Connect Twitter Account to existing Devise Account - ruby-on-rails

Question

A user can register through Devise.
After the registration a User should be able to connect his
Twitter Account
In the past i used omniauth to get facebook and twitter connect working. But in this particular Situation i need to LINK a twitter account to an existing Devise Account.
Can anyone give me a helping hand on where to start or read, i'm completely clueless.

Answer 1

gems
gem 'omniauth-twitter'
gem 'omniauth-facebook'
gem 'omniauth-linkedin'
in views
<%= check_connection('Facebook')%>
<%= check_connection('Linkedin')%>
<%= check_connection('Twitter')%>
helpers
def check_connection(provider)
if current_user.has_connection_with(provider)
html = link_to disconnect_path(social: provider.downcase), class: "#{provider}-m phone-verified row" do
content_tag :span, 'Verified', class: "verified"
end
else
html = link_to user_omniauth_authorize_path(provider: provider.downcase), class: "#{provider}-m phone-verified row" do
content_tag :span, 'Click to verify', class: "un-verified"
end
end
end
in user model - for you this might be different
devise :database_authenticatable, :registerable, :confirmable, :lockable,
:recoverable, :rememberable, :trackable, :validatable, :omniauthable,
:omniauth_providers => [:facebook, :twitter, :linkedin]
has_many :authorizations, :dependent => :destroy
def has_connection_with(provider)
auth = self.authorizations.where(provider: provider).first
if auth.present?
auth.token.present?
else
false
end
end
in routes I have
devise_for :users, :controllers => {:registrations => "users/registrations",
:sessions => "users/sessions",
:passwords => "users/passwords",
:omniauth_callbacks => "users/omniauth_callbacks" #<- this one you need
}
create authorization table - see this link uninitialized constant User::Authorization | omniauth
class CreateAuthorizations < ActiveRecord::Migration
def change
create_table :authorizations do |t|
t.string :provider
t.string :uid
t.integer :user_id
t.string :token
t.string :secret
t.string :first_name
t.string :last_name
t.string :name
t.string :link
t.timestamps
end
end
end
OmniauthCallbacksController /controllers/users/...
class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
require 'uuidtools'
def facebook
oauthorize "Facebook"
end
def twitter
oauthorize "Twitter"
end
def linkedin
oauthorize "LinkedIn"
end
def passthru
render :file => "#{Rails.root}/public/404.html", :status => 404, :layout => false
end
private
def oauthorize(kind)
#user = find_for_ouath(kind, env["omniauth.auth"], current_user)
if #user
flash[:notice] = I18n.t "devise.omniauth_callbacks.success", :kind => kind
session["devise.#{kind.downcase}_data"] = env["omniauth.auth"]
sign_in_and_redirect #user, :event => :authentication
end
end
def find_for_ouath(provider, access_token, resource=nil)
user, email, name, uid, auth_attr = nil, nil, nil, {}
case provider
when "Facebook"
uid = access_token['uid']
email = access_token['info']['email']
auth_attr = { :uid => uid, :token => access_token['credentials']['token'],
:secret => nil, :first_name => access_token['info']['first_name'],
:last_name => access_token['info']['last_name'], :name => access_token['info']['name'],
:link => access_token['extra']['raw_info']['link'] }
when "Twitter"
uid = access_token['extra']['raw_info']['id']
name = access_token['extra']['raw_info']['name']
auth_attr = { :uid => uid, :token => access_token['credentials']['token'],
:secret => access_token['credentials']['secret'], :first_name => access_token['info']['first_name'],
:last_name => access_token['info']['last_name'], :name => name,
:link => "http://twitter.com/#{name}" }
when 'LinkedIn'
uid = access_token['uid']
name = access_token['info']['name']
auth_attr = { :uid => uid, :token => access_token['credentials']['token'],
:secret => access_token['credentials']['secret'], :first_name => access_token['info']['first_name'],
:last_name => access_token['info']['last_name'],
:link => access_token['info']['public_profile_url'] }
else
raise 'Provider #{provider} not handled'
end
if resource.nil?
if email
user = find_for_oauth_by_email(email, resource)
elsif uid && name
user = find_for_oauth_by_uid(uid, resource)
if user.nil?
user = find_for_oauth_by_name(name, resource)
end
end
else
user = resource
end
auth = user.authorizations.find_by_provider(provider)
if auth.nil?
auth = user.authorizations.build(:provider => provider)
user.authorizations << auth
end
auth.update_attributes auth_attr
return user
end
def find_for_oauth_by_uid(uid, resource=nil)
user = nil
if auth = Authorization.find_by_uid(uid.to_s)
user = auth.user
end
return user
end
def find_for_oauth_by_email(email, resource=nil)
if user = User.find_by_email(email)
user
else
user = User.new(:email => email, :password => Devise.friendly_token[0,20])
user.save
end
return user
end
def find_for_oauth_by_name(name, resource=nil)
if user = User.find_by_name(name)
user
else
first_name = name
last_name = name
user = User.new(:first_name => first_name, :last_name => last_name, :password => Devise.friendly_token[0,20], :email => "#{UUIDTools::UUID.random_create}#host")
user.save(:validate => false)
end
return user
end
end