¿Cómo usar una variable como atributo de objeto en rieles?

Question

tengo un modelo PaymentDetail con el atributo 'home_address_country', para que pueda utilizar

@payment_detail.home_address_country //where @payment_detail is object of that model. 

quiero usar algo como esto: ---

country_attribute=address_type+"_address_country" //where address type is equal to 'home' 
@payment_detail."#{country_attribute}" 

Medios nombre de atributo se almacena en una variable. ¿Cómo puedo hacer esto?

EDITAR

country_attribute=address_type+"_address_country" 
country_list=Carmen::country_names 
eval("@#{country_attribute} = #{country_list}") 

Answer 1

• Reading atributo AR

  @payment_detail.send("#{address_type}_address_country") 
  

  O

  @payment_detail.read_attribute("#{address_type}_address_country") 
  

• Writing atributo AR

  @payment_detail.send("#{address_type}_address_country=", value) 
  

  O

  @payment_detail.write_attribute("#{address_type}_address_country", value) 
  

• Setting instancia de variable

  @payment_detail.instance_variable_set("@#{address_type}_address_country", value) 
  

• Getting instancia de variable

  @payment_detail.instance_variable_get("@#{address_type}_address_country") 
  

Referencia

• enviar método documentation
• read_attribute método documentation
• write_attribute método documentation
• instance_variable_get método documentation
• instance_variable_set método documentation

Answer 2

manera recomendada para Rails 3 es utilizar dictionary-like access:

attr = @payment_detail["#{address_type}_address_country"] 
attr = "new value" 
@payment_detail["#{address_type}_address_country"] = attr 

read_attribute y write_attribute métodos funcionan solo para Rails 2.