I have the simplest possible Ruby on Rails class:
class ProductProperty < ApplicationRecord
def initialize
puts 'hello world'
end
end
But when I simply try to instantiate it, I get an ArgumentError:
[1] pry(main)> ProductProperty.new
ArgumentError: wrong number of arguments (given 1, expected 0)
I'm unclear why it thinks I am passing an argument in ("given 1"). Do I need to do something else to be able to write an initialize method that doesn't take arguments?
If you want to do something before, during or after you create/initalize an object you can use callbacks
For example:
class ProductProperty < ApplicationRecord
after_create :do_something_special
def do_something_special
puts "I'm doing something"
end
end
ProductProperty.create #=> "I'm doing something"
there are more callbacks available, so you can call specific methods during the lifecycle of an object.
you might also want to check out active record migrations if you want to persist and change data in your database
after_initialize callback. I needed this to happen when I called .new on the object, well before any of the callbacks related to writing to the database. ( guides.rubyonrails.org/… )
You can add *args.
class ProductProperty < ApplicationRecord
def initialize(*args)
puts 'hello world'
end
end
But I am wondering why you override initialize? You can use active record callbacks for that.
attr_accessors in theinitializemethod based on an array that I can store elsewhere. Open to suggestions if you can think of another way to createattr_accessors based on a class or instance method.