hightable
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A dynamic windowed scrolling table component for react
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# HighTable
[](https://www.npmjs.com/package/hightable)
[](https://www.npmjs.com/package/hightable)
[](https://github.com/hyparam/hightable/actions)
[](https://opensource.org/licenses/MIT)
[](https://www.npmjs.com/package/hightable?activeTab=dependencies)
HighTable is a virtualized table component for React, designed to efficiently display large datasets in the browser. It loads and renders only the rows necessary for the current viewport, enabling smooth scrolling and performance even with millions of rows. HighTable supports asynchronous data fetching, dynamic loading, and optional column sorting.
## Features
- **Virtualized Scrolling**: Efficiently renders only the visible rows, optimizing performance for large datasets.
- **Asynchronous Data Loading**: Fetches data on-demand as the user scrolls, supporting datasets of any size.
- **Column Sorting**: Optional support for sorting data by columns.
- **Column Resizing**: Allows for resizing columns to fit the available space and auto-sizing.
- **Row Selection**: Supports selecting multiple rows using shift+click.
- **Event Handling**: Supports double-click events on cells.
- **Loading Placeholder**: Displays animated loading indicator per-cell.
## Demo
Live table demo: [https://hyparam.github.io/demos/hightable/](https://hyparam.github.io/demos/hightable/). See the [source code](https://github.com/hyparam/demos/tree/master/hightable).
## Installation
Ensure you have React set up in your project. Install the HighTable package via npm:
```sh
npm i hightable
```
## Data Model
HighTable uses a data model called `DataFrame`, which defines how data is fetched and structured. The `DataFrame` object should have the following properties:
- `header`: An array of strings representing the column names.
- `numRows`: The total number of rows in the dataset.
- `getRowNumber`: A function that returns the row number for a given row index. If not resolved yet, it returns undefined.
- `getCell`: A function that returns the value of a cell at a specific row and column. If not resolved yet, it returns undefined.
- `eventTarget`: An optional event target which must dispatch the event `resolve` when a cell or row number is resolved. This can be used to trigger re-renders or other side effects.
- `fetch`: An optional asynchronous function that fetches cells and row numbers, for a range of rows and columns. It should only fetch the missing data, and once the data is fetched, `getRowNumber` and `getCell` should return the resolved values. It is responsible for dispaching the `resolve` event (once or multiple times) on the `eventTarget` when the data is ready.
## Usage
Here's a basic example of how to use HighTable in your React application:
```jsx
import HighTable from 'hightable'
const eventTarget = new EventTarget()
const cache = new Map()
const store = (cells) => {
for (const [col, values] of Object.entries(cells)) {
if (!cache.has(col)) cache.set(col, new Map())
for (const [row, value] of Object.entries(values)) {
cache.get(col).set(Number(row), ({value}))
}
}
}
const dataframe = {
columnDescriptors: [{name: 'ID'}, {name: 'Name'}, {name: 'Email'}],
numRows: 1000000,
getRowNumber: ({ row }) => ({ value: rowIndex }),
getCell: ({ row, col }) => cache.get(col).get(row),
eventTarget,
async fetch({row, column}) {
// fetch cell data from your data source here
const cells = await fetchCellData(row, col)
// store the fetched data in the cache
store(cells)
// dispatch the resolve event to notify the table that the data is ready
eventTarget.dispatchEvent(new CustomEvent('resolve'))
}
}
function App() {
return (
<HighTable
data={dataframe}
onError={console.error}
/>
)
}
```
## Props
HighTable accepts the following props:
```typescript
interface TableProps {
data: DataFrame // data provider for the table
focus?: boolean // focus table on mount? (default true)
onDoubleClickCell?: (col: number, row: number) => void // double-click handler
onError?: (error: Error) => void // error handler
orderBy?: OrderBy; // order by column (if defined, the component order is controlled by the parent)
onOrderByChange?: (orderBy: OrderBy) => void; // orderBy change handler
selection?: Selection; // selection state (if defined, the component selection is controlled by the parent)
onSelectionChange?: (selection: Selection) => void; // selection change handler
columnConfiguration?: Record<string, ColumnConfig>; // allows for additional configuration of columns
