Multiapp and serialization problem

[brad]

Didn’t have time to look at part 2 of your post. For the first bit, you should use callback context to understand which button was clicked. Gives a lot of additional information, but you’d use something like ctx.triggered[0]['prop_id'].split('.')[0]

See this post for an example:

Help needed: how to check for page first load, to change callback behaviour?

Check out the following. If you place the ctx = dash.callback_context at the start of your callback(s), you can use the info it provides to determine your answer (I believe, since I don’t know how your callbacks are invoked after first-page load). I have implemented a helper function to return True or False if the States are not populated (which would be true on first load) or if inputs are None (which is typical on first page load). Hopefully this spawns an idea on how you can use this to s…