I have a slave dropdown list in my application whose options change based on the value selected in a master dropdown. This part is working as expected. I would also like to add a button which, when the user selects it, causes a default value to be written to the dropdown from a callback (overriding …

Hi @chander Every time a user clicks on the master/top dropdown the callback is fired and therefore it return the dcc.Dropdown() with the value inside it being an empty string because you set value=" ". There are several ways around this. Here is one: from dash.exceptions import PreventUpdate de…

I’ve had the same issue as @chander . @adamschroeder I tried running your example but it didn’t seem to fix the issue as far as I could tell? As far as I can tell from the dash-renderer source , changes to a components props are recorded for persistence purposes when the component calls setProps. Thi…

Hi @adamschroeder , thanks for looking into this. I copied your code for the callback but with this change, the behavior seems a bit wonky. E.g. if you manually select a neighborhood that is not the default, switch to a different city and then back, the default neighborhood for the original shows up…

Thanks, @tcbegley . From your analysis, it would appear that a change in the dash-renderer source is required to make this work correctly. Even though I posted an example featuring a dropdown with single selection, I noticed the issue in my app on a dropdown with multi select and I would like to get…

Hi @chander , I wasn’t really sure what you’re were trying to do with this web app. Therefore, I only solved for what you brought up at your original post: “If you then change the city and come back to the previously selected city, the neighborhood drodown is blank” What is your main goal with t…

Hi @adamschroeder , In my application, I have a dropdown box with multiple selections enabled. The options in this dropdown is controlled by a master dropdown just like the example I posted. The user could physically select values from the dropdown or click some buttons to replace the selections wit…

Now I get you, @chander , I’m not sure. But I would suggest using print(value), print (DEFAULT_NEIGHBORHOODS), print(value) inside your function. That will allow you to see what is captured when the button is triggered or not. And based on that, hopefully you can get the value you need to auto-p…

Dropdown persistence does not work when its value is filled from a callback

Dash Python

chander May 5, 2020, 11:20pm 2

Would appreciate if anyone can help with this. Thanks!

Dash callback Output value clears the persistence of the dcc components

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Dropdown persistence does not work when its value is filled from a callback

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