登录之后更新导航

Posted 2020-10-15 Niky7777

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

 

主Python文件：

from flask import Flask, render_template, request, url_for, session, redirect
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)

#创建表格
# db.create_all()

#数据添加方法
# user=User(username=\'mis777789\',password=\'g6666\')
# db.session.add(user)
# db.session.commit()

# 数据的修改方法
# user = User.query.filter(User.username==\'mis777789\').first
# user.password=\'0.0.0.0\'
# db.session.commit()

# 数据的删除方法
# user = User.query.filter(User.username==\'mis777789\').first()
# db.session.delete(user)
# db.session.commit()

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

@app.route(\'/login\',methods=[\'GET\',\'POST\'])
def login():
    if request.method == \'GET\':
        return render_template(\'login.html\')
    else:
        username = request.form.get(\'id\')  # 与html页面名字相同
        password = request.form.get(\'password\')
        user = User.query.filter(User.username == username).first()
        print(username)
        if user:
            if user.password==password:
                 session[\'user\']=username
                 session.permanent=True
                 return redirect(url_for(\'index\'))
            else:
                return \'密码错误\'
        else:
            return \'用户不存在\'


@app.route(\'/regis\',methods=[\'GET\',\'POST\'])
def register():
    if request.method==\'GET\':

        return render_template(\'Zhuce.html\')
    else:

        username=request.form.get(\'zcid\')#与html页面名字相同
        password=request.form.get(\'zcpassword\')
        user=User.query.filter(User.username==username).first()
        if user:
            return \'exit\'
        else:
            user=User(username=username,password=password)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for(\'login\'))

@app.context_processor
def mycontext():
    username=session.get(\'user\')
    if username:
        return {\'username\':username}
    else:
        return {}

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



@app.route(\'/fankui\')
def fankui():
    return render_template("page_fankui.html")

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

父模板中注销和登录：

        <ul class="nav navbar-nav navbar-right">
            {% if username %}
                <li><a href="#"><span class="glyphicon glyphicon-user"></span> {{ username }}</a></li>
                <li><a href={{ url_for("logout") }}><span class="glyphicon glyphicon-log-in"></span> 注销</a></li>
            {% else %}
                <li><a href={{ url_for("register") }}><span class="glyphicon glyphicon-user"></span> 注册</a></li>
                <li><a href={{ url_for("login") }}><span class="glyphicon glyphicon-log-in"></span> 登录</a></li>
            {% endif %}
        </ul>

 

效果图：