There are many reasons why one might want to create app object on load, but a very simple example is
to pre-populate Inputs, based on “current data”.
dcc.Input(id='enddate-input', type='Date', value=dt.date.today() )
At the moment, default value of my ‘enddate-input’ will be populated with the date when the webserver process is started, which might be a long time ago.
Similar example: values for dropdowns, that might be linked to categorical values available in a datawarehouse.
As new entries are into DB, I’d like dropdown to automatically pick those.