完成评论功能

定义评论的视图函数
@app.route('/comment/',methods=['POST'])
def comment()：
读取前端页面数据，保存到数据库中

2用<input type="hidden" 方法获取前端的"question_id" 

3显示评论次数

4要求评论前登录

5尝试实现详情页面下的评论列表显示

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

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

db = SQLAlchemy(app)

#登录的数据库
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))
db.create_all()


#问题页的数据库
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()

class Comment(db.Model):
    __tablename__ = 'comment'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    author_id = db.Column(db.Integer, db.ForeignKey('user.id'))
    question_id=db.Column(db.Integer, db.ForeignKey('question.id'))
    detail = db.Column(db.Text, nullable=False)
    creat_time = db.Column(db.DateTime, default=datetime.now)
    question=db.relationship('Question',backref=db.backref('comments',order_by=creat_time.desc))
    author = db.relationship('User', backref=db.backref('comments'))

db.create_all()






# user=User(username='mis1',password='11111')
# db.session.add(user)
# db.session.commit()




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

# 调用数据库把用户评论放在首页
@app.route('/index/')
def index():
    context = {
            'questions':Question.query.order_by('-creat_time').all()

        }

    return render_template('index.html',**context)

@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('base'))
            else:
                return u'password error'
        else:
            return u'password is not existed'



@app.route('/regist/',methods=['GET','POST'])
def regist():
    if request.method=='GET':
        return render_template('regist.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('login'))


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#发布前登录，python装饰器
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, author_id=author_id)
        db.session.add(question)
        db.session.commit()
        return redirect(url_for('index'))

    # 评论页的详细页
@app.route('/detail/<question_id>')
def detail(question_id):
    context = {
            'comments': Comment.query.all()
        }
    quest = Question.query.filter(Question.id == question_id).first()
    return render_template('detail.html', ques=quest, **context)


#评论功能
@app.route('/comment/',methods=['POST'])
@loginFirst#发布前登录，python装饰器
def comment():
    detail = request.form.get('fabu')
    author_id = User.query.filter(User.username == session.get('user')).first().id
    quest_id =request.form.get('question_id')
    pinglun = Comment(question_id=quest_id,detail=detail, author_id=author_id)
    db.session.add(pinglun)
    db.session.commit()
    return redirect(url_for('detail',question_id=quest_id))





@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)

{% extends 'base.html' %}
{% block title %}
    评论页
{% endblock %}

{% block head %}

     <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" integrity="sha384-PsH8R72JQ3SOdhVi3uxftmaW6Vc51MKb0q5P2rRUpPvrszuE4W1povHYgTpBfshb" crossorigin="anonymous">

{% endblock%}



{% block main %}






    <p>{{username}}context</p>

  <li class="card-body">


<div class="card" style="width:50rem; margin:0 auto">


{#    <li class="list-group-item"style="height:10rem">detail{{ question }}</li>#}
    <ul class="list-group list-group-flush" style="height:100rem">

        <li class="list-group-item">
            <span class="icon" aria-hidden="true"></span>

            <br>

            <h3><img   src="../static/image/yezi.jpg" width="20"
                    height="20">{{ ques.title }}</h3>

            <p>{{ ques.detail }}</p>
        <span class="badge"style="float:right">{{ ques.creat_time}}</span>
           <img   src="../static/image/touxiang.jpg" width="20"
                    height="20">
            <a href="#">{{ ques.author.username}}</a>
        </li>




  <li class="list-group-item"style="height:10rem">

       <form action="{{ url_for('comment') }}" method="post">
        <textarea  rows="2" style="width:40rem"type="password" name="fabu"></textarea>
       <input name="question_id" type="hidden" value="{{ ques.id }}">
<br>
    <input  type="submit" name="commit" value="发布">
       </form>
      <br>
      <h4>评论：({{ ques.comments|length }})</h4>



<ul class="list-group list-group-flush">
{% for foo in ques.comments %}

        <li class="list-group-item">
            <span class="icon" aria-hidden="true"></span>

            <br>

            <h3><img   src="../static/image/yezi.jpg" width="20"
                    height="20"> <a href="{{ url_for('detail',question_id=foo.id) }}">{{ foo.title }}</a></h3>

            <p>{{ foo.detail }}</p>
        <span class="badge"style="float:right">{{ foo.creat_time}}</span>
           <img   src="../static/image/touxiang.jpg" width="20"
                    height="20">
            <a href="#">{{ foo.author.username}}</a>
        </li>

        {% endfor %}
    </ul>


</li>



    </ul>
</div>

</li>
  </div>





{% endblock %}