登录之后更新导航

Posted 2020-10-15 J芷璇

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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。
1. 清除session
2. 跳转

python:

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)
    telephone = db.Column(db.String(11), nullable=False)


#db.create_all()

# 增加数据
# user=User(username = \'mis1234\',password = \'111111\',telephone = \'12345678900\')
# db.session.add(user)
# db.session.commit()

# 查询数据

# user=User.query.filter(user.username == \'mis1234\').first()
# print(user.username,user.password)


# 修改数据
# user=User.query.filter(user.username == \'mis1234\').first()
# user.password = \'000000\'
# db.session.commit()

# 删除数据
# user=User.query.filter(user.username == \'mis1234\').first()
# db.session.delete(user)
# db.session.commit()




@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(\'base\'))
            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:
        usern = request.form.get(\'username\')
        telep = request.form.get(\'telephone\')
        passw = request.form.get(\'password\')
        user = User.query.filter(User.username == usern).first()
        if user:
            return \'username existed.\'
        else:
            user1 = User(username=usern, password=passw, telephone=telep)
            db.session.add(user1)  # 数据库操作
            db.session.commit()
            return redirect(url_for(\'login\'))


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


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


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

@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)

html:

<!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 id="myBody">
<nav class="body">
<div style="background-color: floralwhite">
    <form>
        <img id="imgs" src="../static/images/chihuo.jpg">&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp
        <a class="s" href="{{ url_for(\'index\') }}">首页</a>&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp
        <a class="ss" href="{{ url_for(\'question\') }}">下载APP</a>&nbsp&nbsp&nbsp&nbsp
        <input id="sousuo" type="text" name="search" placeholder="请输入搜索内容：">
        <button id="sou" type="submit">查找</button>

        {% if username %}
            <a class="login" href="#">{{ username }}</a>
            <a class="register" href="{{ url_for(\'logout\') }}">注销</a>
        {% else %}
            <a class="login" href="{{ url_for(\'login\') }}">登录</a>
            <a class="register" href="{{ url_for(\'register\') }}">注册</a>
        {% endif %}
        <img id="myOn_Off" onclick="mySwitch()" src="../static/images/taiyang.png" width="50" height="50">
    </form>
</div>
</nav>
{% block main %}
{% endblock %}
<footer>
    <div class="footer_box">
        Copyright@2017-2027 个人版权，版权所有 作者：JZX telephone:0000-1234567 mobile phone:11111111111
    </div>
</footer>
</body>
</html>

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