Question

I’m working on a rails application and I’m trying to access this variable and I keep getting undefined method errors, etc.

In my controller, I am doing:

@application = Application.find(params[:id])
@curr_app_id = @application.application_field.last(1)
puts @curr_app_id

and it prints out

#<ApplicationField:0x56678b8>

What type of variable is this, and how can i access it’s ID?

Answer 1

I did some investigation in my IRB console …

1.9.3p0 :018 > puts User.last(1).class # => Array
1.9.3p0 :019 > puts User.last.class    # => User
1.9.3p0 :018 > puts User.last(1) # => #<User:0x00000006f36280>
1.9.3p0 :019 > puts User.last    # => #<User:0x00000006f36280>

Same output, different classes!

Giving an integer to the last method (even if you give 1) results in a Array: Class Array (Ruby 1.9.3) here.

1.9.3p0 :028 > puts User.last(1).id
# => NoMethodError: undefined method `id' for #<Array:0x00000006f2d8d8>

You should use last without parameter:

@application = Application.find(params[:id])
@curr_app_id = @application.application_field.last
# then you should be able to use the object's methods:
puts @curr_app_id.id