Python Dash:从回调函数外部更新布局

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

app = dash.Dash(__name__)

app.layout = html.Div([
    dcc.Input(id='input', value='Initial text', type='text'),
    html.Div(id='output')
])

@app.callback(
    Output('output', 'children'),
    [Input('input', 'value')]
)
def update_output(input_value):
    return 'You have entered: {}'.format(input_value)

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

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__)

app.layout = html.Div([
    dcc.Input(id='input', value='Initial text', type='text'),
    html.Div(id='output')
])

@app.callback(
    Output('output', 'children'),
    [Input('input', 'value')],
    [State('input', 'value')]
)
def update_output(input_value, state_value):
    ctx = dash.callback_context

    if ctx.triggered:
        prop_id = ctx.triggered[0]['prop_id'].split('.')[0]

        if prop_id == 'input':
            return 'You have entered: {}'.format(input_value)
    
    return dash.no_update

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