Call a specified method on a specific life cycle event.

Here is an example:

require "granite/adapter/pg"
​
class Post < Granite::Base
  connection pg
​
  before_save :upcase_title
​
  column id : Int64, primary: true
  column title : String
  column content : String
  timestamps
​
  def upcase_title
    if title = @title
      @title = title.upcase
    end
  end
end

You can register callbacks for the following events:

Create

• before_save

• before_create

• save

• after_create

• after_save

Update

• before_save

• before_update

• save

• after_update

• after_save

Destroy

• before_destroy

• destroy

• after_destroy