• 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。

question.html

{% extends'base.html' %}{% block title %}    发布问答{% endblock %}{% block head %}    
         {%  endblock %}{% block main %}
     
    
      
发布问答
    
      
            
       
            
        问题            
        
            
                
       
        
       
        
       
            
        详细内容            
        
            
                
       
        
       
        
       发布        
       返回    
      
     
     
{% endblock %}

py

from flask import Flask,render_template,request,redirect,url_for,sessionfrom flask_sqlalchemy import SQLAlchemyimport configfrom datetime import datetimefrom functools import wrapsapp = Flask(__name__)app.config.from_object(config)db=SQLAlchemy(app)class User(db.Model):    __table__name = '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(50))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('/zhuce/',methods=['GET','POST'])def zhuce():    if request.method =='GET':        return  render_template('zhuce.html')    else:        usern = request.form.get('name')        teln = request.form.get('password')        passw = request.form.get('password1')        user = User.query.filter(User.username==usern).first()        if user:            return 'username existed'        else:            user= User(username=usern,tel=teln,password=passw)            db.session.add(user)            db.session.commit()            return redirect(url_for('login'))@app.route('/login/', methods=['GET','POST'])def login():    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                return redirect(url_for('index'))            else:                return u'password error'        else:            return u'username is not existed'@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'))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'])@loginFirstdef 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'))if __name__ == '__main__':    app.run(debug=True)