text: from flask import render_template, redirect, request, url_for, flash
  from flask.ext.login import login_user, logout_user, login_required, \
      current_user
  from . import auth
  from .. import db
  from ..models import User
  from ..email import send_email
  from .forms import LoginForm, RegistrationForm
  
  
  @auth.route('/login', methods=['GET', 'POST'])
  def login():
      form = LoginForm()
      if form.validate_on_submit():
          user = User.query.filter_by(email=form.email.data).first()
          if user is not None and user.verify_password(form.password.data):
              login_user(user, form.remember_me.data)
              return redirect(request.args.get('next') or url_for('main.index'))
          flash('Invalid username or password.')
      return render_template('auth/login.html', form=form)
  
  
  @auth.route('/logout')
  @login_required
  def logout():
      logout_user()
      flash('You have been logged out.')
      return redirect(url_for('main.index'))
  
  
  @auth.route('/register', methods=['GET', 'POST'])
  def register():
      form = RegistrationForm()
      if form.validate_on_submit():
          user = User(email=form.email.data,
                      username=form.username.data,
                      password=form.password.data)
          db.session.add(user)
          db.session.commit()
          flash('You can now login.')
          return redirect(url_for('auth.login'))
      return render_template('auth/register.html', form=form)
  