Flask框架Flask-Principal基本用法实例分析
本文实例讲述了Flask框架Flask-Principal基本用法。分享给大家供大家参考,具体如下:
Flask-Principal是Flask框架的一个扩展,主要主件是Identity,Needs,Permission和IdentityContext。
- Identity:代表用户,从各个位置存储和加载每个请求,包含用户拥有的访问权限。
- Needs:需求是访问控制的最小粒度,代表了这种情况的具体参数。例如:管理用户、可以编辑帖子.
- Permission:权限
- IdentityContext:针对某个权限特定的上下文,可用作上下文管理器或装饰器
安装
pip install flask-principal
初始化
from flask_principal import Principal principal = Principal() principal.init_app(app)
权限管理
permissions.py
from flask-principal import Permission,RoleNeed from functools import wraps # 定义相关角色 NORMAL = "NORMAL" ADMIN = "ADMIN" ROLES = ( ("NORMAL","普通用户"), ("ADMIN","管理员") ) admin_permission = Permission(RoleNeed(ADMIN)) def admin_authority(func): @wraps def decorated_view(*args,**kwargs): if admin_permission.can(): return func(*args,**kwargs) else: return "非Admin用户" return decorated_view
添加Role Model
userinfo.py
from app import login_manager from app.db import Base,engine,session from sqlalchemy import Column,String,Integer,create_engine from sqlalchemy_utils.types.choice import ChoiceType from flask_login import UserMixin from permissions import ADMIN,ROLES class User(Base,UserMixin): __tablename__ = "user" id = Column(Integer,primary_key=True) user = Column(String(16)) password = Column(String(16)) roles = Column(ChoiceType(ROLES),default=ADMIN) @login_manager.user_loaded def user_loaded(id): return session.query(User).filter_by(id=id).first() Base.metadata.create_all(engine)
使用user_loader
装饰器的回调函数非常重要,它将决定user对象是否在登录状态。试想只有Admin权限操作的事情,那么此用户是必需先登录,否则无法验证Admin权限。更多Flask-Login
相关操作可参考《Flask框架Flask-Login用法》
登录
验证用户与密码等是否正确,后执行Flask-Login
登录操作,记录登录状态,验证用户权限
from app import app from flask import request from flask_login import login_user from flask_principal import current_app,identity_changed,Identity from userinfo import User from app.db import session @app.route("/login",methods=["POST"]) def login(): user = request.form.get("user",None) password = request.form.get("password",None) if not user or not password: ... user = session.query(User).filter_by(user=user,password=password).first() if not user: ... # 登录 login_user(user) # 发送信号,载入用户权限 identity_changed.send(current_app._get_current_object(),identity=Identity(user.id)) return ...
identity_changed.send()
函数会将sender:current_app._get_current_object()
当前应用app和身份对象和identity:Identity(user.id)
用户对象以信号的新式发送出去,开发者可以用identity_loaded.connect_via(app)
接收信号,并载入权限
from flask_login import current_user from flask_principal import identity_loaded,UserNeed,RoleNeed @identity_loaded.connect_via(app) def on_identity_loaded(sendder,identity): identity.user = current_user if hasattr(current_user,"id"): identity.provides.add(UserNeed(current_user.id)) if hasattr(current_user,"roles"): identity.provides.add(RoleNeed(current_user.roles.code))
实现只有Admin权限用户才能操作删除用户
from app import app from permission import admin_authority @app.route("/delete_user",methods=["POST"]) @admin_authority def delete_user(): ...
希望本文所述对大家基于Flask框架的Python程序设计有所帮助。
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