Only update slug if empty or model condition is met

app/models/budget.rb

@@ -180,6 +180,10 @@ class Budget < ActiveRecord::Base
       )
     end
   end
+
+  def generate_slug?
+    slug.nil? || drafting?
+  end
 end
 
 

app/models/budget/group.rb

@@ -13,5 +13,11 @@ class Budget
     def single_heading_group?
       headings.count == 1
     end
+
+    private
+
+    def generate_slug?
+      slug.nil? || budget.drafting?
+    end
   end
 end

app/models/budget/heading.rb

@@ -28,5 +28,11 @@ class Budget
       investments.empty?
     end
 
+    private
+
+    def generate_slug?
+      slug.nil? || budget.drafting?
+    end
+
   end
 end

app/models/concerns/sluggable.rb

@@ -2,7 +2,7 @@ module Sluggable
   extend ActiveSupport::Concern
 
   included do
-    before_validation :generate_slug
+    before_validation :generate_slug, if: :generate_slug?
   end
 
   def generate_slug