Authlogic UserSessionsController

AuthenticationHelpers.rb

module AuthenticationHelpers

  private

  def current_user_session
    return @current_user_session if defined?(@current_user_session)
    @current_user_session = UserSession.find
  end

  def current_user
    return @current_user if defined?(@current_user)
    @current_user = current_user_session && current_user_session.record
  end

  def require_user(format = nil)
    unless current_user
      respond_to do |format|
        format.html do
          store_location
          # flash[:notice] = "You must be logged in to access this page"
          redirect_to new_user_session_url
        end
        format.json do
          render :json => {'errors' => "You must be logged in to access this endpoint"}, :status => 403
        end
      end
      return false
    end
  end

  def require_no_user(format = nil)
    if current_user
      respond_to do |format|
        format.html do
          store_location
          # flash[:notice] = "You must be logged out to access this page"
          redirect_to root_url
        end
        format.json do
          render :json => '"You must be logged out to access this endpoint"', :status => 403
        end
      end
      return false
    end
  end
  
  def require_admin_privileges
    unless current_user && current_user.admin?
      store_location
      redirect_to root_url
    end
  end

  def store_location
    session[:return_to] = request.request_uri
  end

  def redirect_back_or_default(default)
    redirect_to(session[:return_to] || default)
    session[:return_to] = nil
  end
end

UserSessionsController.rb

class UserSessionsController < ApplicationController

  before_filter :require_no_user, :only => [:new, :create]

  before_filter :require_user, :only => [:destroy, :show]
  
  def new
    @user_session = UserSession.new
  end

  def create
    respond_to do |format|
      format.html {
        @user_session = UserSession.new(params[:user_session])
        if @user_session.save
            flash.clear
            redirect_back_or_default root_url
        else
          render :action => :new, :status => 401
        end
      }
      format.json {
        user_session = UserSession.new({
          :login => params[:username],
          :password => params[:password],
          :remember_me => '1'
        })

        if user_session.save
          render :json => {'user_session' => user_session.to_compact_user_session}
        else
          render :json => {'errors' => user_session.errors}, :status => 401
        end
      }
    end
  end

  def show
    respond_to do |format|
      format.html {
        redirect_to root_url
        # Solves the occasional weird json login output we were getting
      }
      format.json {
        render :json => {'user_session' => current_user_session.to_compact_user_session}
      }
    end
  end

  def destroy
    current_user_session.destroy

    respond_to do |format|
      format.html {
        flash[:notice] = "You have been logged out."
        redirect_back_or_default root_url
      }
      format.json {
        head 200
      }
    end
  end
end

Did you also add to_compact_user_session to your UserSession model?