mongoid callbacks

a.rb

class A
  include Mongoid::Document

  field :hoge, type: String

  before_validation do
    p 'before_validation'
  end
  before_validation on: :create do
    p 'before_validation on create'
  end
  before_validation on: :update do
    p 'before_validation on update'
  end
  before_create do
    p 'before_create'
  end
  before_update do
    p 'before_update'
  end
  before_save on: :create do
    p 'before_save on create'
  end
  before_save on: :update do
    p 'before_save on update'
  end
end
__END__

# mongoid (6.1.1)

> a = A.new
> a.hoge = 'aaa'
> a.save
"before_validation"
"before_validation on create"
"before_save on create"
"before_save on update"
"before_create"

> A.create(hoge: 'aaa')
"before_validation"
"before_validation on create"
"before_save on create"
"before_save on update"
"before_create"

> a = A.first
> a.hoge = 'bbb'
> a.save
"before_validation"
"before_validation on update"
"before_save on create"
"before_save on update"
"before_update"

> a = A.first
> a.update(hoge: 'bbb')
"before_validation"
"before_validation on update"
"before_save on create"
"before_save on update"
"before_update"