登录之后更新导航

  1. 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
  2. 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
  3. 完成注销功能。
    1. 清除session
    2. 跳转

 

base html:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>
        {% block title %}
        {% endblock %}
       啦啦啦</title>

    <link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='css/base.css') }}">
    <script src ="{{ url_for('static',filename='js/base.js') }}"></script>
{% block head %}
{% endblock %}
</head>
<body id="myBody">

<nav>

    <img id="myOnOff" onclick="mySwitch()" 
src="https://www.runoob.com/images/pic_bulbon.gif"　height="20" width="20px">
    <a href="{{ url_for('shouye') }}">首页</a>
    <a href="{{ url_for('wenda') }}">发布问答</a>
    <a href="{{ url_for('shouye') }}">听一听</a>

    <input type="text" name="search">
    <button type="submit">看一看</button>
 

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

</nav>


{% block main %}
{% endblock %}






    <p class="text1">哈哈哈<br>
   by：厚脸皮羊
    </p>

</body>
</html>

 py页面

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('/shouye/')
def shouye():
    return render_template('shouye.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('shouye'))
            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('shouye'))


@app.route('/zhuce/',methods=['GET','POST'])
def zhuce():
    if request.method == 'GET':
        return render_template('zhuce.html')
    else:
        usern = request.form.get('username')
        passw = request.form.get('password')
        user = User.query.filter(User.username == usern).first()
        if user:
            return u'username existed'
        else:
            user1 = User(username=usern, password=passw)
            db.session.add(user1)
            db.session.commit()
            return redirect(url_for('login'))



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



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

 

posted @ 2017-11-24 21:52  201506050096谢阳  阅读(152)  评论(0)  编辑  收藏  举报