Flask - 一条闪光消息不会消失，因为functools.wraps?

Question

我正在构建一个简单的烧瓶网络应用程序，作为哈佛大学CS50 Web编程课程的一部分，以学习Web开发。 我已经成功地实现了用户注册/登录/注销，以及各种消息闪烁以向用户提供反馈。

由于某种原因，"登录成功"闪烁消息在显示后不会消失。 我已经阅读了文档，以及一些有用的帖子，例如这个和这个。 似乎任何带有@login_required装饰器的路由都无法摆脱闪烁的消息。

完整的工作代码在这里：GoodBookBadBook

这是application.py文件：

import os
from flask import Flask, session, request, render_template, url_for, redirect, flash
from flask_session import Session
from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from werkzeug.security import generate_password_hash, check_password_hash
import functools
app = Flask(__name__)
DATABASE_URL = "postgres://xqmbmqkcvpavvs:[e-mail]:5432/dfg72kp1ckutig"
app.config["DATABASE_URL"] = DATABASE_URL
# Configure session to use filesystem
app.config["SESSION_PERMANENT"] = False
app.config["SESSION_TYPE"] = "filesystem"
Session(app)
# Set up database
engine = create_engine(DATABASE_URL)
db = scoped_session(sessionmaker(bind=engine))

def login_required(route_func):
@functools.wraps(route_func)  # returns wrapper as route_func (?).
def wrapper(*args, **kwargs):
print(f"wrapper flashes: {session.get('_flashes', [])}", flush=True)
if "logged_in" in session:
return route_func(*args, **kwargs)
else:
flash("You must log in to use GoodBookBadBook.", category="error")
return redirect(url_for('login'))
return wrapper

@app.route("/")
def index():
print(f"index flashes: {session.get('_flashes', [])}", flush=True)
return render_template("index.html", logged_in=session.get("logged_in", False))

@app.route("/main")
@login_required
def main():
print(f"main flashes: {session.get('_flashes', [])}", flush=True)
return render_template("main.html", logged_in=session.get("logged_in", False))

@app.route("/books")
@login_required  # calls wrapper() with arguments to books().
def books():
print(f"books flashes: {session.get('_flashes', [])}", flush=True)
books = db.execute("SELECT * from Books").fetchall()
return render_template("books.html", books=books, logged_in=session.get("logged_in", False))

@app.route("/books/<int:book_id>")
@login_required  # calls wrapper() with arguments to books().
def book(book_id):
print(f"book flashes: {session.get('_flashes', [])}", flush=True)
book = db.execute("SELECT * from Books WHERE id = :book_id", {"book_id": book_id}).fetchone()
print(f"book() /books/book_id {book}", flush=True)
return render_template("book.html", book=book, logged_in=session.get("logged_in", False))

@app.route("/authors")
@login_required  # calls wrapper() with arguments to authors().
def authors():
print(f"authors flashes: {session.get('_flashes', [])}", flush=True)
books = db.execute("SELECT * from Books").fetchall()
return render_template("authors.html", books=books, logged_in=session.get("logged_in", False))

@app.route("/signup", methods=["GET", "POST"])
def signup():
username = request.form.get("username")
pwd = request.form.get("pwd")
repeat_pwd = request.form.get("repeat_pwd")
print(f"signup flashes: {session.get('_flashes', [])}", flush=True)
if request.method == "POST":
if validate_registration(username, pwd, repeat_pwd):
hash = generate_password_hash(pwd)
db.execute("INSERT INTO Users(Username, Hash) VALUES (:username, :hash)",
{"username": username, "hash": hash})
db.commit()
flash("Registration successful.", category="success")
return redirect(url_for('login'))
return render_template("signup.html")

def validate_registration(username, pwd, repeat_pwd):
existing_user = db.execute("SELECT * from Users WHERE Username = :username",
{"username": username}).fetchone()
print(f"validate_registration flashes: {session.get('_flashes', [])}", flush=True)
if existing_user:
flash("Username unavailable.", category="error")
return False
if len(username) < 3:
flash("Username must be at least 3 characters", category="error")
return False
if pwd != repeat_pwd:
flash("Passwords do not match.", category="error")
return False
if len(pwd) < 3:
flash("Password must be at least 3 characters.", category="error")
return False
return True

@app.route("/login", methods=["GET", "POST"])
def login():
username = request.form.get("username")
pwd = request.form.get("pwd")
print(f"login flashes: {session.get('_flashes', [])}", flush=True)
if request.method == "POST":
existing_user = db.execute("SELECT * from Users WHERE Username = :username",
{"username": username}).fetchone()
if not existing_user:
flash("No user found. Please sign up first.", category="error")
return redirect(url_for('signup'))
if not check_password_hash(existing_user.hash, pwd):
flash("Incorrect password.", category="error")
return
else:
session["logged_in"] = True
flash("Login successful. Thank you for using GoodBookBadBook.", category="success")
return redirect(url_for('main'))
return render_template("login.html")

@app.route("/logout")
def logout():
print(f"logout flashes: {session.get('_flashes', [])}", flush=True)
session.pop("logged_in", None)
flash("You have successfully been logged out. Come back soon!", category="success")
return render_template("logout.html", logged_in=session.get("logged_in", False))

整天都卡在这个上面，任何帮助都是不胜感激的。

编辑：我更新了 git 存储库以删除对超时脚本的所有引用。 我不打算在最终代码中使用超时脚本。

编辑2：这是问题的30秒视频。

Answer 1

只需从signup.html中删除块脚本并main.html

即可

{% block scripts %}
{#  <script type="text/javascript">window.setTimeout("document.getElementById('success-msg').style.display='none';", 2000); </script>#}
{% endblock %}

在Layout.htmlhead标签中添加sucess-msg和error-msg

<head>
<script   type="text/javascript">window.setTimeout("document.getElementById('success-msg').style.display='none';", 2000); </script>
</head>

作为基本 Html 页面layout.html，您需要在该基本文件中添加所有常用脚本，这些脚本可以在其他文件中使用。因此而发生错误(render_template函数，jinja内部缓存，现在不用担心(