Virtualization with Nested Item Rendering

[NotYoojun]

Is your feature request related to a problem? Please describe.

I'm exploring how to implement a tree component that uses nested item rendering while also supporting virtualization for larger datasets.

I found the documentation for both:

• Virtualization
• Nested Rendering

The virtualization example uses a flattened item list (tree.getItems()), which appears to be a different pattern from nested rendering. I'm curious whether combining these two approaches is possible.

Describe the solution you'd like

I'm mainly wondering:

1. Is virtualization technically feasible when using nested item rendering? I imagine it might be tricky since nested structures typically require parent elements to be in the DOM.

2. If it is possible, would you consider adding an example to the docs? No pressure, just thought it might help others with similar questions.

Describe alternatives you've considered

• Flat rendering with indentation: Using the existing virtualization approach with flat rendering. Unfortunately, a flattened DOM structure doesn't work for my particular use case.
• Lazy loading of children: Loading child nodes on expand, though this wouldn't help with large sibling lists.

Additional context

I'm working with file system trees that can have many nodes. The nested DOM structure is a requirement for my project, so I'm trying to figure out if there's a path forward here.

Thanks for the great library, and any thoughts on this would be appreciated!

[lukasbach]

Hi! I have not experimented with combining both, but would assume that this would be rather tricky. Virtualizing non-linear structures is difficult to achieve in general, and HT currently does not provide native support for that, so custom logic to determine how much fillter content to render above the in-viewport content would be required, and also which substructures to render.