Tags cache issue solved with https://github.com/jenseng/hair_trigger

tags_cache_issue.diff

diff --git a/README.md b/README.md
index e4e7348..3aa3845 100644
--- a/README.md
+++ b/README.md
@@ -29,6 +29,10 @@ Okta trial information you can find [here](https://monterail.hackpad.com/Cooleaf
 If there are two ENV variables set: `BASIC_USERNAME` and `BASIC_PASSWORD`
 whole application will be guarded by basic auth.
 
+### Tags Cache
+Tags cache attribute for Role and Persona is updated by database stored procedure on taggings table.
+Checkout details in `app/models/taggins.rb`
+
 ### Testing
 
 We are using [poltergeist](https://github.com/jonleighton/poltergeist/tree/v1.5.0) - see [installation instructions](https://github.com/jonleighton/poltergeist/tree/v1.5.0#installation)
diff --git a/app/controllers/api/v1/hr/structures.rb b/app/controllers/api/v1/hr/structures.rb
index f46c98f..00f3bd4 100644
--- a/app/controllers/api/v1/hr/structures.rb
+++ b/app/controllers/api/v1/hr/structures.rb
@@ -59,7 +59,7 @@ module API::V1::HR
             Tag.transaction do
               role = roles[user[:id].to_i]
               tag = tags[user[:tag].to_i]
-              add_tag_to_role(role, tag)
+              role.tags << tag
             end
           end
         end
@@ -98,11 +98,6 @@ module API::V1::HR
           end
       end
 
-      def add_tag_to_role(role, tag)
-        role.tags << tag
-        role.refresh_tags_cache
-      end
-
       def map_users_hash_with(key)
         permitted_params[:users].try(:map) { |user| user[key].to_i }
       end
diff --git a/app/controllers/api/v1/hr/users.rb b/app/controllers/api/v1/hr/users.rb
index 7af32f2..7489e2d 100644
--- a/app/controllers/api/v1/hr/users.rb
+++ b/app/controllers/api/v1/hr/users.rb
@@ -115,7 +115,6 @@ module API::V1::HR
         Tag.transaction do
           update_structure_tags(role, permitted_params[:structures])
           update_hidden_tags(role, permitted_params[:hidden].uniq)
-          role.refresh_tags_cache
         end
 
         represent role.user, current_organization, with: ::HR::UserRepresenter
diff --git a/app/controllers/api/v1/main/users.rb b/app/controllers/api/v1/main/users.rb
index b3d29ae..7bf6179 100644
--- a/app/controllers/api/v1/main/users.rb
+++ b/app/controllers/api/v1/main/users.rb
@@ -98,7 +98,6 @@ module API::V1::Main
         if role_params = user_params.delete(:role)
           Tag.transaction do
             update_structure_tags(role, role_params[:structures])
-            role.refresh_tags_cache
           end
         end
 
@@ -109,7 +108,6 @@ module API::V1::Main
             role.tags.delete(role.tags.interest)
             role.tags << current_organization.tags.interest.where(id: interests.uniq).
               where(active: true)
-            role.refresh_tags_cache
           end
         end
 
diff --git a/app/models/persona.rb b/app/models/persona.rb
index 9b14528..5833bd8 100644
--- a/app/models/persona.rb
+++ b/app/models/persona.rb
@@ -2,10 +2,4 @@ class Persona < ActiveRecord::Base
   belongs_to :personable, polymorphic: true
   has_many :taggings, as: :taggable, dependent: :destroy
   has_many :tags, through: :taggings
-
-  after_create :refresh_tags_cache
-
-  def refresh_tags_cache
-    self.update_attributes!(tags_cache: tag_ids)
-  end
 end
diff --git a/app/models/role.rb b/app/models/role.rb
index b5ed1eb..51c770f 100644
--- a/app/models/role.rb
+++ b/app/models/role.rb
@@ -17,10 +17,6 @@ class Role < ActiveRecord::Base
 
   scope :active, ->{ where(active: true) }
 
-  def refresh_tags_cache
-    self.update_attributes!(tags_cache: tag_ids)
-  end
-
   def self.for(organization)
     find_by(organization: organization)
   end
diff --git a/app/models/tagging.rb b/app/models/tagging.rb
index 5c66273..e4a8a8f 100644
--- a/app/models/tagging.rb
+++ b/app/models/tagging.rb
@@ -8,4 +8,25 @@ class Tagging < ActiveRecord::Base
   def interest?
     tag.try(:type) == "interest"
   end
+
+  trigger.after(:insert, :delete).
+    declare('row RECORD; tbl_name TEXT; tags_cache_sql TEXT;') do
+      <<-SQL
+        IF TG_OP = 'INSERT' THEN
+          row := NEW;
+        ELSIF TG_OP = 'DELETE' THEN
+          row := OLD;
+        END IF;
+        IF row.taggable_type IN ('Persona', 'Role') THEN
+          tbl_name := LOWER(row.taggable_type) || 's';
+          tags_cache_sql = 'SELECT tag_id FROM taggings'
+                           || ' WHERE taggable_type = ' || quote_literal(row.taggable_type)
+                           || ' AND taggable_id = ' || quote_literal(row.taggable_id);
+
+          EXECUTE 'UPDATE ' || quote_ident(tbl_name)
+                  || ' SET tags_cache = ARRAY(' || tags_cache_sql || ')'
+                  || ' WHERE id = ' || quote_literal(row.taggable_id);
+        END IF;
+      SQL
+    end
 end
diff --git a/app/services/registration_form.rb b/app/services/registration_form.rb
index d856bcb..2597321 100644
--- a/app/services/registration_form.rb
+++ b/app/services/registration_form.rb
@@ -158,7 +158,6 @@ class RegistrationForm
 
