修复公告列表中用户权限判断错误的情况，抽取代码为 decorator。

announcement/decorators.py

@@ -0,0 +1,43 @@
+# coding=utf-8
+from functools import wraps
+
+from django.http import HttpResponse, HttpResponseRedirect
+from django.shortcuts import render
+
+from utils.shortcuts import error_response, error_page
+
+from account.models import SUPER_ADMIN
+from .models import Announcement
+
+
+def check_user_announcement_permission(func):
+    @wraps(func)
+    def _check_user_announcement_permission(*args, **kwargs):
+        """
+        这个函数检测当前用户能否查看这个公告
+        """
+        # CBV 的情况，第一个参数是self，第二个参数是request
+        if len(args) == 2:
+            request = args[-1]
+        else:
+            request = args[0]
+
+        if "announcement_id" not in kwargs:
+            return error_page(request, u"参数错误")
+        announcement_id = kwargs["announcement_id"]
+
+        try:
+            announcement = Announcement.objects.get(id=announcement_id, visible=True)
+        except Announcement.DoesNotExist:
+            return error_page(request, u"公告不存在")
+
+        # 如果公告是只有部分小组可见的
+        if not announcement.is_global:
+            # 用户必须是登录状态的
+            if not request.user.is_authenticated():
+                return HttpResponseRedirect("/login/")
+            if not announcement.groups.filter(id__in=request.user.group_set.all()).exists():
+                return error_page(request, u"公告不存在")
+        return func(*args, **kwargs)
+
+    return _check_user_announcement_permission

announcement/models.py

@@ -18,7 +18,7 @@ class Announcement(models.Model):
     last_update_time = models.DateTimeField(auto_now=True)
     # 是否可见 false的话相当于删除
     visible = models.BooleanField(default=True)
-    # 公告可见范围 0是全局可见 1是部分小组可见，需要在下面的字段中存储可见的小组
+    # 公告可见范围 True 是全局可见 False 是部分小组可见，需要在下面的字段中存储可见的小组
     is_global = models.BooleanField()
     groups = models.ManyToManyField(Group)
 

announcement/views.py

@@ -10,27 +10,13 @@ from group.models import Group
 from .models import Announcement
 from .serializers import (CreateAnnouncementSerializer, AnnouncementSerializer,
                           EditAnnouncementSerializer)
+from .decorators import check_user_announcement_permission
 
 
+@check_user_announcement_permission
 def announcement_page(request, announcement_id):
-    try:
-        announcement = Announcement.objects.get(id=announcement_id, visible=True)
-    except Announcement.DoesNotExist:
-        return error_page(request, u"公告不存在")
-    # 公开的公告
-    if announcement.is_global == 0:
-        return render(request, "oj/announcement/announcement.html", {"announcement": announcement})
-    else:
-        if not request.user.is_authenticated():
-            return error_page(request, u"公告不存在")
-        # 判断是不是在组里面
-        if request.user.admin_type == SUPER_ADMIN or request.user == announcement.created_by:
-            return render(request, "oj/announcement/announcement.html", {"announcement": announcement})
-        else:
-            if request.user.groups.filter(id__in=[item.id for item in announcement.groups.all()]).exists():
-                return render(request, "oj/announcement/announcement.html", {"announcement": announcement})
-            else:
-                return error_page(request, u"公告不存在")
+    announcement = Announcement.objects.get(id=announcement_id, visible=True)
+    return render(request, "oj/announcement/announcement.html", {"announcement": announcement})
 
 
 class AnnouncementAdminAPIView(APIView):

utils/templatetags/announcement_list.py

@@ -3,6 +3,7 @@ from django import template
 
 from announcement.models import Announcement
 
+
 def public_announcement_list():
     return Announcement.objects.filter(is_global=True, visible=True).order_by("-create_time")