Active record structure

ar_example.rb

# Rails style guided+
#-------------------- 1. includes and extend --------------
#-------------------- 2. default scope --------------------
#-------------------- 3. inner classes --------------------
#-------------------- 4. constants ------------------------
#-------------------- 5. attr related macros --------------
#-------------------- 6. enums ----------------------------
#-------------------- 7. scopes ---------------------------
#-------------------- 8. has and belongs ------------------
#-------------------- 9. accept nested macros  ------------
#-------------------- 10. validation ----------------------
#-------------------- 11. before/after callbacks ----------
#-------------------- 12. enums related macros ------------
#-------------------- 13. delegate macros -----------------
#-------------------- 14. other macros (like devise's) 
#---------------------    should be placed after the callbacks
#-------------------- 15. public class methods -------------
#-------------------- 16. instance public methods ----------
#-------------------- 17. protected and private methods ----