How to use cookies with CherryPy
Introduction
CherryPy uses the Cookie module from Python and in particular the SimpleCookie object type to handle cookies.
Sending a cookie to a browser is accomplished by using cherrypy.response.cookie and receiving a cookie from the browser by cherrypy.request.cookie.
Example
This is demonstrated in the following example code where we use a login and logout procedure :
class Root(object):
@cherrypy.expose
def index(self):
return """
<form id="login" action="/doLogin/" method="post">
<label>
Username:
<input name="username" type="text" />
</label>
<label>
Password:
<input name="password" type="password" />
</label>
<input type="submit" value="Login" />
</form>
"""
@cherrypy.expose
def doLogin(self, username, password):
# Set cookie to send
cookie = cherrypy.response.cookie
cookie[‘user’] = username
cookie[‘user’][‘path’] = ‘/’
cookie[‘user’][‘max-age’] = 3600
cookie[‘pass’] = password
cookie[‘pass’][‘path’] = ‘/’
cookie[‘pass’][‘max-age’] = 3600
return ‘Cookie set. You can now <a href="/doLogout/">logout</a>.’
@cherrypy.expose
def doLogout(self):
# Request cookie that is already set
reqcookie = cherrypy.request.cookie
# Response cookie that overwrites the old one and expires
rescookie = cherrypy.response.cookie
for name in reqcookie.keys():
rescookie[name] = name
rescookie[name][‘path’] = ‘/’
rescookie[name][‘max-age’] = 0 # or: rescookie[name]['expires'] = 0
return ‘Logged out succesfully. You can now <a href="/">login</a> again.’
cherrypy.quickstart(Root())
Creating a cookie
It is important to note that
- cookie[name]
- cookie[name]['path']
- cookie[name]['max-age']
are a bare minimum of attributes that you have to set in order to get this working. If you do not set one of these three attributes, the cookie will simply not be set.
Deleting a cookie
Instead of cookie[name]['max-age']=0 you can also use cookie[name]['expires']=0, which results in the same effect of deleting the cookie.
