virtualized-list

> A tiny vanilla virtualization library, with DOM diffing

[![npm package][npm-badge]][npm]

Installation
------------

Using npm:

npm install virtualized-list --save

Usage
------------

$3

``js
const rows = ['a', 'b', 'c', 'd'];

const virtualizedList = new VirtualizedList(container, {
height: 500, // The height of the container
rowCount: rows.length,
renderRow: index => {
const element = document.createElement('div');
element.innerHTML = rows[index];

return element;
},
rowHeight: 150,
)};
`

$3


`js
const rows = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const rowHeights = [150, 120, 100, 80, 50, 35, 200, 500, 50, 300];

const virtualizedList = new VirtualizedList(container, {
height: 400,
rowCount: rows.length,
renderRow: (row, index) => {
const element = document.createElement('div');
element.innerHTML = row;

return element;
},
rowHeight: index => rowHeights[index],
estimatedRowHeight: 155,
overscanCount: 5, // Number of rows to render above/below the visible rows.
initialScrollIndex: 8,
onMount: () => {
// Programatically scroll to item index #3 after 2 seconds
setTimeout(() =>
virtualizedList.scrollToIndex(3)
, 2000);
}
)}
`




$3


| Property | Type | Required? | Description |
|:-------------------|:--------------------------|:----------|:----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| height | Number | ✓ | Height of List. This property will determine the number of rendered vs virtualized items |
| rowCount | Number | ✓ | The number of rows you want to render |
| renderRow | Function | ✓ | Responsible for rendering an item given it's index: ({index: number, style: Object}): React.PropTypes.node. The returned element must handle key and style. |
| rowHeight | Number, Array or Function | ✓ | Either a fixed height, an array containing the heights of all the items in your list, or a function that returns the height of an item given its index: (index: number): number |
| initialScrollTop | Number | | The initial scrollTop value (optional) |
| initialIndex | Number | | Initial item index to scroll to (by forcefully scrolling if necessary) |
| overscanCount | Number | | Number of extra buffer items to render above/below the visible items. Tweaking this can help reduce scroll flickering on certain browsers/devices. Defaults to 3 |
| estimatedRowHeight | Number | | Used to estimate the total size of the list before all of its items have actually been measured. The estimated total height is progressively adjusted as items are rendered. |
| onMount | Function | | Callback invoked once the virtual list has mounted. |
| onScroll | Function | | Callback invoked onScroll. function (scrollTop, event)` |
| onRowsRendered | Function | | Callback invoked with information about the range of rows just rendered |

[npm-badge]: https://img.shields.io/npm/v/virtualized-list.svg
[npm]: https://www.npmjs.org/package/virtualized-list