第十四章： 会话、用户和注册

GET / HTTP/1.1
Host: google.com
...

HTTP/1.1 200 OK
Content-Type: text/html
Set-Cookie: PREF=ID=5b14f22bdaf1e81c:TM=1167000671:LM=1167000671;
            expires=Sun, 17-Jan-2038 19:14:07 GMT;
            path=/; domain=.google.com
Server: GWS/2.1
...

GET / HTTP/1.1
Host: google.com
Cookie: PREF=ID=5b14f22bdaf1e81c:TM=1167000671:LM=1167000671
...

def show_color(request):
    if "favorite_color" in request.COOKIES:
        return HttpResponse("Your favorite color is %s" %             request.COOKIES["favorite_color"])
    else:
        return HttpResponse("You don't have a favorite color.")

def set_color(request):
    if "favorite_color" in request.GET:

        # Create an HttpResponse object...
        response = HttpResponse("Your favorite color is now %s" %             request.GET["favorite_color"])

        # ... and set a cookie on the response
        response.set_cookie("favorite_color",
                            request.GET["favorite_color"])

        return response

    else:
        return HttpResponse("You didn't give a favorite color.")

.. table:: 表 14-1: Cookie 选项

   +---------------------------------+---------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   |参数                             |缺省值                     |描述                                                                                                                                                                                |
   +=================================+===========================+====================================================================================================================================================================================+
   |``max_age``                      |``None``                   |cookie需要延续的时间（以秒为单位） 如果参数是\ `` None`` ，这个cookie会延续到浏览器关闭为止。                                                                                       |
   +---------------------------------+---------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``expires``                      |``None``                   |cookie失效的实际日期/时间。 它的格式必须是：\ `` "Wdy, DD-Mth-YY HH:MM:SS GMT"`` 。如果给出了这个参数，它会覆盖\ `` max_age`` 参数。                                                |
   +---------------------------------+---------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``path``                         |``"/"``                    |cookie生效的路径前缀。 浏览器只会把cookie回传给带有该路径的页 面，这样你可以避免将cookie传给站点中的其他的应用。                                                                    |
   |                                 |                           |                                                                                                                                                                                    |
   |                                 |                           |当你不是控制你的站点的顶层时，这样做是特别有用的。                                                                                                                                  |
   +---------------------------------+---------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``domain``                       |``None``                   |这个cookie有效的站点。 你可以使用这个参数设置一个跨站点（cross-domain）的cookie。 比如，\ `` domain=".example.com"`` 可以设置一个在\ `` www.example.com`` 、\ `` www2.example.com`` 以及\ `` an.other.sub.domain.example.com`` 站点下都可读到的cookie。|
   |                                 |                           |                                                                                                                                                                                    |
   |                                 |                           |如果这个参数被设成\ `` None`` ，cookie将只能在设置它的站点下可以读到。                                                                                                              |
   +---------------------------------+---------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``False``                        |``False``                  |如果设置为 ``True`` ，浏览器将通过HTTPS来回传cookie。                                                                                                                               |
   +---------------------------------+---------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

# Set a session value:
request.session["fav_color"] = "blue"

# Get a session value -- this could be called in a different view,
# or many requests later (or both):
fav_color = request.session["fav_color"]

# Clear an item from the session:
del request.session["fav_color"]

# Check if the session has a given key:
if "fav_color" in request.session:
    ...

request.session['_fav_color'] = 'blue' # Don't do this!

request.session = some_other_object # Don't do this!

request.session.foo = 'bar' # Don't do this!

def post_comment(request):
    if request.method != 'POST':
        raise Http404('Only POSTs are allowed')

    if 'comment' not in request.POST:
        raise Http404('Comment not submitted')

    if request.session.get('has_commented', False):
        return HttpResponse("You've already commented.")

    c = comments.Comment(comment=request.POST['comment'])
    c.save()
    request.session['has_commented'] = True
    return HttpResponse('Thanks for your comment!')

def login(request):
    if request.method != 'POST':
        raise Http404('Only POSTs are allowed')
    try:
        m = Member.objects.get(username=request.POST['username'])
        if m.password == request.POST['password']:
            request.session['member_id'] = m.id
            return HttpResponseRedirect('/you-are-logged-in/')
    except Member.DoesNotExist:
        return HttpResponse("Your username and password didn't match.")

def logout(request):
    try:
        del request.session['member_id']
    except KeyError:
        pass
    return HttpResponse("You're logged out.")

def login(request):

    # If we submitted the form...
    if request.method == 'POST':

        # Check that the test cookie worked (we set it below):
        if request.session.test_cookie_worked():

            # The test cookie worked, so delete it.
            request.session.delete_test_cookie()

            # In practice, we'd need some logic to check username/password
            # here, but since this is an example...
            return HttpResponse("You're logged in.")

