Question

我正在尝试构建一个与Flask应用程序集成的Dash应用程序。一切似乎都正常，但是当我尝试在Dash应用中显示登录用户时，显示为“无”。

我的应用程序结构如下：

example/
example/
  dashapp/
    static/
      custom-css.css
    templates/
      base.html
      home.html
      login.html
    __init__.py
    app1.py
    forms.py
    models.py
    routes.py
  application.py
  config.py
  users.db

我的Dash应用位于app1.py中。我尝试了几种方法来通过current_user，但没有成功。不过，它在home.html中表现良好。我猜问题出在我的应用程序位于单独的文件中，而不是routes.py中。

这是app.py的代码：

import dash
import dash_html_components as html
from dashapp import application
from flask_login import login_required, current_user


app1 = dash.Dash(__name__, server = application, routes_pathname_prefix = '/app1/', assets_folder = 'static', assets_url_path = '/static')
app1.scripts.config.serve_locally = True
app1.css.config.serve_locally = True

app1.layout = html.Div(
    children = '{}'.format(current_user)
)

for view_func in app1.server.view_functions:
    if view_func.startswith('/app1/'):
        app1.server.view_functions[view_func] = login_required(app1.server.view_functions[view_func])

routes.py代码：

from flask import render_template, flash, redirect, url_for, request
from flask_login import login_user, logout_user, current_user, login_required
from werkzeug.urls import url_parse
from dashapp import application, db
from dashapp.forms import LoginForm
from dashapp.models import User
from dashapp import app1


@application.route('/')
@application.route('/home')
@login_required
def home():
    return render_template('home.html')

@application.route('/login', methods=['GET', 'POST'])
def login():
    if current_user.is_authenticated:
        return redirect(url_for('home'))
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter_by(username=form.username.data).first()
        if user is None or not user.check_password(form.password.data):
            flash('Invalid username or password')
            return redirect(url_for('login'))
        login_user(user, remember=form.remember_me.data)
        next_page = request.args.get('next')
        if not next_page or url_parse(next_page).netloc != '':
            next_page = url_for('home')
        return redirect(next_page)
    return render_template('login.html', form=form)

@application.route('/app1/')

@application.route('/logout')
def logout():
    logout_user()
    return redirect(url_for('login'))

其他脚本几乎是标准的，除非确实需要，否则我不会在问题中包含它们。

请提出如何克服我的问题的建议。谢谢！

Answer 1

我设法在一些帮助下解决了这个问题。万一有人卡住，请参阅下面的更新代码。

添加了session行以将当前用户名存储在routes.py中：

from flask import render_template, flash, redirect, url_for, request, session
from flask_login import login_user, logout_user, current_user, login_required
from werkzeug.urls import url_parse
from dashapp import application, db
from dashapp.forms import LoginForm
from dashapp.models import User
from dashapp import app1

@application.route('/')
@application.route('/home')
@login_required
def home():
    return render_template('home.html')

@application.route('/login', methods=['GET', 'POST'])
def login():
    if current_user.is_authenticated:
        session['username'] = current_user.username
        return redirect(url_for('home'))
    form = LoginForm()
    if form.validate_on_submit():
        session['username'] = form.username.data
        user = User.query.filter_by(username=form.username.data).first()
        if user is None or not user.check_password(form.password.data):
            flash('Invalid username or password')
            return redirect(url_for('login'))
        login_user(user, remember=form.remember_me.data)
        next_page = request.args.get('next')
        if not next_page or url_parse(next_page).netloc != '':
            next_page = url_for('home')
        return redirect(next_page)
    return render_template('login.html', form=form)

@application.route('/logout')
def logout():
    session.pop('username', None)
    logout_user()
    return redirect(url_for('login'))

在session的回调中还有app1.py：

import dash
import dash_html_components as html
from dash.dependencies import Input, Output
from dashapp import application
from flask_login import login_required
from flask import session

app1 = dash.Dash(__name__, server = application, routes_pathname_prefix = '/app1/', assets_folder = 'static', assets_url_path = '/static')
app1.scripts.config.serve_locally = True
app1.css.config.serve_locally = True

app1.layout = html.Div(
    children = [
        html.Div(id='div2'),
        html.Div(id='div3', children = 'xxxx'),
    ],
)

@app1.callback(
    Output('div2', 'children'),
    [Input('div3', 'children')])
def update_intervalCurrentTime(children):
    return session.get('username', None)

for view_func in app1.server.view_functions:
    if view_func.startswith('/app1/'):
        app1.server.view_functions[view_func] = login_required(app1.server.view_functions[view_func])

Answer 2

遇到同样的问题。我想问题是当“应用程序”注册Dash应用程序时，当前用户尚未初始化。不错的解决方法，尽管由于Flask会话只是经过编码而显得有些不安全。

https://github.com/RafaelMiquelino/dash-flask-login/blob/master/app.py-我认为是更强大的解决方案。它检查回调中的current_user并将页面内容用作Input，因此在页面加载时调用回调。如果用户体验不成问题，您还可以跳过视图的保护。

这是我的用法的简化示例：

@app.callback(
    Output('graph-wrapper', 'children'),
    [Input('page-content', 'children')])
def load_graph(input1):
    if current_user.is_authenticated:
        return dcc.Graph() # Dash Graph populated with current_user data from db
    else:
        return ''

将current_user从Flask-Login传递到Plotly Dash应用

2 个答案: