provide built-in support for debouncing

[nite]

Dash would greatly benefit from inbuilt support for debounce. Currently user interaction can easily run into multiple updates or race conditions.

For a simple repro, take the datatable example in https://github.com/plotly/dash-table-experiments/blob/master/usage.py, stick some time.sleeps & logging in update handlers, spin it up and select multiple rows in the grid. You should easily see multiple updates in logs. It's tricky in this example to get a race where an earlier user selection comes in last overriding a later selection, however I have seen this happen in my app.

Debounce is a standard feature in popular javascript util libraries - most js apps feature either lodash or rxjs in their dependencies.

ShinyR also has it: https://shiny.rstudio.com/reference/shiny/latest/debounce.html, and debouncing in some form has been a standard UI practice/feature at least since the days of WPF/Silverlight

There has been some suggestion of modifying/patching datatable to add debounce, however this would require modifying every component and ideally this should be an inbuilt feature of dash core components - eg. if we could wrap a whole component, app or section with a dcc.Debounce() component, then that section would debounce all updates from child components ( debouncing from the clientside, within react)

These could be useful without bringing in lodash or rxjs: https://www.npmjs.com/package/react-debounce-input Debounce function using Ramda.js: https://gist.github.com/tommmyy/daf61103d6022cd23d74c71b0e8adc0d https://www.npmjs.com/package/debounce

[nite]

If this is more appropriate in https://github.com/plotly/dash-core-components and/or any other updates suggestions for this issue, then I'm happy to move/update it.

[chriddyp]

Yeah - I've been writing debounce into some custom components but it would be nice if this was done on the core level so that component authors didn't need to worry about it. I think it could actually live in the app.callback signature (which ties into #200 ) and then implemented in dash-renderer

[nite]

Great - thanks @chriddyp - wish I had some sponsorship powers for you :) happy to collab in other ways though.

[nite]

Also @chriddyp - what custom components have debounce, for reference?

[chriddyp]

what custom components have debounce, for reference?

Unfortunately, none that have been open sourced. Only private components that were built as part of custom engagements with customers.

[nite]

Could you extract a standalone example component by any chance, or update say datatable with it?

[araichev]

Commenting to find this issue later (because Github's subscribe button is unsearchable).