Question

I use eval() in an initialize method:

class ActiveRecord::FakedModel

  def initialize(attributes={})
    attributes = {} if not attributes

    attributes.each do |attr_name, value|
      eval("@#{attr_name}=#{value.inspect}")
    end

    @attributes = attributes
  end
...
end

and have a setter for cleaning whitespaces:

class ContactForm < ActiveRecord::FakedModel
  attr_accessor :plz

  def plz=(plz)
    @plz = plz.try(:delete,' ')
  end
...
end

but this setter doesn’t work when I give ‘plz’ in a hash:

c=ContactForm.new(:plz=>' 1  3 3 3 ')
=> #<ContactForm:0x1024e3a10 @attributes={:plz=>" 1  3 3 3 "}, @plz=" 1  3 3 3 ">

Is there anything wrong with using setters in eval?

Answer 1

Your eval statement is not calling the setter method, it is setting the instance variable directly. If you want your constructor to use the setter, use send:

attributes.each do |attr_name, value|
  send "#{attr_name}=", value
end