   def persist!
     user.save!
-    role.refresh_tags_cache
     registration.destroy
   end
 
diff --git a/db/migrate/20141001110815_create_trigger_taggings_insert_delete.rb b/db/migrate/20141001110815_create_trigger_taggings_insert_delete.rb
new file mode 100644
index 0000000..691997a
--- /dev/null
+++ b/db/migrate/20141001110815_create_trigger_taggings_insert_delete.rb
@@ -0,0 +1,34 @@
+# This migration was auto-generated via `rake db:generate_trigger_migration'.
+# While you can edit this file, any changes you make to the definitions here
+# will be undone by the next auto-generated trigger migration.
+
+class CreateTriggerTaggingsInsertDelete < ActiveRecord::Migration
+  def up
+    create_trigger("taggings_after_insert_delete_row_tr", :generated => true, :compatibility => 1).
+        on("taggings").
+        after(:insert, :delete).
+        declare('row RECORD; tbl_name TEXT; tags_cache_sql TEXT;') do
+      <<-SQL_ACTIONS
+        IF TG_OP = 'INSERT' THEN
+          row := NEW;
+        ELSIF TG_OP = 'DELETE' THEN
+          row := OLD;
+        END IF;
+        IF row.taggable_type IN ('Persona', 'Role') THEN
+          tbl_name := LOWER(row.taggable_type) || 's';
+          tags_cache_sql = 'SELECT tag_id FROM taggings'
+                           || ' WHERE taggable_type = ' || quote_literal(row.taggable_type)
+                           || ' AND taggable_id = ' || quote_literal(row.taggable_id);
+
+          EXECUTE 'UPDATE ' || quote_ident(tbl_name)
+                  || ' SET tags_cache = ARRAY(' || tags_cache_sql || ')'
+                  || ' WHERE id = ' || quote_literal(row.taggable_id);
+        END IF;
+      SQL_ACTIONS
+    end
+  end
+
+  def down
+    drop_trigger("taggings_after_insert_delete_row_tr", "taggings", :generated => true)
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 7a19608..8a24f4b 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20140929154205) do
+ActiveRecord::Schema.define(version: 20141001110815) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -496,4 +496,27 @@ ActiveRecord::Schema.define(version: 20140929154205) do
     t.datetime "updated_at"
   end
 
+  create_trigger("taggings_after_insert_delete_row_tr", :generated => true, :compatibility => 1).
+      on("taggings").
+      after(:insert, :delete).
+      declare('row RECORD; tbl_name TEXT; tags_cache_sql TEXT;') do
+    <<-SQL_ACTIONS
+        IF TG_OP = 'INSERT' THEN
+          row := NEW;
+        ELSIF TG_OP = 'DELETE' THEN
+          row := OLD;
+        END IF;
+        IF row.taggable_type IN ('Persona', 'Role') THEN
+          tbl_name := LOWER(row.taggable_type) || 's';
+          tags_cache_sql = 'SELECT tag_id FROM taggings'
+                           || ' WHERE taggable_type = ' || quote_literal(row.taggable_type)
+                           || ' AND taggable_id = ' || quote_literal(row.taggable_id);
+
+          EXECUTE 'UPDATE ' || quote_ident(tbl_name)
+                  || ' SET tags_cache = ARRAY(' || tags_cache_sql || ')'
+                  || ' WHERE id = ' || quote_literal(row.taggable_id);
+        END IF;
+    SQL_ACTIONS
+  end
+
 end
diff --git a/spec/factories/personas.rb b/spec/factories/personas.rb
index e703f0a..250ab95 100644
--- a/spec/factories/personas.rb
+++ b/spec/factories/personas.rb
@@ -11,7 +11,6 @@ FactoryGirl.define do
       create_list(:interest_tag, 3,
         organization: evaluator.personable.organization,
         personas: [persona])
-      persona.refresh_tags_cache
     end
   end
 
diff --git a/spec/requests/api/v1/hr/structures_spec.rb b/spec/requests/api/v1/hr/structures_spec.rb
index a0277a0..aafec0b 100644
--- a/spec/requests/api/v1/hr/structures_spec.rb
+++ b/spec/requests/api/v1/hr/structures_spec.rb
@@ -11,11 +11,6 @@ describe API::V1::HR::Structures do
     "/v1/hr/structures/#{structure.id}/#{action}"
   end
 
-  def add_tag_to_role(role, tag)
-    role.tags << tag
-    role.refresh_tags_cache
-  end
-
   before do
     Grape::Endpoint.before_each do |endpoint|
       allow(endpoint).to receive(:authenticate!).and_return(true)
@@ -32,8 +27,7 @@ describe API::V1::HR::Structures do
     let(:role)           { user_with_tag.roles.for(organization) }
 
     before do
-      add_tag_to_role(role, tag)
-
+      role.tags << tag
       get api_path_to("users_without_tags"), organization: organization.subdomain
     end
 
@@ -60,7 +54,7 @@ describe API::V1::HR::Structures do
     describe "with no required tags missing in the database" do
       let(:role) { hr.roles.for(organization) }
 
-      before { add_tag_to_role(role, tag) }
+      before { role.tags << tag }
 
       it "should pass" do
         put api_path_to("required"), basic_params