Python Flask-Socketio

Question

我尝试输入发布内容的用户的帖子ID，并在代码行中：comment = Comments（comment = msg，author = current_user._get_current_object（），post_id），coment和author成功输入数据库，但对于post_id值isnull，如何根据用户帖子id从用户帖子输入id

DATABASE

class User(db.Model, UserMixin):
    __searchable__ = ["username"]
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), index=True,unique=True)
    password = db.Column(db.String(64), index=True,unique=True)
    posts = db.relationship('Post',backref='author', lazy='dynamic')
    comments = db.relationship('Comments',backref='author', lazy='dynamic')

    def __repr__(self):
        return self.username

class Post(db.Model):
    __searchable__ = ["body"]
    id = db.Column(db.Integer, primary_key=True)
    body = db.Column(db.String(140))
    timestamp = db.Column(db.DateTime)
    user_id = db.Column(db.Integer,db.ForeignKey('user.id'))
    comments = db.relationship("Comments",backref='post', lazy='dynamic')

    def __repr__(self):
        return self.body

class Comments(db.Model):
    __tablename__ = "comment"
    id = db.Column(db.Integer, primary_key=True)
    user_send_comment = db.Column(db.Integer,db.ForeignKey('user.id'))
    comment = db.Column(db.String(500))
    post_id = db.Column(db.Integer,db.ForeignKey('post.id'))

    def __repr__(self):
        return self.comment

ROUTE

@app.route("/comment/<int:id>", methods=['GET','POST'])
@login_required
def comment(id):
    post = Post.query.get(id)
    form = CommentForm()
    if form.validate_on_submit():
        return redirect(url_for('comment',id=post.id, page=1))
    page = request.args.get('page', 1, type=int)
    if page == -1:
        page = (post.comments.count() - 1) / \
            COMMENTS_PER_PAGE + 1
    pagination = post.comments.paginate(page,per_page=COMMENTS_PER_PAGE, error_out=False)
    comments = pagination.items
    return render_template("comment.html",id=post.id, post=post, comments=comments,pagination=pagination, page=1, form=form)

客户端

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>

<script type="text/javascript"src="//cdnjs.cloudflare.com/ajax/libs/socket.io/1.3.6/socket.io.min.js"></script>

<script type="text/javascript" charset="utf-8">

    $(document).ready(function() {

        namespace = "/comment";

        var socket = io.connect('http://' + document.domain + ':' + location.port + namespace);

        socket.on('connect', function() {

            socket.emit('my event', {

                Data: 'User Has Connected!',

                Username: '{{ current_user.username }}',

                User_ID: '{{ current_user.id }}',

                Post_ID: '{{ post.id }}'

            });

        });

        socket.on('message', function(msg) {

            var postid = '{{ post.id }}'

            $('#log').append('<li>' + '{{ current_user.username }}' + ': ' + msg + '</li>');

        });

        $('#sendbutton').click(function(msg) {

            socket.send($('#myMessages').val());

            return false;

        });

    });

</script>

SERVER

@socketio.on('connect', namespace='/comment')  
def connect():
    emit ("Data", "Username") 

@socketio.on('message', namespace='/comment')
def on_comment(msg):
    print ('Sending Comment: ' + str(msg))
    comment = Comments(comment=msg, author=current_user._get_current_object(), post_id=post.author.username)
    db.session.add(comment)
    db.session.commit()
    send (msg, broadcast=True)  

@socketio.on('myevent', namespace='/comment') 
def on_broadcast(msg):
    print ("Sending Broadcast: " + str(msg))
    emit ('my response', msg, broadcast=True)