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。

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

app = Flask(__name__)
app.config.from_object(config)
db=SQLAlchemy(app)

db = SQLAlchemy(app)
# 创建用户模型
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)

class Question(db.Model):
    __tablename__ = 'question'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    question = db.Column(db.String(100), nullable=False)
    questionDetail = 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 homepage():
    return render_template("homepage.html")

@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
                sessionpermanent = True
                return redirect(url_for('homepage'))
            else:
                return 'password error'
        else:
            return 'username is not existed'


@app.route("/register/",methods=['GET','POST'])
def register():
    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:
            user = User(username=username, password=password)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for('login'))


@app.context_processor
def mycontext():
    usern = session.get('user')
    if usern:
        return {'username':usern}
    else:
        return {}

@app.route('/logout/')
def logout():
    session.clear()
    return render_template("homepage.html")

def log(func): #参数是函数
    @wraps(func)
    def wrapper(*args, **kwargs): #定义个函数将其返回
        if session.get('user'):
            return func(*args, **kwargs)
        else:
            return redirect(url_for('login'))
    return wrapper #返回一个函数

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

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