在 plotly-dash 中的 URL 之間共享數據

Question

我想在 URL 之間共享數據，但隱藏的 div 沒有作為回調 function 中的參數更新，盡管它在頁面中已明確更新。

復制的最小示例：

代碼：

import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output, State

app = dash.Dash(__name__, external_stylesheets=[])

layout = [dcc.Location(id='url', refresh=False)]
layout += [html.Div(id='page-content')]
layout += [html.Div(children="default",
                     id='cache', style={"display": "none"})]
app.layout = html.Div(layout)


@app.callback(
       [Output('page-content', 'children'),
        Output('cache', "children")],
       [Input('url', 'pathname')],
       [State('cache', 'children')],
       )
def route(pathname, data):
    print(data)
    if "/2/" in pathname:
        return html.A(html.H2("1"), href="/1/"), dash.no_update
    elif pathname == "/1/":
        return html.A(html.H2("2"), href="/2/"), "1"
    else:
        return html.A(html.H2("2"), href="/2/"), "1"

if __name__ == '__main__':
    app.run_server(debug=True)

控制台 output（切換頁面幾次后）：

Dash is running on http://127.0.0.1:8050/

 * Serving Flask app "app2" (lazy loading)
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: on
default
default
default
default
default
default
default
default
default
default
default
default
default
default

鉻截圖：

在我的實際應用程序頁面“2”中從數據庫查詢數據，我想在頁面“1”中使用該數據來最小化查詢。

我認為不知何故存在時間問題，但我不明白為什么默認值在被覆蓋后再次設置。

很感謝任何形式的幫助。

提前致謝！

Answer 1

使用商店的解決方法：只需將隱藏的 div 替換為 dcc.Store 與 storage_type session 或本地

import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output, State

app = dash.Dash(__name__, external_stylesheets=[])

layout = [dcc.Location(id='url', refresh=False)]
layout += [html.Div(id='page-content')]
layout += [dcc.Store(id='cache', storage_type='session')]
app.layout = html.Div(layout)


@app.callback(
       [Output('page-content', 'children'),
        Output('cache', "data")],
       [Input('url', 'pathname')],
       [State('cache', 'data')],
       )
def route(pathname, data):
    print(data)
    if "/2/" in pathname:
        return html.A(html.H2("1"), href="/1/"), dash.no_update
    elif pathname == "/1/":
        return html.A(html.H2("2"), href="/2/"), "1"
    else:
        return html.A(html.H2("2"), href="/2/"), "1"

if __name__ == '__main__':
    app.run_server(debug=True)