Gravatar - Undefined method 'email' for nil:NilClass

Question

I've set up gravatar and have got it working for my 'users/*user id goes here*'. But whenever I try to use it in dashboard/index that's whenever it gives me the error

Undefined method 'email' for nil:NilClass

My dashboard controller is :

class DashboardController < ApplicationController

  def index

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @posts }
    end
  end

end

Dashboard View :

<div class="dash-well">
    <div class="gravatar-dashboard">
        <%= image_tag avatar_url(@user), :class => 'gravatar' %>
        <h1 class="nuvo wtxt"><%= current_user.username.capitalize %></h1>
    </div>
</div>

My Application Helper :

module ApplicationHelper
    def avatar_url(user)
         default_url = "#{root_url}images/guest.png"
         gravatar_id = Digest::MD5.hexdigest(user.email.downcase)
        "http://gravatar.com/avatar/#{gravatar_id}.png?s=200{CGI.escape(default_url)}"
    end

    def avatar_url_small(user)
         default_url = "#{root_url}images/guest.png"
         gravatar_id = Digest::MD5.hexdigest(user.email.downcase)
        "http://gravatar.com/avatar/#{gravatar_id}.png?s=40{CGI.escape(default_url)}"
    end
end

My user model :

class User < ActiveRecord::Base

  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable,
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me, :username, :user_id, :id, :website, :bio, :skype, :dob, :age

  has_many :posts
  # attr_accessible :title, :body
end

My Dashboard Model :

class Dashboard < ActiveRecord::Base
  attr_accessible :status, :author, :email, :username, :id, :user_id, :user, :website, :bio, :skype, :dob, :age

  belongs_to :user
end

Sorry, i'm pretty new to Ruby-On-Rails!

Answer 1

Try this:

<%= image_tag avatar_url(current_user), :class => 'gravatar' %>

Answer 2

You really want this in your controller:

def index
  @user = current_user
  respond_to do |format|
    format.html # index.html.erb
    format.json { render json: @posts }
  end
end

Note the addition of the second line, which assigns the @user variable to the current_user.

Then, the @user you are calling in your view will work. A typical rails pattern that you'll see emerge as you continue to use it is that most variable that begin with the @ symbol will be defined in the corresponding controller method for that view. So, if you are using a variable with @, and it's not available, check the controller to ensure it's defined first. (FYI these are called instance variables if you want to learn more).

To address a second concern, if you are current_user and you wanted to visit another user's page:

def show
  @user = User.find params[:id]
  respond_to do |format|
    format.html # index.html.erb
    format.json { render json: @user }
  end
end

This would work with a URL like /users/1, you can use that very same call to avatar_url, pass the @user, and it will get that user's avatar, where the user is the one that matches the given user ID. You probably already have this exact code in your controller already, but hopefully now you see why it works.

Good luck!