登陆以后更新导航

  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,插入登陆状态判断代码。
    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

 

from flask import Flask,render_template,request,redirect,url_for,session
from flask_sqlalchemy import SQLAlchemy

from datetime import datetime
from functools import wraps
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)
    nickname = db.Column(db.String(20))

class Question(db.Model):
    __table__name = 'question'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    title = db.Column(db.String(100), nullable=False)
    detail = db.Column(db.Text,nullable=False)
    creat_time = db.Column(db.DateTime,default=datetime.now)
    author_id = db.Column(db.Integer, db.ForeignKey('user.id'))
    author = db.relationship('User', backref=db.backref('question'))

#db.create_all()


@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:
        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
                session.permanent = True
                return redirect(url_for('index'))
            else:
                return 'password error'
        else:
            return 'username is not existed.'

@app.route('/regist/',methods=['GET','POST'])
def regist():
    if request.method == 'GET':
        return render_template('regist.html')
    else:
        usern = request.form.get('username')
        nickn = request.form.get('nickname')
        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,nickname=nickn)
            db.session.add(user1)
            db.session.commit()
            return  redirect(url_for('login'))

@app.route('/logout')
def logout():
    session.clear()
    return redirect(url_for('index'))

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

def loginFirst(func):
    @wraps(func)
    def wrapper(*args,**kwargs):
        if session.get('user'):
            return func(*args,**kwargs)
        else:
            return redirect(url_for('login'))
    return wrapper

@app.route('/question/',methods=['GET','POST'])
@loginFirst
def question():
    if request.method == 'GET':
        return render_template('question.html')
    else:
        title = request.form.get('title')
        detail = request.form.get('detail')
        author_id = User.query.filter(User.username == session.get('user')).first().id
        user = User.query.filter(User.username == session.get('user')).first()
        question = Question.query.filter(Question.title == title).first()
        if question:
            return 'question existed.'
        else:
            question = Question(title=title, detail=detail, author_id=author_id)
            question.author = user
            db.session.add(question)
            db.session.commit()
            return redirect(url_for('index'))

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

  #base.htmlcss

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

    {% block head %}{% endblock %}
</head>
<body background="http://p0.so.qhimgs1.com/t01d2e82c8c8f2be36c.jpg" id="myBody">
    <nav class="nav">
        <ul>
            <li><a href="{{ url_for('index') }}"><img src="../static/images/img1.png">首页</a></li>
            <li><a href=""><img src="../static/images/img2.png">下载</a></li>
            <li><a href="{{ url_for('question') }}"><img src="../static/images/img5.png">发布问答</a></li>
            <div>
                {% if username %}
                    <li><a href="#"><img src="../static/images/img3.png">{{ username }}</a></li>
                    <li><a href="{{ url_for('logout') }}"><img src="../static/images/img4.png">注销</a></li>
                {% else %}
                    <li><a href="{{ url_for('login') }}"><img src="../static/images/img3.png">登陆</a></li>
                    <li><a href="{{ url_for('regist') }}"><img src="../static/images/img4.png">注册</a></li>
                {% endif %}
             </div>
            <img class="on_off" id="on_off" onclick="mySwitch()" src="../static/images/pic_bulbon.gif" width="50px">
            <button style="float: right;margin: 5px auto;border-radius: 5px;height: 26px" type="submit"><span class="glyphicon glyphicon-search" aria-hidden="true"></span>搜索</button>
            <input style="float: right;margin: 5px auto;border-radius: 8px;width: 200px;height: 20px;" type="text"name="search" placeholder="输入要搜索的内容">

        </ul>
    </nav>

<div id="bottom">
    <a href="">关于咱们</a>
    <a href="">意见反馈</a>
    <a href="">安全保障</a>
</div>

<div class="copyright">
    <p>Copyright © 2017. Created by <a href="#" target="_blank">suxihong</a></p>
</div>

{% block main %}{% endblock %}
</body>
</html>