = users_who_commented_by(self) + users_who_topics_author_by(self)
+    users_participants = users_who_commented_by +
+                         users_who_topics_author_by +
+                         author_from_community
     users_participants.uniq
   end
 
@@ -14,14 +16,24 @@ class Community < ActiveRecord::Base
 
   private
 
-  def users_who_commented_by(community)
-    topics_ids = community.topics.pluck(:id)
+  def users_who_commented_by
+    topics_ids = topics.pluck(:id)
     query = "comments.commentable_id IN (?)and comments.commentable_type = 'Topic'"
     User.by_comments(query, topics_ids)
   end
 
-  def users_who_topics_author_by(community)
-    author_ids = community.topics.pluck(:author_id)
+  def users_who_topics_author_by
+    author_ids = topics.pluck(:author_id)
     User.by_authors(author_ids)
   end
+
+  def author_from_community
+    if from_proposal?
+      User.where(id: proposal.author_id)
+    else
+      investment = Budget::Investment.where(community_id: id).first
+      User.where(id: investment.author_id)
+    end
+  end
+
 end