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)
#db.create_all()

@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('denglu1.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('zhuce.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('home'))


@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)
{% extends'base.html' %}
{% block title %}
    Question
{% endblock %}

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

{% block main %}

    <div class="question">
    <p class="name">欢迎你，{{ 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 %}
<!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')}}">
    <script src="{{ url_for('static',filename='js/base.js') }}"></script>
     <base target="_blank" />
{% block head %}
{% endblock %}
</head>
<body id="myBody">

<nav class="nav">
    <ul>
        <img id="me" src="../static/images/me.gif">
        <a href="{{ url_for('home') }}" style="font-size: 23px ">首页</a>
        <a href="">下载</a>
        <a href="">新闻</a>
        <a href="{{ url_for('question') }}">发布问答</a>
        <a>♥</a>
        <div>
            {% if username %}
                <a href="#" style="margin-right: -10px;color:deepskyblue">{{ username }}</a>
                <a href="{{ url_for('logout') }}" >注销</a>
            {% else %}
                <a href="{{ url_for('sign_in') }}" style="margin-right: -10px">登录</a>
                <a href="{{ url_for('sign_up') }}" >注册</a>
            {% endif %}
        </div>

        <img id="on_off" onclick="mySwitch()" src="../static/images/bulbon.gif" >
        <div>
{#           <button type="submit" ></button>#}
            <input type="image" src="../static/images/search.gif" onmousemove="this.src='../static/images/search.gif'" />
           <input type="text" name="search"PLACEHOLDER="输入要搜索的内容">
        </div>


    </ul>
</nav>
{% block main %}
    <br class="br">
{% endblock %}


<div class="copyright">
    <a href="">联系我们·</a>
    <a href="">加入我们·</a>
    <a href="">品牌与徽标·</a>
    <a href="">帮助中心·</a>
    <a href="">合作伙伴</a>
    <br>
    <p>Copyright &copy; 2017. Created by <a href="#" target="_blank">niu</a></p>
</div>

</body>
</html>

登录成功后登录键发生变化：

登录后发布问答中发生变化：

注销后的发布问答页面：

注销后回到首页：

 

posted @ 2017-11-24 11:27  078刘凯敏  阅读(132)  评论(0)  编辑  收藏  举报