What is the order of ActiveRecord callbacks and validations?

Question

I was wondering in what order are callbacks and validations called when an ActiveRecord object is created.

Let’s say I have some custom validations & callbacks l

Answer 1

The most-up-to-date version of this list for the latest version of Rails can be found in the ActiveRecord::Callbacks documentation. The lists for Rails 4, 3 & 2 are below.

Rails 4

The most up-to-date version of this list can be found in the Rails 4 Guides.

Creating an object

• before_validation
• after_validation
• before_save
• around_save
• before_create
• around_create
• after_create
• after_save
• after_commit/after_rollback

Updating an object

• before_validation
• after_validation
• before_save
• around_save
• before_update
• around_update
• after_update
• after_save
• after_commit/after_rollback

Destroying an object

• before_destroy
• around_destroy
• after_destroy
• after_commit/after_rollback

Rails 3

The most up-to-date version of this list can be found in the Rails 3 Guides.

Creating an object

• before_validation
• after_validation
• before_save
• around_save
• before_create
• around_create
• after_create
• after_save

Updating an object

• before_validation
• after_validation
• before_save
• around_save
• before_update
• around_update
• after_update
• after_save

Destroying an object

• before_destroy
• around_destroy
• after_destroy

Rails 2

The most up-to-date version of this list can be found in the Rails 2.3 Guides

Creating an object

• before_validation
• before_validation_on_create
• after_validation
• after_validation_on_create
• before_save
• before_create
• INSERT operation
• after_create
• after_save

Updating an object

• before_validation
• before_validation_on_update
• after_validation
• after_validation_on_update
• before_save
• before_update
• UPDATE operation
• after_update
• after_save

Destroying an object

• before_destroy
• DELETE operation
• after_destroy

Since you need to first validate the reference_code, the assign_reference method can be called in the after_validation callback or any callback appearing after it in the list I provided above.

Answer 2

Rails 5

Here is a list with all the available Active Record callbacks, listed in the same order in which they will get called during the respective operations:

1 Creating an Object

• before_validation
• after_validation
• before_save
• around_save
• before_create
• around_create
• after_create
• after_save
• after_commit/after_rollback

2 Updating an Object

• before_validation
• after_validation
• before_save
• around_save
• before_update
• around_update
• after_update
• after_save
• after_commit/after_rollback

3 Destroying an Object

• before_destroy
• around_destroy
• after_destroy
• after_commit/after_rollback

after_save runs both on create and update, but always after the more specific callbacks after_create and after_update, no matter the order in which the macro calls were executed.

before_destroy callbacks should be placed before dependent: :destroy associations (or use the prepend: true option), to ensure they execute before the records are deleted by dependent: :destroy.