Ruby on Rails - getting association data - ruby-on-rails

Question

I´m trying to make a User - Infos association where my User has_many Infos.
I´m trying to call my User Infos on the index form from Users.
By calling <%= user.infos %> on my index.html.erb (Users) it returns me all datas from the Infos table like this:
[#<Info id: 2, name: "Thales Miguel", date: "1989-07-14", area: "An\xC3\xA1lise de Sistemas", comment: "Analista j\xC3\xBAnior de sistemas.", user_id: 1, created_at: "2012-01-16 15:54:29", updated_at: "2012-01-16 15:54:29">]
I assumed that by doing <%= user.infos.comment %> it would return me the "comment" from that user, but all I get is this error:
undefined method `comment' for #<ActiveRecord::Relation:0x3b8ebe8>
What am I doing wrong?
infos_controller:
class InfosController < ApplicationController
def create
#user = User.find(params[:user_id])
#info = #user.infos.create(params[:info])
redirect_to user_path(#user)
end
def destroy
#user = User.find(params[:user_id])
#info = #user.infos.find(params[:id])
#info.destroy
redirect_to user_path(#user)
end
def new
#user = User.new
#user.build_info
end
end
info model:
class Info < ActiveRecord::Base
belongs_to :user
end
user model:
class User < ActiveRecord::Base
validates :login, :presence => true
validates :password, :presence => true,
:length => {:minimum => 5}
has_many :infos, :dependent => :destroy
end

Answer 1

This:
[#<Info id: 2, name: "Thales Miguel", date: "1989-07-14", area: "An\xC3\xA1lise de Sistemas", comment: "Analista j\xC3\xBAnior de sistemas.", user_id: 1, created_at: "2012-01-16 15:54:29", updated_at: "2012-01-16 15:54:29">]
is an array. You have to choose one of the objects. You can't call an attribute value without selecting one of theses objects. Okay, in this case there is only one object but that doesn't matter.

Answer 2

So, collecting all info what written above:
You cannot call user.infos.comment, because the return value of user.infos is an ActiveRecord::Relation in Rails 3.2 and an array in Rails 3.1 and below. Neither ActiveRecord::Relation nor array do not know what it should do with comment method because they don't know anything of the contained objects.
You have multiple solutions for solve this problem.
If user is limited to have only one info:
class User < ActiveRecord::Base
has_one :info, :dependent => :destroy
end
<%= user.info.comment %>
If user can have multiple info objects:
<%- user.infos.each do |info| %>
<%= info.comment %>
<% end -%>
Or
<ul><li>
<%= user.infos.collect(&:comment).join('</li><li>').html_safe %>
</li></ul>
Or if you want to display only the first info:
<%= user.infos.any? ? user.infos.first.comment : "N/A" %>
Be careful the latest solution: user.infos never be nil, but user.infos.first can be nil, so you must check available infos with user.infos.any?

Answer 3

You should do this way:
<% user.infos.each do |info| %>
<%= info.comment %>
<% end %>
As davidb said, <% user.infos %> returns an array. The object of .comment should be an instance.

Answer 4

The problem is
info is a relationship link
that returns an array of info records, if you want to show the first one for example
user.infos[0].comment
or
user.infos.first.comment
if that user don't have infos then return nil