Hi All

Context
I am creating a small DB analysis tool in LiveBook to explore what we have in our job matching service. Conceptually this is just several relatively simple cells:

1. Select a job opening
2. Select an applicant
3. Display something about applicant

Choose in the previous cell, update in the next cell helps
People at Select something in one LiveBook cell, update list in another cell - #3 by hugobarauna helped me to figure how to use Kino.listen so that “Select an applicant” set was able to react to choices done in the “Select a job opening” step and show the applicant list only for the selected opening.

It works very well except for the first render of the “Select an applicant step”

The problem
By the moment of the very first render of “Select an applicant step”, job opening selector could be clicked multiple times already and I wail to figure how to pass the current value further (except via ssome external storage such :ets , but that sounds like an ugly overkill).

If that was a LiveView, I would just update process assigns from async callback.
What would be the way to make it work in LiveBook? Is there some sort of “current book context” that could be accessed and updated somehow?

Here’s code of what I want to achieve in a very simplified way:

First cell:

# First cell

button = Kino.Control.button("Click")
counter = 0

Kino.listen(button, fn _event ->
  IO.puts("button clicked, counter is #{counter}")

  # Obviously it won't work as it just createa a local variable,
  # it can't update the earlier defined one
  counter = counter + 1
end)

button

Second cell:

# Second cell should be able to set current counter value somehow
IO.puts("Counter as set by the moment of this cell evaluation:#{counter}")

Kino.listen(button, fn _event ->
  IO.puts("Do something with the current counter of #{counter}, maybe increase it as well")
end)