playscala.scala

  def login_required(email: String, password: String) {
    User.find("byEmail", email).first match {
      case u:User if u.password == password =>
        session.put("user", u.email)
        Application.index
      case u:User => render("reminder", u.email)
      case _ => access_denied
    }
  }

rails.rb

  def login_required
    user = User.first(:email=>params[:email])
    if user and user.password == params[:password]
      return true
    elsif user
      render :partial=>"reminder", :locals=>{:email=>params[:email]}
      return false
    else
      access_denied
    end
  end