How to pass non-column argument to ActiveRecord new?-CodePudding

Let's assume I have a MySQL table like below.

create table users (
    id int,
    full_name varchar(30)
);

and I want to create a model with User.new(id: 1, first_name: "Michael", last_name: "Jackson") but ActiveRecord raises unknown attribute 'first_name' for User..

Userclass is Just an example, I want it to be an meta class(like Employee < User). So, creating build method is not the way really I want.

class User
  attr_accessor :first_name, :last_name
  
  before_create :create_full_name

  def create_full_name
    self.full_name = "#{first_name} #{last_name}"
  end
end 

user = User(id: 1)
user.first_name = "Michael"
user.last_name = "Jackson"

Is pretty close, but this needs an additional assignment from outside. I don't want this redundancy.

Is there any way to this?

CodePudding user response：

You can use the initialize method to set the attributes. You can also use the send method to set the attributes. For example:

class User
  attr_accessor :first_name, :last_name

  def initialize(attributes = {})
    attributes.each do |name, value|
      send("#{name}=", value)
    end
  end
end

user = User.new(id: 1, first_name: "Michael", last_name: "Jackson")
p user.first_name
p user.last_name

# Output:
# "Michael"
# "Jackson"