How to initialize an ActiveRecord with values in Rails?

Question

In plain java I'd use:

public User(String name, String email) {
  this.name = name;
  this.email = f(email);
  this.admin = false;
}

---

However, I couldn't find a simple standard way to do in rails (3.2.3), with ActiveRecords.

1. override initialize

def initialize(attributes = {}, options = {})
  @name  = attributes[:name]
  @email = f(attributes[:email])
  @admin = false
end

but it might be missed when creating a record from the DB

2. using the after_initialize callback

by overriding it:

def after_initialize(attributes = {}, options = {})
  ...
end

or with the macro:

after_initialize : my_own_little_init
def my_own_little_init(attributes = {}, options = {})
  ...
end

but there may be some deprecation issues.

There are some other links in SO, but they may be out-of-date.

---

So, what's the correct/standard method to use?

Answer 1

Your default values should be defined in your Schema when they will apply to ALL records. So

def change
  creates_table :posts do |t|
    t.boolean :published, default: false
    t.string :title
    t.text :content
    t.references :author
    t.timestamps
  end
end

Here, every new Post will have false for published. If you want default values at the object level, it's best to use Factory style implementations:

User.build_admin(params)

def self.build_admin(params)
  user = User.new(params)
  user.admin = true
  user
end