Ruby-on-rails – Rails: retrieving image from Facebook after Omniauth login with Devise

facebook-graph-apiomniauthruby-on-rails

I setup Facebook login with Devise and omniauth with these instructions https://github.com/plataformatec/devise/wiki/OmniAuth:-Overview

The Devise wiki gives some instructions for getting facebook info from the hash stored in this variable request.env['omniauth.auth'] See bottom for the hash.

For example, Devise wiki has these two methods for the User.rb model

def self.find_for_facebook_oauth(access_token, signed_in_resource=nil)
  data = access_token.extra.raw_info
  if user = User.where(:email => data.email).first
    user
  else # Create a user with a stub password. 
    User.create!(:email => data.email, :password => Devise.friendly_token[0,20]) 
  end
end

def self.new_with_session(params, session)
    super.tap do |user|
      if data = session["devise.facebook_data"] && session["devise.facebook_data"]["extra"]["raw_info"]
        user.email = data["email"]

      end
    end
  end

So, using the hash below, I added the following to those two methods to get the name and image 

def self.find_for_facebook_oauth(access_token, signed_in_resource=nil)
  data = access_token.extra.raw_info
  if user = User.where(:email => data.email).first
    user
  else # Create a user with a stub password. 
    User.create!(:email => data.email, :password => Devise.friendly_token[0,20], :name => data.name, :image => access_token.info.image) #I added access_token.info.image based on first answer
  end
end

def self.new_with_session(params, session)
    super.tap do |user|
      if data = session["devise.facebook_data"] && session["devise.facebook_data"]["extra"]["raw_info"]
        user.email = data["email"]
        user.name = data["name"]
        user.image = access_token.info.image  #i changed this based on first answer below

      end
    end
  end

Then in my view, I added the following to show the user name and image

<p>Name:<%= user.name %></p>
 <p>Image: <%= image_tag user.image %>

However, only the name is showing. No image.

In my database, I have a name and an image column. The name from Facebook is being stored, but the image column says 'nil'

Any ideas how I can get the image to work?

Hash stored in request.env['omniauth.auth'] https://github.com/mkdynamic/omniauth-facebook/blob/master/lib/omniauth/strategies/facebook.rb#L31-47

   info do
        prune!({
          'nickname' => raw_info['username'],
          'email' => raw_info['email'],
          'name' => raw_info['name'],
          'first_name' => raw_info['first_name'],
          'last_name' => raw_info['last_name'],
          'image' => "#{options[:secure_image_url] ? 'https' : 'http'}://graph.facebook.com/#{uid}/picture?type=square",
          'description' => raw_info['bio'],
          'urls' => {
            'Facebook' => raw_info['link'],
            'Website' => raw_info['website']
          },
          'location' => (raw_info['location'] || {})['name'],
          'verified' => raw_info['verified']
        })
      end

Best Answer

The image can be found at env["omniauth.auth"]["info"]["image"]. So in your case, access_token.info.image.

If you want to take a good look at the hash of nested hashes returned and see for yourself where everything is, put this as the first line of your callback controller:

render :text => "<pre>" + env["omniauth.auth"].to_yaml and return

EDIT: Ok, so here's what you need to do:

def self.find_for_facebook_oauth(omniauth)
  if user = User.find_by_email(omniauth.info.email)
    if omniauth.info.image.present?
      user.update_attribute(:image, omniauth.info.image)
    end
    user
  else # Create a user with a stub password. 
    User.create!(:email => omniauth.info.email,
                 :name => omniauth.info.name,
                 :image => omniauth.info.image,
                 :password => Devise.friendly_token[0,20])
  end
end

As for the other method, if I'm not mistaken, it should look like this:

def self.new_with_session(params, session)
  super.tap do |user|
    if omniauth = session["devise.facebook_data"]
      user.email = omniauth.info.email
      user.name = omniauth.info.name
      user.image = omniauth.info.image
    end
  end
end

But when is this method used? It's used by Devise when something goes wrong when creating your user. Imagine that the authentication provider doesn't give you an email (Twitter, for example, does this), what can you do? Well, you can redirect the user to your sign up page where he can complete the signup process. But if you redirect the user, you lose the data received by the oauth. The solution is to put this data into the session.

So in your controller, you should have something like:

if user.save
  sign_in_and_redirect user, :event => :authentication
else
  session["devise.facebook_data"] = env["omniauth.auth"]
  redirect_to new_user_registration_url
end

Another problem, however, is that most of the times the data returned by the authentication provider is too big to fit in the session, so we have to pick exactly what we want to put in the session. Since you are only getting a name and an image, you can trim the extra info like so:

session["devise.facebook_data"] = env["omniauth.auth"].except('extra')
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