登录之后更新导航
- 用上下文处理器app_context_processor定义函数
- 获取session中保存的值
- 返回字典
- 在父模板中更新导航,插入登录状态判断代码。
- 注意用{% ... %}表示指令。
- {{ }}表示变量
- 完成注销功能。
- 清除session
- 跳转
from flask import Flask,render_template,request,redirect,url_for,session from flask_sqlalchemy import SQLAlchemy import config app = Flask(__name__) app.config.from_object(config) db=SQLAlchemy(app) class User(db.Model): __tablename__='user' id=db.Column(db.Integer,primary_key=True,autoincrement=True) username = db.Column(db.String(20), nullable=False) password = db.Column(db.String(20), nullable=False) # db.create_all() @app.route('/') def base(): return render_template('base.html') @app.route('/base2') def base2(): return render_template('base2.html') @app.route('/login/',methods=['GET','POST']) def login(): if request.method =='GET': return render_template('login.html') else: usern = request.form.get('username') passw = request.form.get('password') user = User.query.filter(User.username == usern).first() if user: if user.password == passw: session['user']=usern return redirect(url_for("base2")) else: return u'用户密码错误!' else: return u'用户不存在!' @app.route('/res/',methods=['GET','POST']) def res(): if request.method =='GET': return render_template('res.html') else: usern = request.form.get('name') passw = request.form.get('password') user = User.query.filter(User.username==usern).first() if user: return 'username existed' else: user= User(username=usern,password=passw) db.session.add(user) db.session.commit() return redirect(url_for('login')) @app.context_processor def mycontext(): usern = session.get('user') if usern: return {'username':usern} else: return {} @app.route('/logout') def logout(): session.clear() return redirect(url_for('base')) if __name__ == '__main__': app.run(debug=True)
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>{% block title %}NEWS & JIANSHU{% endblock %}</title> {% block head %}{% endblock %} </head> <body class="bg11"> <nav> <a class="logo" href="http://www.jianshu.com/"> <img src="http://cdn2.jianshu.io/assets/web/logo-58fd04f6f0de908401aa561cda6a0688.png" alt="Logo"></a> <a href="http://127.0.0.1:5000/base2">首页</a> {% if username %} <a href="#">{{ username }}</a> <a href="{{ url_for('logout') }}">注销</a> {% else %} <a href="{{ url_for('login') }}">登陆</a> <a href="{{ url_for('res') }}">注册</a> {% endif %} <input type="text"name="search"> <button type="submit">搜索</button> </nav> <hr> {% block main %}{% endblock %} </body> </html>