[BUG] Dropdown clears values on page refresh or tab switch when options are changed

[brianleslie]

Describe your context

python 3.10

dash                      2.4.1 **2.3.1 does not show issue**                                                                                        
dash-bootstrap-components 1.1.0                                                                                         
dash-core-components      2.0.0                                                                                         
dash-daq                  0.5.0                                                                                         
dash-html-components      2.0.0                                                                                         
dash-table                5.0.0 

Describe the bug

Dash dcc dropdown persistence clearing all values when updating options even if returning no_update on value of dropdown

Expected behavior

dash multi selection dropdown should keep values that are still available if options are changed.

I want the inputs to be kept if a tab is changed to and back or on a page refresh (therefore i'm using persistence type local)

another page determines what dropdown options are available on original page

Screenshots

example dropdown setup

layout with a dropdown

            dcc.Dropdown(
                id='my-dropdown',
                options=[],
                value=None,
                persistence=True,
                persistence_type="local",
                multi=True
            ),

@app.callback(
    [Output("my-dropdown", "options"),
     Output("my-dropdown", "value")],
    Input("url", "pathname"),
    [State("my-dropdown", "value")]
)
def load_dropdown(pathname, dropdown_values):
   # some code here that determine what the dropdown options should be and if needed clear options that are no longer available

[brianleslie]

thanks for referencing this @alexcjohnson.

@T4rk1n - any chance you could take a look at fixing this too?

[brianleslie]

sorry didnt mean to close this

[shayan09]

Is there an update on this issue?