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

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
     <title>
        {% block title %}
        {% endblock %}
        </title>
     <link href="{{ url_for('static',filename='CSS/index.css') }}" rel="stylesheet">
    <script src="{{ url_for('static',filename='JS/index.js') }}"></script>
    {% block head %}
{% endblock %}
</head>
<body id="myBody">
<header>
  <nav>
    <ul>
        <li><a href="{{ url_for("homepage") }}">首页</a></li>
        <li><a href="{{ url_for("question") }}" title="问答" target="_blank">问答</a></li>
        <input type="text"id="search" name="search">
        <button id="button1"type="submit">搜索</button>
        {% if username %}
            <li><a href="#"id="aaa">{{ username }}</a></li>
            <li><a href="{{ url_for("logout") }}">注销</a></li>
        {% else %}
        <li><a href="{{ url_for("login") }}">登录</a></li>
        <li><a href="{{ url_for("register") }}">注册</a></li>
        {% endif %}
        <li><img id="myOnOff" onclick="mySwitch()" src="https://www.runoob.com/images/pic_bulbon.gif"height="30px" width="40px"></li>>
    </ul>

  </nav>
</header>

{% block main %}
{% endblock %}
</body>
<div class="bottom" align="center">
      Copyright@ 2017 个人版权，版权所有　　
 </div>

</html>

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)

db = SQLAlchemy(app)
# 创建用户模型
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 homepage():
    return render_template("homepage.html")

@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
                sessionpermanent = True
                return redirect(url_for('homepage'))
            else:
                return 'password error'
        else:
            return 'username is not existed'


@app.route("/register/",methods=['GET','POST'])
def register():
    if request.method == "GET":
        return render_template("register.html")
    else:
        username = request.form.get("username")
        password = request.form.get("password")
        user = User.query.filter(User.username == username).first()
        if user:
            return 'username existed.'
        else:
            user = User(username=username, password=password)
            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 render_template("homepage.html")

@app.route("/question/")
def question():
    return render_template("question.html")

if __name__ == '__main__':
     app.run(debug=True)

posted @ 2017-11-24 11:42 JaTae 阅读(161) 评论(0) 收藏举报

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JaTae

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