README.md

Lustre Virtual List

This is a basic virtual list component for rendering very large lists without performance problems. It renders only a subset of items at a time, based on which items are scrolled into the view.

How To Use

Before you start your lustre app, register the virtual list component.

lustre_virtual_list.register()

In your view function, just call the virtual_list to render a virtual list.

virtual_list(
  items: list.range(1, 100_000),
  render: fn(item: Int) {
    html.div([on_click(ItemClick(item)), class("item")], [
      text("Item #" <> int.to_string(item)),
    ])
  },
  item_height: 24,
  item_count: 40,
  attributes: [class("list")],
),

Note

We recommend only creating virtual lists using the virtual_list function, not using the element directly.

1. items is a list of items that will be passed to your render function.
2. render is a view funciton that receives one item and should return the Element to render.
3. item_height you must specify the height of each item so we can calculate the total size of the list.
4. item_count specify how many items should be rendered at a time.
5. attributes any additional attributes you want to add to the component, for example a class.

Example

You can run the example in the example folder with the following command.

cd example
gleam run -m lustre/dev start

lustre_virtual_list

Installation

If available on Hex this package can be added to your Gleam project:

gleam add lustre_virtual_list

and its documentation can be found at https://hexdocs.pm/lustre_virtual_list.