onColumnsVisibilityChange?: (columnVisibilityStates: MaybeHiddenColumn[]) => void; // columns visibility change handler
}
```
DataFrame is defined as:
```typescript
interface DataFrame<M extends Record<string, any>, C extends Record<string, any>> {
columnDescriptors: ColumnDescriptor<C>[];
numRows: number;
metadata?: M; // optional metadata for the DataFrame - use the generic type for increased type safety
// rows are 0-indexed, excludes the header, end is exclusive
// if orderBy is defined, start and end are applied on the sorted rows
getRowNumber({ row, orderBy }: { row: number, orderBy?: OrderBy }): ResolvedValue<number> | undefined
getCell({ row, column, orderBy }: {row: number, column: string, orderBy?: OrderBy}): ResolvedValue | undefined
fetch?: ({ rowStart, rowEnd, columns, orderBy, signal }: { rowStart: number, rowEnd: number, columns?: string[], orderBy?: OrderBy, signal?: AbortSignal }) => Promise<void>
eventTarget?: EventTarget;
}
```
ColumnDescriptor is defined as:
```typescript
interface ColumnDescriptor<C extends Record<string, any>> {
name: string; // column name
sortable?: boolean; // is the column sortable? Defaults to false
metadata?: C; // custom metadata extendable by the user
}
```
ResolvedValue is defined as:
```typescript
type ResolvedValue<T = any> = {
value: T; // resolved value
}
```
OrderBy is defined as:
```typescript
interface OrderBy {
column: string // column name
direction?: "ascending" // sort direction - only ascending is supported
}
```
Selection is defined as:
```typescript
interface Selection {
ranges: Array<{
start: number // inclusive lower limit, positive integer
end: number // exclusive upper limit, positive integer, strictly greater than start (no zero-length ranges).
}>; // the rows selection is an array of row index ranges (0-based). The values are indexes of the virtual table (sorted rows), and thus depend on the order.
anchor?: number // anchor row used as a reference for shift+click selection. It's a virtual table index (sorted), and thus depends on the order.
}
```
ColumnConfig is defined as:
```typescript
interface ColumnConfig {
headerComponent?: React.ReactNode; // allows overriding column header cell with custom component
minWidth?: number; // overrides the global column min width, useful for components with ui elements
}
```
## Array to DataFrame
HighTable includes a helper function to convert an array of objects to a DataFrame object. The function accepts an array of objects and assume that all the objects share the same keys. The dataframe is not sortable, see `sortableDataFrame` for that.
```javascript
import { arrayDataFrame } from 'hightable'
const data = [
{ id: 1, name: 'Alice' },
{ id: 2, name: 'Bob' },
]
const dataframe = arrayDataFrame(data)
```
## Sortable DataFrame
If your data source supports sorting, set the sortable property to true in your DataFrame object. When sorting is enabled, the rows function will receive an additional orderBy parameter, which represents the column name to sort by.
Ensure your rows function handles the orderBy parameter appropriately to return sorted data.
HighTable includes a helper function to transform a dataframe to a sorted dataframe:
```javascript
import { sortedDataFrame } from 'hightable'
const sortableDf = sortableDataFrame(df)
```
## Legacy DataFrame format
The legacy DataFrame format can still be used, but it is not recommended for new projects. It has the following structure:
```ts
export interface DataFrameV1 {
header: string[]
numRows: number
rows({ start, end, orderBy }: { start: number, end: number, orderBy?: OrderBy }): AsyncRow[]
getColumn?: GetColumn
sortable?: boolean
}
```
HighTable provides a helper function to convert the legacy DataFrame format to the new format:
```javascript
import { convertV1ToDataFrame } from 'hightable/helpers/dataframe/legacy/index.js'
const legacyDataFrame = {
header: ['ID', 'Name', 'Email'],
numRows: 1000000,
rows({ start, end }) {
// fetch rows from your data source here
return fetchRowsFromServer(start, end)
}
}
const dataframe = convertV1ToDataFrame(legacyDataFrame)
```
## Styling
HighTable includes basic CSS styling to make the table functional. You can customize the appearance of the table using CSS.
## Structure of the code
The code is structured as follows:
- `src/`: Source code
- `components/`: React components
- `helpers/`: Helper functions, specific for HighTable
- `hooks/`: Custom hooks
- `utils/`: Generic utility functions
- `test/`: Unit tests (follows the same structure as `src/`)