权限管理-菜单管理 + 递归生成菜单

from app import models
import re
from functools import wraps
from django.shortcuts import HttpResponse, redirect


class PermissionHelper(object):

    def __init__(self, request, user):
        self.user = user   #userID
        self.request = request  #request对象
        self.current_url = request.path_info  #获取用户输入的当前路径
        self.permission2role_dict = None   #权限显示效果{"/index":"add"}
        self.menu_leaf_list = None   #有url的叶子节点
        self.menu_list = None    #所有的菜单
        self.session_data()   #把所有权限注册到session中

    def session_data(self):
        permission_dict = self.request.session.get("permission_info")   #从session中取出数据
        if permission_dict:   #如果数据在session中存在把数据取出赋值给对象变量
            self.permission2role_dict = permission_dict["permission2role_dict"]
            self.menu_leaf_list = permission_dict["menu_leaf_list"]
            self.menu_list = permission_dict["menu_list"]
        else:
            #如果session不存在从数据库中取出数据注入到session中
            role_list = models.Role.objects.filter(role2userinfo__user=self.user)   #取出当前登录用户的所有角色

            permission2role_list = models.Permission2Action.objects.filter(permission2action2role__role__in=role_list). 
                values("p__url", "a__code").distinct() #取出当前登录用户所有角色的url和antion并去重

            permission2role_dict = {}
            #转换数据格式把数据从queryset中取出存在字典中 权限显示效果{"url":"对应的权限操作"}
            for item in permission2role_list:
                item = {
                    "url": item["p__url"],
                    "code": item["a__code"]
                }
                if item["url"] in permission2role_dict:
                    permission2role_dict[item["url"]].append(item["code"])
                else:
                    permission2role_dict[item["url"]] = [item["code"], ]
            #取出所有url的叶子节点
            menu_leaf_list = list(models.Permission2Action.objects.filter(permission2action2role__role__in=role_list). 
                                  exclude(p__menu__isnull=True).values("p__id", "p__title", "p__url",
                                                                       "p__menu").distinct())
            #取出所有菜单
            menu_list = list(models.Menu.objects.values("id", "title", "parent_id"))
            #把所有权限注入到session中
            self.request.session["permission_info"] = {
                "permission2role_dict": permission2role_dict,
                "menu_leaf_list": menu_leaf_list,
                "menu_list": menu_list
            }
            #第一次登录session中没有数据把数据赋值给对象变量
            self.permission2role_dict = permission2role_dict
            self.menu_leaf_list = menu_leaf_list
            self.menu_list = menu_list

    #生成权限菜单显示效果[{id:1,child:[{id:3,child[{id:5,child:[]}]}]}]
    def menu_data_list(self):
        menu_leaf_dict = {}
        open_menu_leaf_parent_id = None

        for item in self.menu_leaf_list:    #取出所有存在URL的叶子节点
            item = {
                "id": item["p__id"],
                "title": item["p__title"],
                "url": item["p__url"],
                "parent_id": item["p__menu"],
                "child": [],   #添加挂靠的列表
                "status": True,   #添加显示状态
                "open": False,   #添加菜单的激活状态
            }
            if re.match(item["url"], self.current_url):  #匹配URL是否是当前用户输入的URL
                item["open"] = True  #如果匹配成功就激活
                open_menu_leaf_parent_id = item["parent_id"]  #保存当前激活状态的URL的parentid用来匹配上级菜单

            if item["parent_id"] in menu_leaf_dict:  #更改数据结构结果为{1:["id":...,'child':[]]}
                menu_leaf_dict[item["parent_id"]].append(item)
            else:
                menu_leaf_dict[item["parent_id"]] = [item, ]

        menu_dict = {}

        for item in self.menu_list:  #取出所有的菜单并添加child,显示状态和激活状态
            item["child"] = []
            item["status"] = False
            item["open"] = False
            menu_dict[item["id"]] = item #更改数据结构显示为{1:{"id":...},2:{"id":....}}

        while open_menu_leaf_parent_id:   #更改父节点的激活状态如果是当前激活的URL就把当前URL父节点的所有激活状态改为True
            menu_dict[open_menu_leaf_parent_id]["open"] = True
            open_menu_leaf_parent_id = menu_dict[open_menu_leaf_parent_id]["parent_id"]

        for k, v in menu_leaf_dict.items(): #把所有叶子节点的信息挂靠到父节点的child中
            menu_dict[k]["child"] = v
            parent_id = k
            while parent_id:
                menu_dict[parent_id]["status"] = True  #更改所有存在叶子节点的父节点的显示状态
                parent_id = menu_dict[parent_id]["parent_id"]

        result = []

        for row in menu_dict.values():
            if row["parent_id"]:  #遍历菜单把存在parent_id的菜单都挂靠到父节点上
                menu_dict[row["parent_id"]]["child"].append(row)
            else:
                result.append(row)

        return result

    def menu_content(self, content_list): #递归生成所有子菜单
        response = ""
        tpl = """
         <div class="item %s">
            <div class="title">%s</div>
            <div class="content">%s</div>
        </div>
        """
        for row in content_list:
            if not row["status"]:
                continue
            active = ""
            if row["open"]:
                active = "active"
            title = row["title"]
            content = self.menu_content(row["child"])
            if "url" in row:
                response += '<a class="%s" href="%s">%s</a>' % (active, row["url"], row["title"])
            else:
                response += tpl % (active, title, content)
        return response

    def menu_tree(self):  #生成所有父菜单
        response = ""
        tpl = """
            <div class="item %s">
               <div class="title">%s</div>
               <div class="content">%s</div>
           </div>
           """
        for row in self.menu_data_list():
            if not row["status"]:
                continue
            active = ""
            if row["open"]:
                active = "active"
            title = row["title"]
            content = self.menu_content(row["child"])
            response += tpl % (active, title, content)
        return response

    def actions(self):  #取出当前登录的用户的所有操作权限

        action_list = []

        for key, value in self.permission2role_dict.items():
            if re.match(key, self.current_url):
                action_list.append(value)

        return action_list


def permission(func):   #权限验证装饰器
    @wraps(func)
    def inner(request, *args, **kwargs):
        user_id = request.user.pk
        if not user_id:
            return redirect("/login/")
        permission_obj = PermissionHelper(request, user_id)
        action_list = permission_obj.actions()
        if not action_list:
            return HttpResponse("没有权限访问")
        kwargs["menu_str"] = permission_obj.menu_tree()
        kwargs["action_list"] = action_list
        return func(request, *args, **kwargs)
    return inner