完成評論功能

 

1. 定義評論的視圖函數
   @app.route('/comment/',methods=['POST'])
   def comment()：
   讀取前端頁面數據，保存到數據庫中
   1. 用<input type="hidden" 方法獲取前端的"question_id" 
   2. 顯示評論次數
   3. 要求評論前登陸
   4. 嘗試實現詳情頁面下的評論列表顯示

py主文件代碼

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(100), nullable=False)
    password= db.Column(db.String(500), nullable=False)


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)
    create_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'))

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'))
    create_time = db.Column(db.DateTime, default=datetime.now)
    detail = db.Column(db.Text, nullable=False)
    question = db.relationship('Question',backref=db.backref('comments'))
    author = db.relationship('User',backref=db.backref('comments'))

db.create_all()
# # 增長
# user = User(username = 'zhuyinyin',password='113428164508')
# db.session.add(user)
# db.session.commit()
# 修改
# ser=User.query.filter(User.username =='zhuyinyin').first()
# user.password='123'
# print(user.username,user.password)
# db.session.commit()
#查詢：
# User.query.filter(User.username == 'zhuyinyin').first()
# print(user.username,user.password)

# db.session.commit()
# 修改：
# user.password = '111111'
# db.session.commit()

# 刪除：
# db.session.delete(user)
# db.session.commit()


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

@app.route('/zhuce/',methods=['GET','POST'])
def zhuce():
    if request.method == 'GET':
        return render_template('zhuce.html')
    else:
        username = request.form.get('username')  # 獲取form中的數據
        password = request.form.get('password')  # 獲取form中的數據
        # email = request.form.get('email')  # 獲取form中的數據
        user = User.query.filter(User.username ==username).first()
        if user:
            return'用戶已存在'
        else:
            user = User(username = username,password=password)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for('denglu'))

# @app.route('/denglu/',methods=['GET','POST'])
# def denglu():
#     if request.method=='GET':
#         return render_template('denglu.html')
#     else:
#         username=request.form.get('username')
#         password=request.form.get('password')
#         user=User.query.filter(User.username==username,User.password==password).first()
#         #判斷用戶名是否存在
#         if user:
#             if user.password==password:
#                 return redirect(url_for('shouye'))
#             else:
#                 return '密碼錯誤'
#         else:
#             return '用戶不存在'

#第二種寫法
@app.route('/denglu/',methods=['GET','POST'])
def denglu():
    if request.method=='GET':
        return render_template('denglu.html')
    else:
        username = request.form.get('username')
        password = request.form.get('password')

        user=User.query.filter(User.username==username).first()
        #判斷用戶名是否存在
        if user:
            session['user']=username
            session.permanent=True
            if user.password==password:
                return redirect(url_for('shouye'))
            else:
                return '密碼錯誤'
        else:
            return '此用戶不存在'

@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('shouye'))

def log(func): #參數是函數
    @wraps(func)
    def wrappers(*args,** kwargs): #定義個函數將其返回
        if session.get('user'):
            return func(*args,**kwargs)
        else:
            return redirect(url_for('denglu'))
    return wrappers #返回一個函數


@app.route('/shouye/')
def shouye():
    context = {
        'questions':Question.query.order_by('create_time').all()
    }
    return render_template('shouye.html',**context)

@app.route('/detail/<question_id>') # 和idea的update同樣，將id帶到控制器
def detail(question_id):
    quest = Question.query.filter(Question.id==question_id).first()# 根據id查詢出整條元組記錄，丟進quest
    comments = Comment.query.filter(Comment.question_id==question_id).all()
    return  render_template('detail.html',ques=quest,comments=comments)# 把值quest丟進鍵ques，comments丟進comments在fabuview.html頁面調用

@app.route('/comment/',methods=['POST'])
@log
def comment():
    comment = request.form.get('new_comment')
    ques_id = request.form.get('question_id')
    auth_id=User.query.filter(User.username==session.get('user')).first().id
    comm=Comment(author_id=auth_id,question_id=ques_id,detail=comment)
    db.session.add(comm)
    db.session.commit()
    return redirect(url_for('detail',question_id=ques_id))




@app.route('/wenda/',methods=['GET','POST'])
@log
def wenda():
    if request.method=='GET':
        return render_template('wenda.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)#保存到數據庫
        db.session.commit()#提交
    return redirect(url_for('shouye'))#跳轉

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

詳情頁：

{% extends 'ba.html' %}
{% block title %}
    問答詳情
{% endblock %}
{% block main %}
    <div class="box">
        <h3 href="#">{{ ques.title }}</h3>
        <small> {{ ques.author.username }}<span class="badge" style="margin-left: 75%">{{ ques.create_time }}</span>
        </small>
        <hr>
        <p>{{ ques.detail }}</p>
        <hr>
        <form action="{{ url_for('comment') }}" method="post">
            <div><textarea class="form-control" id="new-comment" rows="3" style="margin-left: 1%" name="new_comment"
                           placeholder="write your comment"></textarea><br></div>
            <input type="hidden" name="question_id" value="{{ ques.id }}">
            <button type="submit">發送</button>
        </form>


        <h4>評論:({{ ques.comments|length }})</h4>

        <ul class="list-unstyled">
            {% for foo in comments %}
                <li class="list-group-item">
                    <a>{{ foo.author.username }}</a>
                    <span class="badge pull-right">{{ foo.create_time }}</span>
                    <p>{{ foo.detail }}</p>
                    <br>
                </li>
            {% endfor %}
        </ul>
    </div>
{% endblock %}