ruby-on-rails – Rails 3.1 Mongoid has_secure_password

undefined method `find_by_email' for User:Class

我看到一个类似的帖子(https://stackoverflow.com/questions/6920875/mongoid-and-has-secure-password)但是,按照它的建议完成我仍然得到相同的错误.

这是我的模型：

class User 
  include Mongoid::Document
  include ActiveModel::SecurePassword 

  validates_presence_of :password,:on => :create
  attr_accessible :email,:password,:password_confirmation

  field :email,:type => String
  field :password_digest,:type => String
  has_secure_password
 end

控制器：

class SessionsController < ApplicationController

  def new
  end

  def create
    user = User.find_by_email(params[:email])
    if user && user.authenticate(params[:password])
      session[:user_id] = user.id
      redirect_to root_url,:notice => "Logged in!"
    else
      flash.now.alert = "Invalid email or password"
      render "new"
    end
  end

  def destroy
    session[:user_id] = nil
    redirect_to root_url,:notice => "Logged out!"
  end

end

谢谢.