利用Python的装饰器解决Bottle框架中用户验证问题

def p():
  print 'Hello,world'

def funcfactor(func):
  print 'calling function named', func.__name__
  func()
  print 'end'

funcfactor(p)
# 输出为:
# calling function named p
# Hello,world
# end

def p():
  print 'Hello,world'
def funcfactor(func):
  print 'calling function named', func.__name__
  return func

func = funcfactor(p)
func()
# 输出为:
# calling function named p
Hello,world

def p():
  print 'Hello, world'

def funcfactor(func):
  def wrapper():
    print 'do something at start'
    func()
    print 'do something at end'
  return wrapper

func = funcfactor(p)
func()
#输出为:
# do something at start
# Hello, world
# do something at end

def decorator(func):
  def wrapper():
    print 'do something at start'
    func()
    print 'do something at end'
  return wrapper

@decorator
def p():
  print 'Hello, world'

p()
#输出为:
# do something at start
# Hello, world
# do something at end

def decorator(func):
  def wrapper(*args, **kargs):
    print 'do something at start'
    func(**kargs)
    print 'do something at end'
  return wrapper

@decorator
def p(name):
  print 'Hello', name

p(name="Jim")
#输出为:
# do something at start
# Hello Jim
# do something at end

def blog_auth(func):
  '''
  定义一个装饰器用于装饰需要验证的页面
  装饰器必须放在route装饰器下面
  '''
  # 定义包装函数
  def wrapper(*args, **kargs):
    try:
      # 读取cookie
      user = request.COOKIES['user']
      shell = request.COOKIES['shell']
    except:
      # 出现异常则重定向到登录页面
      redirect('/login')

    # 验证用户数据
    if checkShell(user, shell):
      # 校验成功则返回函数
      return func(**kargs)
    else:
      # 否则则重定向到登录页面
      redirect('/login')
  return wrapper

@route('/admin:#/?#')
@blog_auth
def admin():
  '''
  用于显示后台管理首页
  '''
  TEMPLATE['title'] = '仪表盘 | ' + TEMPLATE['BLOG_NAME']
  TEMPLATE['user'] = request.COOKIES['user']
  articles = []
  for article in db.posts.find().sort("date",DESCENDING).limit(10):
    articles.append(article)

  # 将文章列表交给前台模版
  TEMPLATE['articles'] = articles
  return template('admin.html',TEMPLATE)