Question

I recently started to learn ruby on rails and I was able to successfully create an app and add users with devise, also add an avatar to the user with paperclip.

Now I’m having a problem on how to display the avatar throughout the app. The avatar only displays in http:localhost:3000/users/... (within the devise folders) for exemple, but if I try to create a new page, model, controller http://localhost:3000/profile/ for exemple, using the the tag

<%= image_tag @user.avatar.url(:thumb) %>

the page will not load and will return this error

undefined method 'avatar?' for nil:NilClass

It’s probably something really simple, but I can’t figure out how to fix it.

My model user.rb looks like this:

class User < ActiveRecord::Base
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  validates_uniqueness_of :username

  has_attached_file :avatar, :styles => { :medium => "300x300>", :thumb => "100x100>" }

  attr_accessible :name, :username, :email, :password, :password_confirmation, :remember_me, :avatar
  attr_accessor :current_password
end

And my controller looks like this:

class UserController < ApplicationController
  def profile
  end
end

Thanks!

Answer 1

On routes.rb, you should have something like this:

match "profile" => "user#profile"

On your UserController, you should have something like this:

class UserController < ApplicationController
  def profile
    @user = current_user
  end
end

And then you’ll be able to use @user.avatar.url. Also, pay attention that if you don’t have a logged in user, current_user will be nil, and then you will have the error you described, so please add something like this on your controller:

class UserController < ApplicationController
  before_filter :authenticate_user!

  def profile
    @user = current_user
  end
end

And then, when a unauthenticated account tries to access /profile, it’ll be redirected to the login form.