如何在选定的下拉值上应用 dcc 间隔

Question

我希望用户首先从下拉菜单中 select 一个患者 ID，然后 selected id 将使用 dcc.Interval 刷新以获得他当前的实时血压在文本输出中（通过数据库实时）。

但是，我只能得到一个病人的血压，但仍然需要按f5刷新它以获得新的读数压力。如何修改我的第二个回调及其相关函数？

我尝试查找那些教程，但仍然不确定如何将它们融合在一起。谢谢

我的app.layout:

app.layout = html.Div([

                html.Div([dcc.Dropdown(id='dropdown',
                                    options=[{'label': i, 'value': i} for i in x],
                                    value='x',
                                    clearable=False),
                        html.Div(id='table-container')]),

                html.Div([html.Div(id='live-update-text'),
                          dcc.Interval(id='interval-component', interval=2000, n_intervals=0)])

])

各自回调:

#First callback and its function [working as expected]
@app.callback(
    dash.dependencies.Output('dropdown', 'options'),
    [dash.dependencies.Input('dropdown', 'value')])
def get_update_db_dropdown(value):
    #connect to database and then return the results.

#Second callback and its pseudo function; I want this to be self refresh/live updating via dcc interval process
@app.callback(
    Output('live-update-text', 'children'),
    [dash.dependencies.Input('dropdown', 'value')])
def set_display_livedata(value):
    #connect to database and obtain blood pressure where id=value
    return f'selected {id} has {bloodPressure}'

Answer 1

要定期触发回调，您必须添加 Interval 组件作为输入。因此，您的第二个回调应该是

@app.callback(
    Output('live-update-text', 'children'),
    [dash.dependencies.Input('dropdown', 'value'), dash.dependencies.Input('interval-component', 'n_intervals')])
def set_display_livedata(value, n_intervals):
    #connect to database and obtain blood pressure where id=value
    return f'selected {id} has {bloodPressure}'

如何在选定的下拉值上应用 dcc 间隔

how to apply dcc interval on the selected drop down value

python

dashboard

plotly

plotly-dash