权限组件（5）：权限粒度控制到按钮

效果图：

 一、models层给权限增加url的别名

这是做是为了在模板用别名判断当前用户是否有这个url（权限）
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
                             )

    name = models.CharField(verbose_name='url的别名', max_length=32, unique=True)  # +

    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

注意：刚创建的时候设置成null=True和blank=True,当添加完数据后再设置unique=True，并删除null=True和blank=True

二、在初始化权限中增加别名

把用户权限以字典的形式储存，别名作为key。values还是一个字典，储存其他信息。
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__name',
        'permissions__pid_id',
        'permissions__pid__title',  # +
        'permissions__pid__url',
        'permissions__menu_id',
        'permissions__menu__title',
        'permissions__menu__icon',
    )

    permission_dict = {}  # + 

    menu_dict = {}

    for item in permission_menu_queryset:
        permission_dict[item['permissions__name']] = {
            'id': item['permissions__id'],
            'title': item['permissions__title'],
            'url': item['permissions__url'],
            'pid': item['permissions__pid_id'],
            'p_title': item['permissions__pid__title'],
            'p_url': item['permissions__pid__url'],
        }

        menu_id = item['permissions__menu_id']

        if not menu_id:
            continue

        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_dict
    request.session[settings.MENU_SESSION_KEY] = menu_dict 

三、中间件处理

rbac/middlewares/rbac.py

没有太大变化，换一下名字就行

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

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

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

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

       has_permission = False

       url_record = [
           {'title': '首页', 'url': '#'}
       ]
       for item in permission_dict.values():
           regex = '^%s$' % item['url']
           if re.match(regex, current_path):
               has_permission = True
               request.current_selected_permission = item['pid'] or item['id']
               if not item['pid']:  # 选中的是二级菜单
                   url_record.extend([
                       {'title': item['title'], 'url': item['url'], 'class': 'active'}
                   ])
               else:  # 选中的是具体权限
                   url_record.extend([
                       {'title': item['p_title'], 'url': item['p_url']},
                       {'title': item['title'], 'url': item['url'], 'class': 'active'},
                   ])
               request.breadcrumb = url_record  # 通过request，把储存信息传给用户
               break

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

四、模板处理

在templatestag里判断用户是否有权限（是否有url的别名）
rbac/templatestag/rbac.py

@register.filter()
def has_permission(request, name):
    """判断是否有权限"""

    if name in request.session[settings.PERMISSION_SESSION_KEY]:
        return True

在需要把权限控制到按钮的模板传入request，和url的别名，并进行判断。这里拿用户列表举例
业务app/templates/customer_list.html

{% extends 'layout.html' %}
{% load rbac %}   <!-- 系统会默认找到templatetags的文件下面的rbac模块 -->
...
 {% if request|has_permission:'customer_add' %}
    <a class="btn btn-default" href="/customer/add/">
         <i class="fa fa-plus-square" aria-hidden="true"></i> 添加客户
     </a>
{% endif %}

 {% if request|has_permission:'customer_import' %}
    <a class="btn btn-default" href="/customer/import/">
        <i class="fa fa-file-excel-o" aria-hidden="true"></i> 批量导入
    </a>
{% endif %}

{% if request|has_permission:'customer_edit' or request|has_permission:'customer_del' %}
     <th>选项</th>
{% endif %}

{% if request|has_permission:'customer_edit' or request|has_permission:'customer_del' %}
    <td>
        {% if request|has_permission:'customer_edit' %}
            <a style="color: #333333;" href="/customer/edit/{{ row.id }}/">
                <i class="fa fa-edit" aria-hidden="true"></i>
            </a>
        {% endif %}
        {% if request|has_permission:'customer_del' %}
            |
            <a style="color: #d9534f;" href="/customer/del/{{ row.id }}/">
                <i class="fa fa-trash-o"></i>
            </a>
        {% endif %}
    </td>
{% endif %}
...