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
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)

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

@app.route('/sign_in/',methods=['GET','POST'])
def sign_in():
    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
                session.permanent = True
                return redirect(url_for('home'))
            else:
                return 'password error'
        else:
            return 'username is not existed.'


@app.route('/sign_up/',methods=['GET','POST'])
def sign_up():
    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:
            user1 = User(username=username, password=password)
            db.session.add(user1)
            db.session.commit()
            return redirect(url_for('sign_in'))


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

@app.context_processor
def mycontext():
    username=session.get('user')
    if username:
        return {'username':username}
    else:
        return {}
@app.route('/logout/')
def logout():
    session.clear()
    return redirect(url_for('shouye'))


if __name__ == '__main__':
    app.run(debug=True)
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>
        {% block title %}
        {% endblock %}
        Home</title>
    <link rel="stylesheet" href="{{ url_for('static',filename='css/base css.css')}}">
    <script src="{{ url_for('static',filename='js/base js.js') }}"></script>
     <base target="_blank" />
{% block head %}
{% endblock %}
</head>
<body id="myBody">

<nav class="nav">
    <ul>
         <div>
            {% if username %}
                <li><a href="#"style="margin-right: -10px"><img src="../static/images/b219ebc4b74543a96f1bc1d41d178a82b90114a1.jpg">登录</a></li>
                <li><a href="{{ url_for('logout') }}"><img src="../static/images/b219ebc4b74543a96f1bc1d41d178a82b90114a1.jpg">注销</a></li>
            {% else %}
                <a href="{{ url_for('sign_in') }}" style="margin-right: -10px"><img src="../static/images/b219ebc4b74543a96f1bc1d41d178a82b90114a1.jpg">登录</a>
                <a href="{{ url_for('sign_up') }}" >注册</a>
            {% endif %}
        </div>
        <img id="on_off" onclick="mySwitch()" src="../static/images/bulbon.jpg" width="50px">
        <button style="float: right;margin: 5px auto;border-radius: 5px;height: 30px" type="submit">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>
{% block main %}
{% endblock %}


</body>
</html>
{% extends'base.html' %}
{% block title %}
    Question
{% endblock %}

{% block head %}
    <link rel="stylesheet" href="{{ url_for('static',filename='css/question css.css')}}">
{% endblock %}

{% block main %}
    <div class="question">
    <p class="name">{{ username }}</p>
    <h3>发布问答</h3>
    <form class="biao">
        <div class="form-group">
            <label for="ask">Question</label>
            <br>
            <textarea class="form-control" rows="1" id="ask"></textarea>
        </div>
        <br>
        <div class="form-group">
            <label for="questionDetail">Detail</label>
            <br>
            <textarea class="form-control" rows="8" id="questionDetail"></textarea>
        </div>
        <p></p>
        <input type="checkbox">check me
        <br><br>
        <button type="submit" class="btn-default">发布</button>
    </form>
    </div>
{% endblock %}

 

posted @ 2017-11-24 20:26  blackboardf  阅读(142)  评论(0)    收藏  举报