Question

在用户在下面的脚本中按下“提交”按钮30秒后，我想让其停止。我将如何去做呢？这是我的代码当前的外观：

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

app = dash.Dash()

app.layout = html.Div([
    dcc.Input(id='my-id', value='initial value', type="text"),
    html.Button('Submit', id='button'),
    html.Div(id='my-div')
])

@app.callback(
    Output(component_id='my-div', component_property='children'),
    [Input('button', 'n_clicks')],
    state=[State(component_id='my-id', component_property='value')]
)
def update_output_div(n_clicks, input_value):
    return 'You\'ve entered "{}" and clicked {} times'.format(input_value, n_clicks)

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

有人知道我如何阻止用户按下按钮30秒钟吗？

先谢谢。

编辑格林尼治标准时间2018年8月15日9:30对stevepastelan的响应：

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

app = dash.Dash()

app.layout = html.Div([
    dcc.Input(id='my-id', value='initial value', type="text"),
    html.Button('Submit', id='button'),
    html.Div([dcc.Interval(
        id='interval-component',
        interval=1 * 3000,  # in milliseconds
        n_intervals=0
)]),
    html.Div(id='my-div')
])

@app.callback(
    Output(component_id='my-div', component_property='children'),
    [Input('button', 'n_clicks')], [Input('interval-component', 'n_intervals')],
    state=[State(component_id='my-id', component_property='value')]
)
def update_output_div(n_clicks,n_intervals, input_value):
    return 'You\'ve entered "{}" and clicked {} times'.format(input_value, n_clicks)

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

编辑15/08/2018 16:22 PM通过编辑后的回叫编写简单脚本，但没有用：

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

app = dash.Dash()

app.layout = html.Div([
    dcc.Input(id='my-id', value='initial value', type="text"),
    html.Button('Submit', id='button'),
    html.Div([dcc.Interval(
        id='interval-component',
        interval=1 * 3000,  # in milliseconds
        n_intervals=0
)]),
    html.Div(id='my-div')
])

@app.callback(
    Output(component_id='my-div', component_property='children'),
    [Input('button', 'n_clicks')], [Input('interval-component', 'n_intervals')],
    state=[State(component_id='my-id', component_property='value')]
)

def update_output_div(n_clicks,n_intervals, input_value):
    return 'You\'ve entered "{}" and clicked {} times'.format(input_value, n_clicks)

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

Answer 1

更新的答案

好的，我设法实现了自己的建议，但这并不简单，但仍然存在怪癖。

复杂因素是：

Dash不允许两个回调以相同的Output为目标
没有很好的方法来跟踪哪个Input或Event触发了您的回调。解决方法通常包括跟踪每个按钮的点击次数（以https://github.com/plotly/dash-html-components/pull/37为例）。
通过disable=True或max_requests=0禁用计时器似乎是永久性的。以这种方式停止计时器后，无法使用disable=False或max_requests=1000重新启动计时器。

问题：

在此解决方案中，update_output_div()被调用两次-但是您可以通过测量到上一次计数的按钮单击次数来区分两者之间的区别，因此可以防止两次提交数据。 / li>
小于100毫秒的超时将不起作用。为了使方法起作用，我不得不拆分延迟计时器，因此我选择了100和(1000 * BUTTON_PRESS_LOCKOUT_SECONDS)-100作为两个计时器持续时间。原则上，您可以将它们平均分配一半。我不知道通过网络工作时使用低超时是否有任何问题（我在本地主机上进行了测试）。

灵感来自：

import json
import datetime

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

BUTTON_PRESS_LOCKOUT_SECONDS = 10  # seconds

app = dash.Dash()
app.config['suppress_callback_exceptions']=True

def serve_layout():
    return html.Div([
        dcc.Input(id='my-id', value='initial value', type="text"),
        html.Button('Submit', id='button'),
        html.Div(
              [
                  dcc.Interval(id='interval-component', disabled=True)
                , dcc.Interval(id='interval-sync-component', disabled=True)
              ]
            , id='interval-container'
        ),
        html.Div("", id='my-div'),
        html.Div(json.dumps({'n_clicks':0, 'n_previous_clicks':0}), id='local_data'),
        html.Div('??', id='button-status'),
    ])

app.layout = serve_layout

# Track button clicks
@app.callback(
    output=Output(component_id='local_data', component_property='children'),
    inputs=[Input('button', 'n_clicks')],
    state=[State('local_data', 'children')],
    events=[Event('interval-sync-component', 'interval')]
)
def track_clicks(n_clicks, local_data_json):
    if n_clicks is None:
        n_clicks = 0

    local_data = json.loads(local_data_json)
    n_previous_clicks = local_data['n_clicks']

