Devise and StrongParams - undefined method permit for nil:NilClass

Question

I current use Rails 4 and I move the app from attr_accessible to the StrongParams. So, I have customised Devise controller:

class UsersController < Devise::RegistrationsController
  load_and_authorize_resource

  #...

  def update
    unless @user.userable?
      if params[:selected_person_type] ==  I18n::t('activerecord.attributes.user.individual')
        redirect_to new_individual_path and return
      elsif params[:selected_person_type] == I18n::t('activerecord.attributes.user.legal_entity')
        redirect_to new_legal_entity_path and return
      end
    end

    @avatar = params[:avatar_id].present? ? Avatar.find_by(id: params[:avatar_id]) : @user.avatar

    if params[:user][:password].blank?
      if @user.update_without_password(user_params)
        notice = if @user.unconfirmed_email.present? && Date.today == @user.confirmation_sent_at.to_date
          t('devise.confirmations.send_instructions')
        else
          t('views.messages.notices.personal_data_updated')
        end
        redirect_to edit_user_path(@user), notice: notice and return
      end
    else
      if @user.valid_password?(params[:user][:current_password])
        params[:user].delete("current_password")
        if @user.update_attributes(user_params) && @user.save
          sign_in(@user, bypass: true)
          redirect_to edit_user_path(@user), notice: t('views.messages.notices.personal_data_updated') and return
        end
      else
        @user.errors.add(:current_password, :invalid)
      end
    end

    render action: "edit"
  end

  def create
    if resource.save
      SystemMailer.send_mail(to: resource.email, body: resource.temp_password, subject: I18n.t('mailers.password.new')).deliver if resource.generate_password == '1'

      if request.xhr?
        expire_data_after_sign_in!
        respond_to do |format|
          format.js
        end
      else
        super
      end
    else
      if request.xhr?
        clean_up_passwords(resource)
        respond_to do |format|
          format.js
        end
      else
        super
      end
    end
  end

  private

  def user_params
    if current_user.present?
      params.require(:user).permit(:fullname, :about, :username, :email, :current_password, :password, :password_confirmation)
    end
  end
end

I got the error before:

Failure/Error: post :create, user: attributes_for(:unconfirmed_user)
     ActiveModel::ForbiddenAttributesError:
       ActiveModel::ForbiddenAttributesError

This is because CanCan isn't so compatible with StrongParams, so i tried this fix in ApplicationController:

class ApplicationController < ActionController::Base
  include SimpleCaptcha::ControllerHelpers
  include CaptchaHelper

  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception

  before_filter :cancan_workaround

  rescue_from CanCan::AccessDenied do |e|
    redirect_to '/', flash: { error: I18n.t('views.messages.notices.access_denied') }
  end

  private

  def cancan_workaround
    resource = controller_name.singularize.to_sym
    method = "#{resource}_params"
    params[resource] &&= send(method) if respond_to?(method, true)
  end
end

After that fix i got that error:

UsersController should successfully create user
     Failure/Error: post :create, user: attributes_for(:unconfirmed_user)
     NoMethodError:
       undefined method `permit' for nil:NilClass
     # ./app/controllers/users_controller.rb:75:in 'create'
     # ./spec/controllers/users_controller_spec.rb:10:in `block (3 levels) in <top (required)>'
     # ./spec/controllers/users_controller_spec.rb:9:in `block (2 levels) in <top (required)>'

Here is ./app/controllers/users_controller.rb:75:in 'create' is super call in the action. Any idea how to fix that?

Answer 1

Ok, i got it. Problem was not in Devise, it was with my permissions:

  private

  def user_params
    if current_user.present?
      params.require(:user).permit(:fullname, :about, :username, :email, :current_password, :password, :password_confirmation)
    end
  end

Test evaluated for non-signed user, so when cancan's hook tried to execute this method:

params[resource] &&= send(method) if respond_to?(method, true)

It received nil, because user wasn't signed-in, so hook transformed :user => { ... } into the :user => nil. So, i fixed it via removing current_user.present?.

  private

  def user_params
    params.require(:user).permit(:fullname, :about, :username, :email, :current_password, :password, :password_confirmation)
  end

Not sure how well this solution is secure.

Answer 2

Devise

Devise doesn't work like other Rails input systems - it uses its own backend functionality to process the params. It seems devise automatically permits the email & password params, and its your job to add the other params its parameter_sanitizer

Devise and Strong Parameters

Bottom line is that, according to the Devise documentation, you'll have to use something like this:

#app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
  before_filter :configure_permitted_parameters, if: :devise_controller?

  protected

  def configure_permitted_parameters
    devise_parameter_sanitizer.for(:sign_up) << :username
  end
end