登录之后更新导航

用上下文处理器app_context_processor定义函数
1. 获取session中保存的值
2. 返回字典
在父模板中更新导航，插入登录状态判断代码。
1. 注意用{% ... %}表示指令。
2. {{ }}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):
    __table__name = '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)
    nickname = db.Column(db.String(50))

db.create_all()


@app.route('/')
def index():
    return render_template('index.html')

@app.route('/regist/',methods=['GET','POST'])
def regist():
    if request.method=='GET':
        return render_template('regist.html')
    else:
        username=request.form.get('username')
        password=request.form.get('password')
        nickname=request.form.get('nickname')
        user=User.query.filter(User.username==username).first()
        if user:
            return u'username existed'
        else:
            user=User (username=username,password=password,nickname=nickname)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for('login'))



@app.route('/login/',methods=['GET','POST'])
def login():
    if request.method=='GET':
        return render_template('login.html')
    else:
        username=request.form.get('username')
        password=request.form.get('password')
        user = User.query.filter(User.username == username).first()
        if user:
            if user.password==password:
                session['user']=username
                return redirect(url_for('index'))
            else:
                return u'password error'
        else:
            return u'username is not existed'



@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('index'))


@app.route('/question/')
def question():
    return render_template('question.html')
if __name__ == '__main__':
    app.run(debug=True)

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>{% block title%}父模板{% endblock %}</title>
    <script src="{{url_for('static',filename='js/base.js') }}" type="text/javascript"></script>
    <link href="{{ url_for('static' ,filename='css/base.css') }}"  rel="stylesheet" type="text/css">

    {% block head %}

    {% endblock %}




</head>
<body>
<nav>
   <img src="https://gss2.bdstatic.com/-fo3dSag_xI4khGkpoWK1HF6hhy/baike/whfpf%3D180%2C140%2C50/sign=9f84efaedc2a60595245b25a4e0905a3/8718367adab44aede0f8bd83b81c8701a18bfb27.jpg">


    <input type="text"name="search">
    <button type="submit">搜索</button>

  {% if username %}
         <a href="#">{{ username }}</a>
         <a href="{{url_for('logout')}}">注销</a>
         {% else %}
         <a href="{{url_for('login')}}">登录</a>
         <a href="{{url_for('regist')}}">注册</a>
        {% endif %}
        
</nav>

       {% block main %} {% endblock %}



<footer>
    <div class="footer_box">
         Copyright@ 2017-2022 个人版权，版权所有
     </div>
 </footer>
{% endblock %}

posted @ 2017-11-24 11:41 062许立帅阅读(155) 评论(0) 收藏举报

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