Django Session和Cookie是如何實(shí)現(xiàn)記住用戶登錄狀態(tài)的

from django.shortcuts import render, redirect

# 設(shè)置cookie
"""
key: cookie的名字
value: cookie對(duì)應(yīng)的值
max_age: cookie過(guò)期的時(shí)間
"""
response.set_cookie(key, value, max_age)
# 為了安全，有時(shí)候我們會(huì)調(diào)用下面的函數(shù)來(lái)給cookie加鹽
response.set_signed_cookie(key,value,salt='加密鹽',...)

# 獲取cookie 
request.COOKIES.get(key)
request.get_signed_cookie(key, salt="加密鹽", default=None)

# 刪除cookie
reponse.delete_cookie(key)

# 編寫(xiě)裝飾器檢查用戶是否登錄
def check_login(func):
 def inner(request, *args, **kwargs):
  next_url = request.get_full_path()
  # 假設(shè)設(shè)置的cookie的key為login，value為yes
  if request.get_signed_cookie("login", salt="SSS", default=None) == 'yes':
   # 已經(jīng)登錄的用戶，則放行
   return func(request, *args, **kwargs)
  else:
   # 沒(méi)有登錄的用戶，跳轉(zhuǎn)到登錄頁(yè)面
   return redirect(f"/login?next={next_url}")
 return inner

# 編寫(xiě)用戶登錄頁(yè)面的控制函數(shù)
@csrf_exempt
def login(request):
 if request.method == "POST":
  username = request.POST.get("username")
  passwd = request.POST.get("password")
  next_url = request.POST.get("next_url")

  # 對(duì)用戶進(jìn)行驗(yàn)證，假設(shè)用戶名為：aaa, 密碼為123
  if username === 'aaa' and passwd == '123':
   # 執(zhí)行其他邏輯操作，例如保存用戶信息到數(shù)據(jù)庫(kù)等
   # print(f'next_url={next_url}')
   # 登錄成功后跳轉(zhuǎn),否則直接回到主頁(yè)面
   if next_url and next_url != "/logout/":
    response = redirect(next_url)
   else:
    response = redirect("/index/")
   # 若登錄成功，則設(shè)置cookie，加鹽值可自己定義取，這里定義12小時(shí)后cookie過(guò)期
   response.set_signed_cookie("login", 'yes', salt="SSS", max_age=60*60*12)
   return response
  else:
   # 登錄失敗，則返回失敗提示到登錄頁(yè)面
   error_msg = '登錄驗(yàn)證失敗，請(qǐng)重新嘗試'
   return render(request, "app/login.html", {
    'login_error_msg': error_msg,
    'next_url': next_url,
   })
 # 用戶剛進(jìn)入登錄頁(yè)面時(shí)，獲取到跳轉(zhuǎn)鏈接，并保存
 next_url = request.GET.get("next", '')
 return render(request, "app/login.html", {
  'next_url': next_url
 })

# 登出頁(yè)面
def logout(request):
 rep = redirect("/login/")
 # 刪除用戶瀏覽器上之前設(shè)置的cookie
 rep.delete_cookie('login')
 return rep

# 給主頁(yè)添加登錄權(quán)限認(rèn)證
@check_login
def index(request):
 return render(request, "app/index.html")

<form action="{% url 'login' %}" method="post">
    <h2>請(qǐng)使xx賬戶登錄</h2>
    <div>
    <input id="user" type="text" class="form-control" name="username" placeholder="賬戶" required="" />
    </div>
    <div>
    <input id="pwd" type="password" class="form-control" name="password" placeholder="密碼" required="" />
    </div>
    <div >
     <input id="next" type="text" name="next_url" value="{{ next_url }}" />
    </div>
    {% if login_error_msg %}
     <div id="error-msg">
      <span >{{ login_error_msg }}</span>
     </div>
    {% endif %}
    <div>
     <button type="submit" class="btn btn-default" >登錄</button>
    </div>
   </form>

