Analyzing the use of cookies in Django

A cookie is a record that a browser leaves on the client, which can be kept in memory or on a hard disk. In Django, it's easy to read and set cookies. Next through this article to share the use of cookies in Django, interested friends to see together

A cookie is a record that a browser leaves on the client, which can be kept in memory or on a hard disk. Because the HTTP request is stateless, the server or client can maintain state in the session by reading the cookie's record. For example, a common application scenario is login status. In Django, it's easy to read and set cookies. The cookie itself is formatted like a dictionary, so it can be obtained via the request key or get, and his settings are set by the Set_cookie of the response object; If you want to cancel the cookie, set the expiration time to the current time.

To obtain a cookie:

Request. cookies[' key ']request.get_signed_cookie (key, Default=raise_error, salt= ', max_age=none)  parameters:    Default: Defaults    Salt: Encryption salt    max_age: Background control Expiration Time

Set Cookies:

Rep = HttpResponse (...) or rep = render (Request, ...) Rep.set_cookie (Key,value,...) Rep.set_signed_cookie (key,value,salt= ' crypto Salt ',...)  Parameters: Key    ,       key    value= ',     value    max_age=none,   timeout time    expires=none,   timeout (IE requires expires , so set it if hasn ' t been already.)    Path= '/',     cookie takes effect path,/indicates root path, Special: Cookie with path can be accessed by any URL of the page    Domain=none,   the cookie is in effect the domain name    secure= False,   HTTPS transport    Httponly=false can  only be transmitted by the HTTP protocol and cannot be obtained by JavaScript (not absolute, the underlying capture can be obtained or overwritten)

Example 1 set a login login interface, an index login successful after the jump interface, if not logged in then automatically jump to the login screen

views.py

def index (reqeust):  # Gets the currently logged-on user  v = reqeust. Cookies.get (' username111 ')  if not V:    return redirect ('/login/')  return render (Reqeust, ' index.html ', {' Current_User ': v})

Note that there are 2 ways to time out a cookie, one is to specify Max_age directly (timeout after n seconds), and one is to specify expires followed by a specific time object

HttpOnly can prohibit JavaScript from getting this value, but in fact there is no bird, chrome or grab bag can easily get all the cookies

Index.html

<! DOCTYPE html>
Login.html



<! DOCTYPE html>
Example 2:

In real life, the function of this authentication cookie is generally written as an adorner, so that it can be called directly on the other functions.

Change the example 1



def auth (func):  def Inner (Reqeust,*args,**kwargs):    v = reqeust. Cookies.get (' username111 ')    if not V:      return redirect ('/login/')    return func (Reqeust, *args,**kwargs)  return Inner@authdef Index (reqeust):  # Gets the currently logged-on user  v = reqeust. Cookies.get (' username111 ')  return render (Reqeust, ' index.html ', {' Current_User ': v})
Example 3: We know we can use FBV or CBV to route the function. Example 2 using the Fbv method, with the CBV can also be achieved

CBV inside, if only intends to decorate a method, then directly in front of the method to add a @method_decorator on the line; If you intend to decorate all the methods in this class, then decorate the top of the entire class

views.py



@method_decorator (Auth,name= ' dispatch ') class Order (views. View):  # @method_decorator (auth)  # def dispatch (self, request, *args, **kwargs):  #   return Super (Order , self). Dispatch (Request, *args, **kwargs)  # @method_decorator (auth)  def get (self,reqeust):    v = reqeust. Cookies.get (' username111 ')    return render (Reqeust, ' index.html ', {' Current_User ': v})  def post (Self,reqeust) :    v = reqeust. Cookies.get (' username111 ')    return render (Reqeust, ' index.html ', {' Current_User ': v}) urls.py url (r ' ^order/', Views. Order.as_view ()),
Example 4 We can also use JavaScript or jquery to set cookies, such as the previous pagination of the code based on, we added a custom display line number of the function.

user_list.html here is a jquery plug-in, so it is easier to read settings cookies, and we also limit the use of cookies, not the default range, but only in the path of/user_list



<! DOCTYPE html>
Views.py gets the number of rows per page from the front end, which is passed to our paging class when instantiated



def user_list (Request):  current_page = Request. Get.get (' P ', 1)  current_page = Int (current_page)  val = Request. Cookies.get (' Per_page_count ', ten)  val = Int (val)  page_obj = pagination. Page (Current_page,len (LIST), val)  data = List[page_obj.start:page_obj.end]  page_str = Page_obj.page_str ("/ user_list/")  return render (Request, ' user_list.html ', {' Li ': data, ' Page_str ': Page_str})