Update docs on nested Kino.start_child/1 #452
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| > frame = Kino.Frame.new() | ||
| > {:ok, assign(ctx, frame: frame)} |
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This example is confusing, we create a frame in Kino.JS.Live, but there is no obvious way how we would use that frame (since Kino.JS.Live itself is already about managing JS rendering). If we want a frame to render updates into, as we do in the dbg pipeline, it is actually more natural to create the frame upfront and pass as an argument.
I think it's more about creating kinos like Kino.DataTable.new() and rendering into a provided frame, and it's also more about GenServer, because it's a rare case for Kino.JS.Live.
Co-authored-by: José Valim <[email protected]>
| > that you cannot use functions such as `Kino.DataTable.new/1` in | ||
| > `c:GenServer.init/1`. If you need to do that, you must either | ||
| > create the kinos beforehand and pass in the `GenServer` argument, | ||
| > or create them in `c:GenServer.handle_continue/2`. |
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Ohhh, didn't know it was possible to do that inside handle_continue ! 💡
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@hugobarauna I've been trying to find an example of this. Do you happen to know of an example smartcell that uses handle_continue/2 to start a child kino?
The issue I'm running into is with Kino..SmartCell.Server.validate_init_opts!/2 requiring init options.
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@timgremore I don't think Kino.start_child is relevant for smart cell implementation. The idea is that you use Kino.start_child to start processes in cell code that gets evaluated, so that Livebook knows that it should kill the process before the cell is evaluated again. On the other hand, a smart cell starts and runs in the background, regardless of what gets evaluated (it's just a server process for driving the UI and code generation). If you need the smart cell to start a background process, you can just use start_link.
Do you happen to know of an example smartcell that uses handle_continue/2 to start a child kino?
By "child kino" do you mean like Kino.DataTable.new(...) or similar? Those kinos are generally supposed to be used for cell outputs only. What is your use case? :)
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@jonatanklosko I think I follow the distinction you're explaining. My application involves a :gen_statem implementation that I'm representing in UI. I attempted to start my state machine with something like (this the child kino I referenced above):
Kino.start_child!(%{
start: {MyStateServer, :start_link, []},
id: MyStateServer
})I had thought handle_continue/2 would be an appropriate spot for that call. But I understand your point about that being more suitable for cell code.
Seems start_link is more fitting for what I'm trying to achieve but, if I understand correctly, I'll need something else to start :gen_statem. Is that correct?
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If I understand correctly that you are defining a smart cell and starting the :gen_statem server from the smart cell, you can just do MyStateServer.start_link([]) in the smart cell init and it should be all good.
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That's it! Thank you @jonatanklosko for helping me sort that out
🐈