How to get a Gravatar image appear on my app? - ruby-on-rails

Question

I'm following this railscast and got stuck immediately: http://asciicasts.com/episodes/244-gravatar
Whenever I try to edit the index.html file I get this response from the server:
undefined local variable or method `user'.
By the looks of it, it shouldn't seem too difficult. I just need to swap a few lines here and there, but I am having a tough time.
This is what I have in index.html.erb:
<h1>Listing posts</h1>
<% #posts.each do |post| %>
<tr>
<td><%= post.name %></td>
<td><%= post.title %></td>
<td><%= post.content %></td>
<td><%= link_to 'Show', post %></td>
<td><%= link_to 'Edit', edit_post_path(post) %></td>
<td><%= link_to 'Destroy', post, :confirm => 'Are you sure?', :method => :delete %></td>
</tr>
<% end %>
</table>
I would like to change it to this:
<% for user in #users %>
<tr>
<td><%= image_tag avatar_url(user) %></td>
<td><%= user.email %></td>
<td><%= link_to "Show", user %></td>
<td><%= link_to "Edit", edit_user_path(user) %></td>
<td><%= link_to "Destroy", user, :confirm => 'Are you ↵
sure?', :method => :delete %></td>
</tr>
<% end %>
My application helper code:
module ApplicationHelper
def avatar_url(user)
gravatar_id = Digest::MD5::hexdigest(user.email).downcase
"http://gravatar.com/avatar/#{gravatar_id}.png"
end
end
My post controller code:
class PostsController < ApplicationController
# GET /posts
# GET /posts.xml
def index
#posts = Post.all
respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => #posts }
end
end
# GET /posts/1
# GET /posts/1.xml
def show
#post = Post.find(params[:id])
respond_to do |format|
format.html # show.html.erb
format.xml { render :xml => #post }
end
end
# GET /posts/new
# GET /posts/new.xml
def new
#post = Post.new
respond_to do |format|
format.html # new.html.erb
format.xml { render :xml => #post }
end
end
# GET /posts/1/edit
def edit
#post = Post.find(params[:id])
end
# POST /posts
# POST /posts.xml
def create
#post = Post.new(params[:post])
respond_to do |format|
if #post.save
format.html { redirect_to(#post, :notice => 'Post was successfully created.') }
format.xml { render :xml => #post, :status => :created, :location => #post }
else
format.html { render :action => "new" }
format.xml { render :xml => #post.errors, :status => :unprocessable_entity }
end
end
end
# PUT /posts/1
# PUT /posts/1.xml
def update
#post = Post.find(params[:id])
respond_to do |format|
if #post.update_attributes(params[:post])
format.html { redirect_to(#post, :notice => 'Post was successfully updated.') }
format.xml { head :ok }
else
format.html { render :action => "edit" }
format.xml { render :xml => #post.errors, :status => :unprocessable_entity }
end
end
end
# DELETE /posts/1
# DELETE /posts/1.xml
def destroy
#post = Post.find(params[:id])
#post.destroy
respond_to do |format|
format.html { redirect_to(posts_url) }
format.xml { head :ok }
end
end
end

Answer 1

$ rails g scaffold user email:string
run it in console in the root folder of your application, then make needed changes in app/views/users/index.html.erb

Answer 2

In my case using Devise, I followed the same thing and got stuck as it would give me errors. So I replaced;
module ApplicationHelper
def avatar_url(user)
gravatar_id = Digest::MD5::hexdigest(user.email).downcase
"http://gravatar.com/avatar/#{gravatar_id}.png"
end
end
with;
module ApplicationHelper
def avatar_url(user)
gravatar_id = Digest::MD5::hexdigest(current_user.email).downcase
"http://gravatar.com/avatar/#{gravatar_id}.png"
end
end
I've also noticed that using;
wont work unless you capitalize the "User" looking like this;
I'm very fresh and new to this but after doing that everything works in my app. Hope this helps.

Answer 3

class Question < ApplicationRecord
def gravatar
"http://www.gravatar.com/avatar/#{Digest.MD5.hexdigest(email)}"
end
end
Learnt while going through pluralsight