• 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。

{% extends 'basic.html' %}{% block title %}登录{% endblock %}{% block head %}    
         
         
         {% endblock %}{% block question %}
     
      
    
       
发布问答
            
       
            
        问题            
        
            
                
       
        
       
        
       
            
        详细内容            
        
            
                
       
        
       
        
       发布        
       返回     
      
     
    {% endblock %}

from flask_sqlalchemy import SQLAlchemyimport configfrom flask import Flask,render_template,request,redirect, url_for,sessionfrom functools import wrapsfrom datetime import datetimeapp = 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):     __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)     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 u'password error'        else:            return u'password is not existed'@app.route('/rege/',methods=['GET','POST'])def rege():    if request.method =='GET':        return render_template('rege.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 'username.existed.'        else:            user1 = User(username=usern,password=passw,nickname = nickn)            db.session.add(user1)            db.session.commit()            return redirect(url_for('login'))def loginFrist(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'])@loginFristdef 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        question = Question(title=title, detail=detail, author_id=author_id)        db.session.add(question)        db.session.commit()        return redirect(url_for('index'))@app.context_processordef 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)