权限组件（3）：默认选中非菜单（二级菜单）

我们要的效果是点中添加、编辑、删除缴费记录，左边的账单列表会被默认选中

一、在权限表里新建一个自关联的字段pid 

rbac/models.py

class Permission(models.Model):
    """
    权限表
    """
    title = models.CharField(verbose_name='标题', max_length=32)
    url = models.CharField(verbose_name='含正则的URL', max_length=128)

    menu = models.ForeignKey(verbose_name='所属菜单', to=Menu, null=True, blank=True,
                             help_text='null表示不是菜单，非null表示是二级菜单', on_delete=models.CASCADE
                             )

    pid = models.ForeignKey(verbose_name='关联的权限', to='Permission', null=True, blank=True, related_name='parents',
                            help_text='对于非菜单权限需要选择一个可以成为菜单的权限，用于做默认展开和选中菜单',
                            on_delete=models.CASCADE
                            )

    def __str__(self):
        return self.title

说明：拿客户列表来举例:

id	title	url	menu_id	pid
1	客户列表	/customer/list/	1	null
2	增加客户	/customer/add/	null	1
3	编辑客户	/customer/edit/(?Pd+)/	null	1
4	删除客户	/customer/del/(?Pd+)/	null	1

没有pid，有menu_id的是二级菜单，有pid，没有menu_id的是具体的权限，是不可以做菜单的。我们的目的是让用户点击增加、编辑、删除客户的时候，客户列表被默认选中

 

二、初始化权限中增加权限id的其父id（也就是pid、二级菜单）

rbac/service/init_permission.py

from permission_learn import settings


def init_permission(current_user, request):
    """
    用户权限的初始化
    :param current_user:  当前登录用户
    :param request:
    :return:
    """

    permission_menu_queryset = current_user.roles.filter(permissions__isnull=False).values(
        'permissions__id',  
        'permissions__title',
        'permissions__url',
        'permissions__pid_id',  # +
        'permissions__menu_id',
        'permissions__menu__title',
        'permissions__menu__icon',
    )

    menu_dict = {}
    permission_list = []

    for item in permission_menu_queryset:
        permission_list.append(
            {'id': item['permissions__id'], 'url': item['permissions__url'], 'pid': item['permissions__pid_id']}
        )

        menu_id = item['permissions__menu_id']

        if not menu_id:
            continue

        # 二级菜单没有pid
        second_menu = {'id':item['permissions__id'],'title': item['permissions__title'], 'url': item['permissions__url']}

        if menu_id in menu_dict:
            menu_dict[menu_id]['second_menu'].append(second_menu)
        else:
            menu_dict[menu_id] = {
                'title': item['permissions__menu__title'],
                'icon': item['permissions__menu__icon'],
                'second_menu': [second_menu, ]
            }

    request.session[settings.PERMISSION_SESSION_KEY] = permission_list
    request.session[settings.MENU_SESSION_KEY] = menu_dict

初始化权限的时候，给具体权限增加了id和它的pid，给二级菜单增加了id，是为了当用户点击具体权限的时候，可以拿到这个权限的pid，然后和二级菜单的id做比较，如果一样就给二级菜单的id加上选中的样式。

 

三、中间件获取到当前点击的权限的二级菜单的id

rbac/middlewares/rbac.py 

import re

from django.utils.deprecation import MiddlewareMixin
from django.shortcuts import HttpResponse
from permission_learn import settings


class RbacMiddleware(MiddlewareMixin):
    def process_request(self, request):
        white_list = settings.WHITE_LIST
        current_path = request.path_info

        for valid_url in white_list:
            if re.match(valid_url, current_path):
                return None

        permission_list = request.session.get(settings.PERMISSION_SESSION_KEY)

        if not permission_list:
            return HttpResponse('请先登录')

        has_permission = False

        for item in permission_list:
            reg = '^%s$' % item['url']
            if re.match(reg, current_path):
                has_permission = True

                # 如果是二级菜单(/customer/list/)，没有pid，采用id，就是二级菜单的id，如果是具体权限(/customer/add/)，就会采用pid，也是二级菜单的id
                request.current_selected_permission = item['pid'] or item['id']  # 前面为True就用前面的，前面为False就用后面的
                break

        if not has_permission:
            return HttpResponse('未获取权限，请先获取权限')

 

四、在templatestag给用户选中的权限的二级菜单加样式

rbac/templatestag/rbac.py

import re
from collections import OrderedDict

from django.conf import settings
from django.template import Library

register = Library()

@register.inclusion_tag('rbac/multi_menu.html')
def multi_menu(request):
    menu_dict = request.session[settings.MENU_SESSION_KEY]


    key_list = sorted(menu_dict)

    ordered_dict = OrderedDict()
    for key in key_list:
        menu = menu_dict[key]
        menu['class'] = 'hide'

        for second_menu in menu['second_menu']:
            # second_menu['id']是二级菜单的id，current_selected_permission是当前所选权限的二级菜单的id
            if second_menu['id'] == request.current_selected_permission:
                second_menu['class'] = 'active'
                menu['class'] = ''

        ordered_dict[key] = menu

    context = {
        'menus': ordered_dict,
    }

    return context