完成评论功能

1. 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

@app.route('/comments',methods=["POST"])
@login_first
def comments():
    comment = request.form.get("detail1")
    author_id = Question.query.filter(User.username == session.get('user')).first().id
    ques_id = request.form.get("question_id")
    comm = Comment(detail=comment, author_id=author_id,question_id=ques_id)
    db.session.add(comm)
    db.session.commit()
    return redirect(url_for('detail',question_id=ques_id))

<form action="{{ url_for("comments") }}" method="post">
            <div>

                <textarea  style="width: 400px"  id="xiang" rows="5" name="detail1" placeholder="请输入您的评论"></textarea><br>
                <input style="display: none" value="{{ ques.id }}" name="question_id"/>
                <input  type="submit" value="发送" style="width:45px;height:25px;font-size:15px">
                </div>
        </form>
            <div>
                <h4 >评论:({{ ques.comment|length }})</h4>

<ul class="note">
    {% for foo in ques.comment %}
    <li class="lis">
            <div class="author">
                <a class="nickname" target="_blank" href="{{ url_for("detail",question_id=foo.id) }}">{{ foo.author.username }}说：</a>
                <span class="time">{{ foo.create_time }}</span>
                <p>{{ foo.detail }}</p>
            </div>
    </li>
    {% endfor %}
</ul>