@mochart/react

React components for the @mochart/core charting library.

Docs: mochart.org — start with the React guide.

Config and data changes get mochart's staged animations for free — axis expansion, value change (with category and series transitions), axis contraction, and gapless stacked transitions — no extra wiring needed.

Install

npm install @mochart/react @mochart/core react react-dom

React 18 or newer.

The optional stylesheet

If your app uses a global CSS reset (Tailwind's preflight, a normalize.css-style reset), also import the core package's optional stylesheet — it re-asserts the browser defaults the chart's tooltip and message overlays rely on, and never overrides the chart's own styling:

import '@mochart/core/mochart.css';

Usage

DefaultChart is the simplest entry point — give it a raw config and a plain dataset — an array of objects or an object of arrays:

import type { MochartInputConfig } from '@mochart/core';
import { DefaultChart } from '@mochart/react';

const config: MochartInputConfig = {
  title: { text: 'Revenue' },
  categoryAxis: { property: 'month', type: 'string', scale: 'ordinal' },
  seriesDefaults: { renderer: 'bar' },
  series: [{ property: 'revenue', title: 'Revenue' }]
};

const data = [
  { month: 'Jan', revenue: 10 },
  { month: 'Feb', revenue: 20 }
];

export function Revenue() {
  return <DefaultChart config={config} data={data} width={640} height={400} />;
}

Chart is the lower-level component for hosts that manage config enhancement and data providers themselves:

import { enhanceConfig, ArrayOfObjectsDataProvider } from '@mochart/core';
import { Chart } from '@mochart/react';

const mochartConfig = enhanceConfig(config);
const dataProvider = new ArrayOfObjectsDataProvider(data);

<Chart mochartConfig={mochartConfig} dataProvider={dataProvider} width={640} height={400} />

Sizing

width and height are optional. The component renders a container div the chart mounts into; whichever dimension you omit tracks that div's size via ResizeObserver. Size the div with the className/style props and the chart follows it:

<Chart mochartConfig={mochartConfig} dataProvider={dataProvider} style={{ width: '100%', height: 400 }} />

Explicit width/height props win over conflicting style values.

The optional dataTestId prop sets a data-testid attribute on the same container div, for test selectors.

When the data changes

Config and data changes are detected by reference identity: passing the same array or object again — even after mutating it in place — leaves the chart unchanged. Idiomatic React state updates already produce new references:

// ✓ a new array — the chart animates to it
setData(current => [...current, { month: 'Mar', revenue: 30 }]);

// ✗ invisible — same array identity (and no React re-render either)
data.push({ month: 'Mar', revenue: 30 });

The same rule applies to config on DefaultChart and to mochartConfig/dataProvider on Chart. For hosts that do mutate data in place, the ref prop exposes a ChartRef handle whose refresh() re-reads the current data. The built-in providers read live, so any in-place change is seen:

import { useRef } from 'react';
import type { ChartRef } from '@mochart/react';

const chartRef = useRef<ChartRef>(null);

<DefaultChart ref={chartRef} config={config} data={data} />;

data.push({ month: 'Mar', revenue: 30 });
chartRef.current?.refresh();

Props

Both components accept the chart callbacks (onChartClick, onSliceClick, onSeriesClick, onChartMouseEnter, onChartMouseMove, onChartMouseLeave, onTitleClick, onFocus, onSeriesFilter, onSeriesLayoutBoundsChange) and the placeholder components (loadingComponent, errorComponent, noDataComponent, noSizeComponent, noSeriesComponent, configErrorComponent). Each placeholder prop takes a React component that receives the chart context (width, height, error, …) as props and is rendered while the chart is in that state. Placeholders render through a portal in the host component tree, so they read any React context an ancestor provides and follow provider updates — the other bindings reach less, each in its own way. Both components also accept loading and error to force the loading or error state.

Controlled state

Focus and legend filtering are chart-managed by default, but each piece of that state has a matching prop that takes over while it is set (not undefined): focusedCategoryIndex (-1 = none), focusedSeriesId and focusedValueAxisId (null = none), and filteredSeriesIds (a map of series id → true = filtered out). Pass back what onFocus and onSeriesFilter report to keep focus and filtering in sync across several charts; leave a prop undefined to let the chart keep managing that piece itself.

The development export condition

In this repository's manifest, the exports map has a development entry pointing at this package's TypeScript sources; the repo's own dev servers, tests and tsx scripts run the library from source through it. It never reaches npm: publishing goes through pnpm publish, which replaces the map with the dist-only publishConfig.exports, so installed copies of this package always resolve the built dist/.