        # The test cookie failed, so display an error message. If this
        # were a real site, we'd want to display a friendlier message.
        else:
            return HttpResponse("Please enable cookies and try again.")

    # If we didn't post, send the test cookie along with the login form.
    request.session.set_test_cookie()
    return render_to_response('foo/login_form.html')

>>> from django.contrib.sessions.models import Session
>>> s = Session.objects.get(pk='2b1189a188b44ad18c35e113ac6ceead')
>>> s.expire_date
datetime.datetime(2005, 8, 20, 13, 35, 12)

>>> s.session_data
'KGRwMQpTJ19hdXRoX3VzZXJfaWQnCnAyCkkxCnMuMTExY2ZjODI2Yj...'
>>> s.get_decoded()
{'user_id': 42}

# Session is modified.
request.session['foo'] = 'bar'

# Session is modified.
del request.session['foo']

# Session is modified.
request.session['foo'] = {}

# Gotcha: Session is NOT modified, because this alters
# request.session['foo'] instead of request.session.
request.session['foo']['bar'] = 'baz'

if request.user.is_authenticated():
    # Do something for authenticated users.
else:
    # Do something for anonymous users.

.. table:: 表 14-4. ``User`` 对象方法

   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |方法                                                                                         |描述                                                                                                                                                  |
   +=============================================================================================+======================================================================================================================================================+
   |``is_authenticated()``                                                                       |对于真实的User对象，总是返回\ `` True`` 。                                                                                                            |
   |                                                                                             |这是一个分辨用户是否已被鉴证的方法。 它并不意味着任何权限，也不检查用户是否仍是活动的。 它仅说明此用户已被成功鉴证。                                  |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``is_anonymous()``                                                                           |对于\ `` AnonymousUser`` 对象返回\ `` True`` （对于真实的\ `` User`` 对象返回\ `` False`` ）。                                                        |
   |                                                                                             |总的来说，比起这个方法，你应该倾向于使用\ `` is_authenticated()`` 方法。                                                                              |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``get_full_name()``                                                                          |返回\ `` first_name`` 加上\ `` last_name`` ，中间插入一个空格。                                                                                       |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``set_password(passwd)``                                                                     |设定用户密码为指定字符串（自动处理成哈希串）。 实际上没有保存\ ``User``\对象。                                                                        |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |check_password(passwd)                                                                       |如果指定的字符串与用户密码匹配则返回\ ``True``\。 比较时会使用密码哈希表。                                                                            |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``get_group_permissions()``                                                                  |返回一个用户通过其所属组获得的权限字符串列表。                                                                                                        |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``get_all_permissions()``                                                                    |返回一个用户通过其所属组以及自身权限所获得的权限字符串列表。                                                                                          |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``has_perm(perm)``                                                                           |如果用户有指定的权限，则返回\ `` True`` ，此时\ `` perm`` 的格式是\ `` "package.codename"`` 。如果用户已不活动，此方法总是返回\ `` False`` 。         |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |has_perms(perm_list)                                                                         |如果用户拥有\ * 全部* 的指定权限，则返回\ `` True`` 。 如果用户是不活动的，这个方法总是返回\ `` False`` 。                                            |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``has_module_perms(app_label)``                                                              |如果用户拥有给定的\ `` app_label`` 中的任何权限，则返回\ `` True`` 。如果用户已不活动，这个方法总是返回\ `` False`` 。                                |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |get_and_delete_messages()                                                                    |返回一个用户队列中的\ `` Message`` 对象列表，并从队列中将这些消息删除。                                                                               |
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
   |``email_user(subj, msg)``                                                                    |向用户发送一封电子邮件。 这封电子邮件是从\ `` DEFAULT_FROM_EMAIL`` 设置的地址发送的。 你还可以传送一个第三参数：\ `` from_email`` ，以覆盖电邮中的发送地址。|
   +---------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------+

# Set a user's groups:
myuser.groups = group_list

# Add a user to some groups:
myuser.groups.add(group1, group2,...)

# Remove a user from some groups:
myuser.groups.remove(group1, group2,...)

# Remove a user from all groups:
myuser.groups.clear()

# Permissions work the same way
myuser.permissions = permission_list
myuser.permissions.add(permission1, permission2, ...)
myuser.permissions.remove(permission1, permission2, ...)
myuser.permissions.clear()

