# Common chart props

Every chart built with `defineChart` accepts these on top of its own props. HTML components (big-number, callout, ...) do not. All are JSON-serialisable except the callbacks (`onSelect`, `onEvents`, `onReady`) and the function forms of `data`, `transform`, `format` and `option`. Generated from `CommonChartProps` in `packages/insightcharts/src/core/define.tsx`.

| Prop | Type | Description |
|---|---|---|
| `data` | `DataInput` | Rows, CSV text, a URL, `{ url, path }`, an async function, or an Arrow-style table. Omit inside `<InsightData>`. |
| `transform` | `Transform \| Transform[]` | A pipeline of transforms applied before drawing. |
| `title` | `string` | The title. One plain statement of what the data shows, with the number and the period ("Monthly churn fell from 4.2% to 2.1% in 2024"), or a plain label ("Monthly churn, 2024"). One clause, no figures of speech. |
| `subtitle` | `string` | Measure, unit, population, period. |
| `source` | `string` | Data source, shown as "Source: ...". |
| `note` | `string` | Method notes or caveats. |
| `height` | `number \| string` | CSS height of the plot. Default 360. |
| `aspect` | `number` | Width / height. Overrides `height`. |
| `highlight` | `string \| string[]` | The entity (or entities) the title is about. Every other series is drawn in grey. |
| `annotations` | `Annotation[]` | Reference lines, shaded bands and callouts, in data coordinates. |
| `format` | `FormatSpec` | How to print values: `"compact"`, `"percent"`, `"currency:USD"`, `"{value} kg"`, Intl options, or a function. |
| `legend` | `boolean` | Show the legend. Default: shown when there are two or more series. |
| `select` | `boolean \| string` | Make marks clickable to filter. Inside `<InsightData>` the selection filters every other chart. Pass a field name, or `true` to use the chart's category field. |
| `onSelect` | `(values: string[], field: string) => void` | Called with the selected values whenever the selection changes. |
| `option` | `EChartsOption \| ((option: EChartsOption, ctx: BuildContext) => EChartsOption)` | Deep-merged over the generated ECharts option, or a function that receives and returns it. Use it for ECharts settings no prop covers. |
| `theme` | `ThemeInput` | A full theme, `{ light, dark }` partial tokens, or flat tokens applied to both modes. Merged over the surrounding `InsightProvider` theme. |
| `mode` | `ModeInput` | `"auto"` (default) follows the page, `"system"` follows the OS, or force `"light"` / `"dark"`. |
| `renderer` | `RendererInput` | `"auto"` (default) uses SVG for light charts and canvas for heavy ones. |
| `animate` | `boolean` | Set false to disable animation for this chart. Reduced-motion preferences are always respected. |
| `lazy` | `boolean` | Mount the chart only when it scrolls within 200px of the viewport. Default true (from `InsightProvider`). |
| `group` | `string` | Link tooltips with other charts sharing this group id. |
| `exportable` | `boolean \| ExportFormat[]` | Show an export menu: `true` or a list of formats from png, jpeg, svg, pdf, csv, json. |
| `table` | `boolean` | Show a collapsible "View data" table under the chart. |
| `alt` | `string` | Accessible description: the chart type and measures, then the main pattern and the notable values. |
| `id` | `string` | Stable id for this chart's selection in the shared store. |
| `onEvents` | `Record<string, ChartEventHandler>` | ECharts event handlers: `{ click: (params, chart) => {} }`. |
| `onReady` | `(chart: EChartsInstance) => void` | Called with the ECharts instance once it is initialised. |
| `className` | `string` | Class on the figure element. |
| `style` | `CSSProperties` | Inline style on the figure element. |