Why the element between Shows is removed? about solid

[ryansolid]

Technically it isn't destroyed and created again, it's just detached and reattached. It is the same node reference. This is basically a duplicate of #1734. That being said if I remember properly I checked other algorithms that frameworks use and they were most/all susceptible to this.

I'm going to close this as a duplicate and continue tracking this issue in the other issue.

[pecoram]

Thanks for your reply but I think it is not the same issue.
I'm using the universal renderer in a WebGL Canvas environment and I'd like to understand how can I detect whether the removeNode function is called for an actual node destruction or for the detaching/reattaching sequence you mentioned?

Another question is, why isn't the detach/reattach performed when I have only 2 nodes?

[ryansolid]

The logic happens in the reconciliation so the remove call is just a temporary thing because it doesn't lose the reference internally. The blur event in the other issue was similar because it was due to node being removed and attached again unnecessarily. The shape of the input can change what operations occur.

This does raise the priority of the issue though as you said in the universal renderer scenario you don't know. You probably have to consider a removal a destroy and create unless you manage your own reference counting. And truthfully we don't know either because the DOM takes care of GC itself so we've never needed to track it and I just ported the same algorithm across.

It is possible that any performant algorithm handles all the cases perfectly but this is worth exploring. I went down the rabbit hole of reading the linked issues, and I think someone may have found a diff algorithm that solves at least some portion of these issues. It's definitely worth reviewing.

[chiefcll]

👋 - I need to spend some time researching this further. I originally setup the solid renderer for when removeNode is called it deletes the node and then this issue came up which led me to:
https://github.com/ryansolid/dom-expressions/blob/3796165fef6c757ec073e431244d8a23f96bb3da/packages/dom-expressions/src/universal.js#L210

And I noticed that nodes can be moved via insert + delete. This caused a problem as the node gets deleted but the reference gets passed to insert it somewhere else (and its deleted so no new rendering happens) - My current hunch is should replaceNode be something universal targets implement? Then I can deal with how that gets done and not delete the node if I'm just changing parents. Implementation I have at the moment: https://github.com/lightning-js/solid/blob/main/src/core/universal/lightning.ts#L90

Like I said I need to dive into the code a bit more to provide further context for you. Thanks!