在Flask应用中运行Dash应用

Question

我有一个现有的Flask应用程序,我希望有一个到另一个应用程序的路由.更具体地说,第二个应用程序是Plotly Dash应用程序.如何在现有的Flask应用程序中运行我的Dash应用程序？

@app.route('/plotly_dashboard') 
def render_dashboard():
    # go to dash app

我还尝试添加一个到Dash实例的路由,因为它是一个Flask应用程序,但我收到错误:

AttributeError: 'Dash' object has no attribute 'route'

Answer 1

来自文档:

基础Flask应用程序可在以下位置获得app.server.

import dash
app = dash.Dash(__name__)
server = app.server

您还可以将自己的Flask应用实例传递给Dash:

import flask
server = flask.Flask(__name__)
app = dash.Dash(__name__, server=server)

现在您已经拥有了Flask实例,您可以添加所需的任何路由和其他功能.

@server.route('/hello')
def hello():
    return 'Hello, World!'

对于更一般的问题"我如何能够彼此相邻地提供两个Flask实例",假设您最终没有像上面的Dash答案那样使用一个实例,那么您将使用DispatcherMiddleware两个应用程序来安装.

dash_app = Dash(__name__)
flask_app = Flask(__name__)

application = DispatcherMiddleware(flask_app, {'/dash': dash_app.server})

Answer 2

url_base_pathname在您的Dash实例中设置.

app_flask = flask.Flask(__name__)

app_dash = dash.Dash(__name__, server=app_flask, url_base_pathname='/pathname')

现在,您可以在任何您想要的Flask路线下重定向到您的Plotly Dashboard应用程序.

@app_flask.route('/plotly_dashboard') 
def render_dashboard():
    return flask.redirect('/pathname')

Answer 3

对于像我这样懒惰的人来说，这是代码

from dash import Dash
from werkzeug.wsgi import DispatcherMiddleware
import flask
from werkzeug.serving import run_simple
import dash_html_components as html

server = flask.Flask(__name__)
dash_app1 = Dash(__name__, server = server, url_base_pathname='/dashboard' )
dash_app2 = Dash(__name__, server = server, url_base_pathname='/reports')
dash_app1.layout = html.Div([html.H1('Hi there, I am app1 for dashboards')])
dash_app2.layout = html.Div([html.H1('Hi there, I am app2 for reports')])
@server.route('/')
@server.route('/hello')
def hello():
    return 'hello world!'

@server.route('/dashboard')
def render_dashboard():
    return flask.redirect('/dash1')


@server.route('/reports')
def render_reports():
    return flask.redirect('/dash2')

app = DispatcherMiddleware(server, {
    '/dash1': dash_app1.server,
    '/dash2': dash_app2.server
})

run_simple('0.0.0.0', 8080, app, use_reloader=True, use_debugger=True)