Devise: custom fields not saved after signing up Rails 4 - ruby-on-rails

Question

I have installed devise gem in my app for registration. I have same issue like this question
I have generated Doctor model by
rails generate devise Doctor
And here is doctor.rb
class Doctor < ActiveRecord::Base
# Include default devise modules. Others available are:
# :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
end
I also generated controller by rails generate devise:controllers doctors
class Doctors::RegistrationsController < Devise::RegistrationsController
before_filter :sign_up_params, only: [:create]
before_filter :account_update_params, only: [:update]
#
# # GET /resource/sign_up
# def new
# super
# end
##
## # POST /resource
# def create
# super
# end
##
## # GET /resource/edit
# def edit
# super
# end
##
## # PUT /resource
# def update
# super
# end
##
## # DELETE /resource
# def destroy
# super
# end
protected
def sign_up_params
params.require(:doctor).permit(:first_name, :last_name, :email, :password, :password_confirmation, :gender, :contact_no, :about_me, :certification, :exp_summary, :username)
end
#
def account_update_params
params.require(:doctor).permit(:first_name, :last_name, :email, :password, :password_confirmation, :current_password , :gender, :contact_no, :about_me, :certification, :exp_summary, :username)
end
# protected
# You can put the params you want to permit in the empty array.
#def configure_sign_up_params
# devise_parameter_sanitizer.for(:sign_up) << :first_name, :last_name, :gender, :contact_no, :about_me, :certification, :exp_summary, :username
#end
# You can put the params you want to permit in the empty array.
#def configure_account_update_params
# devise_parameter_sanitizer.for(:account_update) << :first_name, :last_name, :gender, :contact_no, :about_me, :certification, :exp_summary, :username
#end
# The path used after sign up.
# def after_sign_up_path_for(resource)
# super(resource)
# end
# The path used after sign up for inactive accounts.
# def after_inactive_sign_up_path_for(resource)
# super(resource)
# end
end
I have written in routes.rb file devise_for :doctor, :controllers => { sessions: "doctors/sessions"}.
Here is my logs from terminal after submitting Sign_up form
Started POST "/doctor" for 127.0.0.1 at 2014-12-04 16:52:20 +0530
Processing by Devise::RegistrationsController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"8Dd5u5Qq+kLyAI+RaEuoSyjsxteHw4VBndQC+W5yjy0=", "doctor"=>{"username"=>"Test5", "first_name"=>"John", "last_name"=>"Smith", "contact_no"=>"8787878787", "gender"=>"true", "email"=>"john#smith.com", "about_me"=>"Test", "certification"=>"Test", "exp_summary"=>"Test", "password"=>"[FILTERED]", "password_confirmation"=>"[FILTERED]"}, "commit"=>"Sign up"}
Unpermitted parameters: username, first_name, last_name, contact_no, gender, about_me, certification, exp_summary
(0.2ms) BEGIN
Doctor Exists (0.3ms) SELECT 1 AS one FROM `doctors` WHERE `doctors`.`email` = BINARY 'john#smith.com' LIMIT 1
SQL (0.2ms) INSERT INTO `doctors` (`created_at`, `email`, `encrypted_password`, `updated_at`) VALUES ('2014-12-04 11:22:20', 'john#smith.com', '$2a$10$as.WAOu05ET7RUtnsdTC2ucqotK5Ls2Z6iKWI.wW3gSuIwohYfoTW', '2014-12-04 11:22:20')
(116.8ms) COMMIT
(0.1ms) BEGIN
SQL (0.3ms) UPDATE `doctors` SET `current_sign_in_at` = '2014-12-04 11:22:20', `current_sign_in_ip` = '127.0.0.1', `last_sign_in_at` = '2014-12-04 11:22:20', `last_sign_in_ip` = '127.0.0.1', `sign_in_count` = 1, `updated_at` = '2014-12-04 11:22:20' WHERE `doctors`.`id` = 7
(56.6ms) COMMIT
Redirected to http://localhost:3000/
Completed 302 Found in 254ms (ActiveRecord: 174.5ms)
Started GET "/" for 127.0.0.1 at 2014-12-04 16:52:20 +0530
Processing by HomeController#index as HTML
Doctor Load (0.3ms) SELECT `doctors`.* FROM `doctors` WHERE `doctors`.`id` = 7 ORDER BY `doctors`.`id` ASC LIMIT 1
Rendered home/index.html.erb within layouts/application (0.0ms)
Completed 200 OK in 32ms (Views: 30.5ms | ActiveRecord: 0.3ms)
Started GET "/assets/application.css?body=1" for 127.0.0.1 at 2014-12-04 16:52:20 +0530
Started GET "/assets/home.css?body=1" for 127.0.0.1 at 2014-12-04 16:52:20 +0530
Started GET "/assets/jquery.js?body=1" for 127.0.0.1 at 2014-12-04 16:52:20 +0530
Started GET "/assets/jquery_ujs.js?body=1" for 127.0.0.1 at 2014-12-04 16:52:20 +0530
Started GET "/assets/turbolinks.js?body=1" for 127.0.0.1 at 2014-12-04 16:52:20 +0530
Started GET "/assets/application.js?body=1" for 127.0.0.1 at 2014-12-04 16:52:20 +0530
Started GET "/assets/home.js?body=1" for 127.0.0.1 at 2014-12-04 16:52:20 +0530
Why my custom fields are not saved? Where I do mistake?
Update
Controller Structure:
controllers
-> doctors
-> confirmations_controller.rb
-> omniauth_callbacks_controller.rb
-> passwords_controller.rb
-> registrations_controller.rb
-> sessions_controller.rb
-> unlocks_controller.rb
-> application_controller.rb
-> home_controller.rb

Answer 1

EDITED:
Okay! You were trying to override the devise controllers which is not required in your case. Follow these simple steps:
rails g model Doctor
Create your fields except email and password. Devise will take care of that.
rails g devise:install
rails g devise Doctor
In your ApplicationController:
before_action :configure_permitted_parameters, if: :devise_controller?
def configure_permitted_parameters
devise_parameter_sanitizer.for(:sign_up) { |u| u.permit(:username, :address, :phone, :email) }
end

Answer 2

Please try to do like following. Hopes it work for you. :)
class RegistrationsController < Devise::RegistrationsController
def create
devise_parameter_sanitizer.for(:sign_up) << [:first_name, :last_name]
super
end
end