Dash MultiPage App Page refresh?

Dash Python
1

I have a multipage Dash WebApp that consists of following pages:

  1. app.py <=from where app is launched
  2. sql.py <=different functions/queries/variables/lists pulling data from SQL
  3. 'page1.py` <=contains a layout for the page, incl. AG Grid
  4. columnDefs_1.py <=contains column definitions for the AG Grid on page1.py and a list a from sql.py
  5. 'page2.py` <=contains a layout for the page, incl. AG Grid
  6. columnDefs_2.py <=contains column definitions for the AG Grid on page2.py and a list b from sql.py

On page1.py and page2.py inside the layout I have the following line, thanks to which the layout is refreshed/activated once a week or when page (app) is refreshed in browser.

dcc.Interval(id='interval_pg1', interval=86400000*7, n_intervals=0),

The problem is that when I physically refresh the webapp in the browser, only page1.py and page2.py are refreshed, i.e. only layouts are refreshed.
The columnDefs_1.py and columnDefs_2.py files are not refreshed, thus, they are not pulling the latest lists from SQL, thus, layout on page1.py and page2.py doesn’t contain latest lists (e.g. dropdown options are not updated).

How do I force columnDefs_1.py and columnDefs_2.py to refresh each time I refresh pages in the browser?

I know I could avoid it if I put all columnDefs inside page1.py and page2.py, but I am trying to do it in a “cleaner” way.

Thanks for help in advance.

2

Hi @mrel

Try making your layouts a function, and putting the part where you pull the latest from SQL inside the layout.

1 Like
3

Hmm, I will see if I can do that.
In the meantime, is it possible to update it via columnState ?

Example:
Code for columnDef1.py

country = ["Germany", "France"]   #in reality this is pulled from SQL via function imported from sql.py

columnDefs = [
    {
        "headerName": "Category",
        "field": "category",
        "filter": "agTextColumnFilter",
        "cellEditor":"agSelectCellEditor",
        "cellEditorParams":{"values":country}
    },
]

Can I update the "cellEditorParams":{"values":country} via a callback from page1.py ?
Could something like this exist perhaps?

@callback(
         Output("table", "columnState"),
         Input("interval", "n_intervals")
 )

 def col_def(interval):
         country_updated  = ["Germany" , "UK", "France", "Netherlands"]    #pulled from SQL via function imported from sql.py
         return [{"colId": "category", "cellEditorParams" : {"values":country_updated}}]