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• 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
import config
from functools import wraps
from datetime import datetime

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=True)

class Question(db.Model):
    __tablename__ = 'question'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    author_id=db.column(db.Integer,db.ForeignKey('user.id'))
    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=db.relationship('User',backref=db.backref('question'))

db.create_all()    #是否链接成功


# 数据添加
# user=User(username='ma',password='gg')
# db.session.add(user)
# db.session.commit()
#
#
# 数据更新
#
# user = User.query.filter(User.username=='hh').first()
# user.password='gg'
# db.session.commit()
#
#
# 数据查询
# user = User.query.filter(User.username=='ma').first()
# print(user.username,user.password)
#
# 数据删除
# user = User.query.filter(User.username=='ma').first()
# db.session.delete(user)
# db.session.commit()


# session会话连接
# filter()过滤器
# route制定路径和函数之间的关系
# def定义一个变量

@app.route('/')
def switch():
    return render_template('switch.html')


@app.route('/login/', methods=['GET', 'POST'])  # 跳转登陆,methods定义它有两种请求方式
def login():
    if request.method == 'GET':
        return render_template('login.html')
    else:
        username = request.form.get('user')
        password = request.form.get('psw')
        user = User.query.filter(User.username == username).first()  # 判断用户名是否存在
        if user:
           if user.password == password:
               session['user']=username
               session.permanent = True
               return redirect(url_for('switch'))
        else:
            return '用户名不存在'
@app.context_processor
def mycontext():
    username=session.get('user')
    if username:
        return {'username':username}
    else:
        return {}

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'])
# @loginFirst
# def 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,quthor_id=author_id)
#         db.session.add( question )
#         db.session.comit()
#         return (url_for('index'))

@app.route('/register/', methods=['GET', 'POST'])  # 跳转注册,methods定义它有两种请求方式
def register():
    if request.method == 'GET':
        return render_template('register.html')
    else:

        username = request.form.get('user')
        password = request.form.get('psw')
        nickname = request.form.get('nickname')
        user = User.query.filter(User.username == username).first()  # 判断用户名是否存在
        if user:
            return u'该用户已存在'
        else:
            user = User(username=username, password=password, nickname=nickname)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for('login'))

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

@app.route('/wenda/')
def wenda():
    return render_template('wenda.html')


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