npm package: @rlyle1179/react-virtuoso
Description: <img src="https://user-images.githubusercontent.com/13347/101237112-ec4c6000-36de-11eb-936d-4b6b7ec94976.png" width="229" />
Author: Petyo Ivanov
Latest version: 1.0.3

<img src="https://user-images.githubusercontent.com/13347/101237112-ec4c6000-36de-11eb-936d-4b6b7ec94976.png" width="229" />

[![npm version](https://img.shields.io/npm/v/react-virtuoso.svg?style=flat)](//badge.fury.io/js/react-virtuoso)

**React Virtuoso** - the most complete React virtualization rendering list/table/grid family of components.

- Variable sized items out of the box; no manual measurements or hard-coding item heights is necessary;
- [Chat message list UI](https://virtuoso.dev/virtuoso-message-list/) **NEW**;
- [Grouped mode with sticky headers](https://virtuoso.dev/grouped-by-first-letter/);
- [Responsive grid layout](https://virtuoso.dev/grid-responsive-columns/);
- [Table Support](https://virtuoso.dev/hello-table/);
- [Automatic handling of content resize](https://virtuoso.dev/auto-resizing/);
- [Custom Header, Footer, and empty list components](https://virtuoso.dev/customize-structure/);
- [Pinned top items](https://virtuoso.dev/top-items/);
- [Endless scrolling](https://virtuoso.dev/endless-scrolling/), [press to load more](https://virtuoso.dev/press-to-load-more/);
- [Initial top most item index](https://virtuoso.dev/initial-index/);
- [Scroll to index method](https://virtuoso.dev/scroll-to-index/).

For live examples and documentation, check the [documentation website](https://virtuoso.dev).

## Sponsors

If you are using Virtuoso for work, [sponsor it](https://github.com/sponsors/petyosi). Any donation helps a lot with the project development and maintenance.

## Get Started

```sh
npm install react-virtuoso
```

```jsx
import * as React from 'react'
import * as ReactDOM from 'react-dom'
import { Virtuoso } from 'react-virtuoso'

const App = () => {
  return <Virtuoso style={{ height: '400px' }} totalCount={200} itemContent={index => <div>Item {index}</div>} />
}

ReactDOM.render(<App />, document.getElementById('root'))
```

## [Message List](https://virtuoso.dev/virtuoso-message-list/)

The Virtuoso message list component is built specifically for human/chatbot conversations. In addition to the virtualized rendering, the component exposes an imperative data management 
API that gives you the necessary control over the scroll position when older messages are loaded, new messages arrive, and when the user submits a message. The scroll position can update instantly or with a smooth scroll animation.

## [Grouped Mode](https://virtuoso.dev/grouped-by-first-letter/)

The `GroupedVirtuoso` component is a variant of the "flat" `Virtuoso`, with the following differences:

- Instead of `totalCount`, the component exposes `groupCounts: number[]` property, which specifies the amount of items in each group.
  For example, passing `[20, 30]` will render two groups with 20 and 30 items each;
- In addition the `itemContent` property, the component requires an additional `groupContent` property,
  which renders the **group header**. The `groupContent` callback receives the zero-based group index as a parameter.

## [Grid](https://virtuoso.dev/grid-responsive-columns/)

The `VirtuosoGrid` component displays **same sized items** in multiple columns.
The layout and item sizing is controlled through CSS class properties, which allows you to use media queries, min-width, percentage, etc.

## [Table](https://virtuoso.dev/hello-table/)

The `TableVirtuoso` component works just like `Virtuoso`, but with HTML tables.
It supports window scrolling, sticky headers, sticky columns, and works with React Table and MUI Table.

## Works With Your UI Library of Choice

You can customize the markup up to your requirements - check [the Material UI list demo](https://virtuoso.dev/material-ui-endless-scrolling/).
If you need to support reordering, [check the React Sortable HOC example](https://virtuoso.dev/react-sortable-hoc/).

## Documentation and Demos

For in-depth documentation and live examples of the supported features and live demos, check the [documentation website](https://virtuoso.dev).

## Browser support

To support [legacy browsers](https://caniuse.com/resizeobserver), you might have to load a [ResizeObserver Polyfill](https://www.npmjs.com/package/resize-observer-polyfill) before using `react-virtuoso`:

```
import ResizeObserver from 'resize-observer-polyfill'
if (!window.ResizeObserver)
  window.ResizeObserver = ResizeObserver
```

## Author

Petyo Ivanov [@petyosi](//twitter.com/petyosi).

## Contributing

### Fixes and new Features

To run the tests, use `npm run test`.
An end-to-end browser-based test suite is runnable with `npm run e2e`, with the pages being `e2e/*.tsx` and the tests `e2e/*.test.ts`.

A convenient way to debug something is to preview the test cases in the browser.
To do that, run `npm run dev` - it will launch a Ladle server that lets you browse the components in the `examples` folder.

## License

MIT License.