# 設(shè)置session數(shù)據(jù), key是字符串，value可以是任何值
request.session[key] = value
# 獲取 session
request.session.get[key]
# 刪除 session中的某個(gè)數(shù)據(jù)
del request.session[key]
# 清空session中的所有數(shù)據(jù)
request.session.delete()

# 編寫(xiě)裝飾器檢查用戶是否登錄
def check_login(func):
 def inner(request, *args, **kwargs):
  next_url = request.get_full_path()
  # 獲取session判斷用戶是否已登錄
  if request.session.get('is_login'):
   # 已經(jīng)登錄的用戶...
   return func(request, *args, **kwargs)
  else:
   # 沒(méi)有登錄的用戶，跳轉(zhuǎn)剛到登錄頁(yè)面
   return redirect(f"/login?next={next_url}")
 return inner

@csrf_exempt
def login(request):
 if request.method == "POST":
  username = request.POST.get("username")
  passwd = request.POST.get("password")
  next_url = request.POST.get("next_url")
  # 若是有記住密碼功能
  # remember_sign = request.POST.get("check_remember")
  # print(remember_sign)

  # 對(duì)用戶進(jìn)行驗(yàn)證
  if username == 'aaa' and passwd == '123':
   # 進(jìn)行邏輯處理，比如保存用戶與密碼到數(shù)據(jù)庫(kù)

   # 若要使用記住密碼功能，可保存用戶名、密碼到session
   # request.session['user_info'] = {
    # 'username': username,
    # 'password': passwd
   # }
   request.session['is_login'] = True
   # 判斷是否勾選了記住密碼的復(fù)選框
   # if remember_sign == 'on':
   # request.session['is_remember'] = True
   # else:
    # request.session['is_remember'] = False

   # print(f'next_url={next_url}')
   if next_url and next_url != "/logout/":
    response = redirect(next_url)
   else:
    response = redirect("/index/")
   return response
  else:
   error_msg = '登錄驗(yàn)證失敗，請(qǐng)重新嘗試'
   return render(request, "app/login.html", {
    'login_error_msg': error_msg,
    'next_url': next_url,
   })
 next_url = request.GET.get("next", '')
 # 檢查是否勾選了記住密碼功能
 # password, check_value = '', ''
 # user_session = request.session.get('user_info', {})
 # username = user_session.get('username', '')
 # print(user_session)
 #if request.session.get('is_remember'):
 # password = user_session.get('password', '')
 # check_value = 'checked'
 # print(username, password)
 return render(request, "app/login.html", {
  'next_url': next_url,
  # 'user': username,
  # 'password': password,
  # 'check_value': check_value
 })

def logout(request):
 rep = redirect("/login/")
 # request.session.delete()
 # 登出，則刪除掉session中的某條數(shù)據(jù)
 if 'is_login' in request.session:
  del request.session['is_login']
 return rep

@check_login
def index(request):
 return render(request, "autotest/index.html")

   <form action="{% url 'login' %}" method="post">
    <h2>請(qǐng)使xxx賬戶登錄</h2>
    <div>
    <input id="user" type="text" class="form-control" name="username" placeholder="用戶" required="" value="{{ user }}" />
    </div>
    <div>
    <input id="pwd" type="password" class="form-control" name="password" placeholder="密碼" required="" value="{{ password }}" />
    </div>
    <div >
     <input id="next" type="text" name="next_url" value="{{ next_url }}" />
    </div>
    {% if login_error_msg %}
     <div id="error-msg">
      <span >{{ login_error_msg }}</span>
     </div>
    {% endif %}
    // 若設(shè)置了記住密碼功能
    // <div >
    //  <input id="rmb-me" type="checkbox" name="check_remember" {{ check_value }}/>記住密碼
    // </div>
    <div>
     <button type="submit" class="btn btn-default" >登錄</button>
    </div>
   </form>