    # Update local data with the new click data
    local_data.update(**{'n_clicks': n_clicks, 'n_previous_clicks': n_previous_clicks})
    # local_data.update(**{'n_clicks': n_clicks, 'n_previous_clicks': n_previous_clicks})
    return json.dumps(local_data)


# When the button click count is updated, submit
@app.callback(
    output=Output(component_id='my-div', component_property='children'),
    inputs=[Input('local_data', 'children')],
    state=[State(component_id='my-id', component_property='value'), State('my-div', 'children')]
)
def update_output_div(local_data_json, input_value, current_state):
    local_data = json.loads(local_data_json)
    n_clicks = local_data['n_clicks']
    n_previous_clicks = local_data['n_previous_clicks']

    # Real submit
    if n_clicks > n_previous_clicks:
        return 'You\'ve entered "{}" and clicked {} times ({})'.format(
              input_value
            , n_clicks if n_clicks is not None else 0
            , datetime.datetime.now()
        )

    # Not a real submit, but function is called an extra time as a side effect of the timer nonsense below.
    else:
        return '*' + current_state


# Start (or stop) the timer
@app.callback(
    output=Output('interval-container', 'children'),
    inputs=[Input('local_data', 'children')],
    state=[State('button', 'disabled')],
    events=[Event('interval-component', 'interval')]
)
def start_timer(local_data_json, button_is_disabled):
    local_data = json.loads(local_data_json)
    n_clicks = local_data['n_clicks']
    n_previous_clicks = local_data['n_previous_clicks']

    children=[]

    if n_clicks > n_previous_clicks:
        sync_timer = dcc.Interval(
            id='interval-sync-component',
            interval=100,  # in milliseconds
        )
        children.append(sync_timer)

    if button_is_disabled:
        main_timer = dcc.Interval(
            id='interval-component',
            interval=(1000 * BUTTON_PRESS_LOCKOUT_SECONDS)-100,  # in milliseconds
        )
        children.append(main_timer)

    return children


# Enable the button whenever the timer interval is triggered or disable it when the button is pressed
@app.callback(
    output=Output('button', 'disabled'),
    inputs=[Input('button', 'n_clicks')],
    state=[State('local_data', 'children')],
    events=[Event('interval-component', 'interval')]
)
def toggle_button_disabled_state(n_clicks, local_data_json):
    local_data = json.loads(local_data_json)
    # n_clicks = local_data['n_clicks']
    if n_clicks is None:
        n_clicks = 0
    n_previous_clicks = local_data['n_previous_clicks']

    # We got here via button click, so disable the button
    if n_clicks > n_previous_clicks:
        return True

    # We got here via timer expiration, so enable the button
    else:
        return False  # enable the button

# Report on the button status
@app.callback(
    output=Output('button-status', 'children'),
    inputs=[Input('button', 'disabled')]
)
def update_button_status(disabled):
    if disabled:
        return 'Disabled submit button for {} seconds'.format(BUTTON_PRESS_LOCKOUT_SECONDS)
    else:
        return 'Submit button enabled'


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

原始答案

您可以使用dash_core_components.Interval根据计时器触发要在页面上执行的操作。这里有一些示例：https://dash.plot.ly/live-updates

您可以使用n_intervals = 0初始化时间间隔组件，然后使自己的提交按钮禁用并设置n_intervals = 1。然后在重新启用按钮的间隔上编写一个回调。

在Python + Dash中禁用“提交”按钮30秒钟

1 个答案:

更新的答案

原始答案