发布功能完成。

• 编写要求登录的装饰器

from functools import wraps

def loginFirst(func): #参数是函数

@wraps(func)

      def wrapper(*args, ** kwargs): #定义个函数将其返回

          #要求登录

          return func(*args, ** kwargs)

      return wrapper #返回一个函数

• 应用装饰器，要求在发布前进行登录，登录后可发布。

@app.route('/question/',methods=['GET','POST'])
@loginFirst
def question():

• 建立发布内容的对象关系映射。

class Question(db.Model):

• 完成发布函数。

保存到数据库。

重定向到首页。

py：

from flask import Flask,render_template,request,redirect,url_for,session
from flask_sqlalchemy import SQLAlchemy
import config
from datetime import datetime
from functools import wraps

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),nullable=False)

class Question(db.Model):
    __tablename__ = '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)
    creatTime = db.Column(db.DateTime,default=datetime.now)
    authorID = 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('/denglu/',methods=['GET','POST'])
def denglu():
    if request.method == 'GET':
        return render_template('denglu.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('/zhuc/',methods=['GET','POST'])
def zhuc():
    if request.method=='GET':
        return render_template('zhuc.html')
    else:
        usern = request.form.get('username')
        passw = request.form.get('password')
        nickn = request.form.get('nickname')
        user=User.query.filter(User.username==usern).first()
        if user:
            return u'username existed.'
        else:
            user = User(username=usern,password=passw,nickname=nickn)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for('denglu'))




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

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

@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('index'))

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

html：

{% extends'base.html' %}
{% block title %}
    wenda
{% endblock %}

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

{% block main %}
    <div class="question">
    <p class="name">欢迎你，{{ username }}</p>
{#    {% if username %}#}
{#        <p class="name">欢迎你，{{ username }}</p>#}
{#    {% else %}#}
{#        <p class="name">欢迎你，请先<a href="{{ url_for('sign_in') }}" >登录</a>或者<a href="{{ url_for('sign_up') }}">注册</a></p>#}
{#    {% endif %}#}
    <h3>发布问答</h3>
    <form action="{{ url_for('label') }}" method="post" >
        <div class="form-group">
            <label for="ask">问题</label>
            <br>
            <textarea class="form-control" rows="1" id="ask" name="title"></textarea>
        </div>
        <br>
        <div class="form-group">
            <label for="questionDetail">详情</label>
            <br>
            <textarea class="form-control" rows="8" id="questionDetail" name="detail"></textarea>
        </div>
        <label>
        <input type="checkbox">check me
        <br><br>
        <button type="submit" class="btn-default">发布</button>
        </label>
    </form>
    </div>
{% endblock %}