>>> from django.contrib import auth
>>> user = auth.authenticate(username='john', password='secret')
>>> if user is not None:
...     print "Correct!"
... else:
...     print "Invalid password."

from django.contrib import auth

def login_view(request):
    username = request.POST.get('username', '')
    password = request.POST.get('password', '')
    user = auth.authenticate(username=username, password=password)
    if user is not None and user.is_active:
        # Correct password, and the user is marked "active"
        auth.login(request, user)
        # Redirect to a success page.
        return HttpResponseRedirect("/account/loggedin/")
    else:
        # Show an error page
        return HttpResponseRedirect("/account/invalid/")

from django.contrib import auth

def logout_view(request):
    auth.logout(request)
    # Redirect to a success page.
    return HttpResponseRedirect("/account/loggedout/")

from django.contrib.auth.views import login, logout

urlpatterns = patterns('',
    # existing patterns here...
    (r'^accounts/login/$',  login),
    (r'^accounts/logout/$', logout),
)

{% extends "base.html" %}

{% block content %}

  {% if form.errors %}
    <p class="error">Sorry, that's not a valid username or password</p>
  {% endif %}

  <form action="" method="post">
    <label for="username">User name:</label>
    <input type="text" name="username" value="" id="username">
    <label for="password">Password:</label>
    <input type="password" name="password" value="" id="password">

    <input type="submit" value="login" />
    <input type="hidden" name="next" value="{{ next|escape }}" />
  </form>

{% endblock %}

from django.http import HttpResponseRedirect

def my_view(request):
    if not request.user.is_authenticated():
        return HttpResponseRedirect('/accounts/login/?next=%s' % request.path)
    # ...

def my_view(request):
    if not request.user.is_authenticated():
        return render_to_response('myapp/login_error.html')
    # ...

from django.contrib.auth.decorators import login_required

@login_required
def my_view(request):
    # ...

def vote(request):
    if request.user.is_authenticated() and request.user.has_perm('polls.can_vote')):
        # vote here
    else:
        return HttpResponse("You can't vote in this poll.")

def user_can_vote(user):
    return user.is_authenticated() and user.has_perm("polls.can_vote")

@user_passes_test(user_can_vote, login_url="/login/")
def vote(request):
    # Code here can assume a logged-in user with the correct permission.
    ...

from django.contrib.auth.decorators import permission_required

@permission_required('polls.can_vote', login_url="/login/")
def vote(request):
    # ...

from django.contrib.auth.decorators import login_required
from django.views.generic.date_based import object_detail

@login_required
def limited_object_detail(*args, **kwargs):
    return object_detail(*args, **kwargs)

>>> from django.contrib.auth.models import User
>>> user = User.objects.create_user(username='john',
...                                 email='jlennon@beatles.com',
...                                 password='glass onion')

>>> user.is_staff = True
>>> user.save()

>>> user = User.objects.get(username='john')
>>> user.set_password('goo goo goo joob')
>>> user.save()

hashtype$salt$hash

sha1$a1976$a36cc8cbf81742a8fb52e221aaeab48ed7f58ab4

from django import forms
from django.contrib.auth.forms import UserCreationForm
from django.http import HttpResponseRedirect
from django.shortcuts import render_to_response

def register(request):
    if request.method == 'POST':
        form = UserCreationForm(request.POST)
        if form.is_valid():
            new_user = form.save()
            return HttpResponseRedirect("/books/")
    else:
        form = UserCreationForm()
    return render_to_response("registration/register.html", {
        'form': form,
    })

{% extends "base.html" %}

{% block title %}Create an account{% endblock %}

{% block content %}
  <h1>Create an account</h1>

  <form action="" method="post">
      {{ form.as_p }}
      <input type="submit" value="Create the account">
  </form>
{% endblock %}

{% if user.is_authenticated %}
  <p>Welcome, {{ user.username }}. Thanks for logging in.</p>
{% else %}
  <p>Welcome, new user. Please log in.</p>
{% endif %}

{% if perms.polls %}
  <p>You have permission to do something in the polls app.</p>
  {% if perms.polls.can_vote %}
    <p>You can vote!</p>
  {% endif %}
{% else %}
  <p>You don't have permission to do anything in the polls app.</p>
{% endif %}

def create_playlist(request, songs):
    # Create the playlist with the given songs.
    # ...
    request.user.message_set.create(
        message="Your playlist was added successfully."
    )
    return render_to_response("playlists/create.html",
        context_instance=RequestContext(request))

{% if messages %}
<ul>
    {% for message in messages %}
    <li>{{ message }}</li>
    {% endfor %}
</ul>
{% endif %}