Tooltip

Enabled by default: hovering shows the nearest node, the node itself is highlighted, and the other series are dimmed.

Modular build

When building with grafit-charts/core, the tooltip is a separate module: register(tooltipModule).

By default the tooltip shows the xField value as the heading and a "series name: value" pair with the series marker. Point series (scatter, bubble) are the exception: both of their axes are measures, so the heading identifies the series (marker + name) and the values come as labelled rows — xName: x, yName: y, plus sizeName: size for bubble. The content is customized via tooltip.renderer on the series:

config.tsdata.ts

import { getData } from './data';
import type { ChartOptions } from 'grafit-charts';

const rub = new Intl.NumberFormat('ru-RU', { style: 'currency', currency: 'RUB', maximumFractionDigits: 0 });

export function createOptions(): ChartOptions {
  return {
    data: getData(),
    title: { text: 'Orders this week' },
    series: [
      {
        type: 'bar',
        xField: 'day',
        yField: 'orders',
        name: 'Orders',
        tooltip: {
          // renderer returns the tooltip structure; datum gives access to the whole data row
          renderer: ({ datum, yValue, color }) => ({
            heading: `${datum.day} — ${yValue} orders`,
            rows: [{ label: 'Revenue', value: rub.format(datum.revenue as number), color }],
          }),
        },
      },
    ],
    legend: { enabled: false },
  };
}

export function getData() {
  return [
    { day: 'Mon', orders: 142, revenue: 388000 },
    { day: 'Tue', orders: 158, revenue: 412000 },
    { day: 'Wed', orders: 149, revenue: 395500 },
    { day: 'Thu', orders: 173, revenue: 460200 },
    { day: 'Fri', orders: 196, revenue: 540800 },
    { day: 'Sat', orders: 224, revenue: 618400 },
    { day: 'Sun', orders: 201, revenue: 552300 },
  ];
}

Modes

mode: 'single' (default) shows the value of the nearest node; mode: 'shared' shows the values of all visible series of the category in a single tooltip; nodes of all series are highlighted and no dimming is applied:

config.tsdata.ts

import { getData } from './data';
import type { ChartOptions } from 'grafit-charts';

export function createOptions(): ChartOptions {
  return {
    data: getData(),
    title: { text: 'Shared tooltip' },
    subtitle: { text: "mode: 'shared' + range: 'nearest' — tooltip from anywhere" },
    series: [
      { type: 'line', xField: 'month', yField: 'plan', name: 'Plan' },
      { type: 'line', xField: 'month', yField: 'fact', name: 'Actual' },
      { type: 'line', xField: 'month', yField: 'forecast', name: 'Forecast', lineDash: [4, 3] },
    ],
    tooltip: { mode: 'shared', range: 'nearest' },
    crosshair: { enabled: true },
  };
}

export function getData() {
  return [
    { month: 'Jan', plan: 120, fact: 134, forecast: 128 },
    { month: 'Feb', plan: 125, fact: 118, forecast: 124 },
    { month: 'Mar', plan: 130, fact: 142, forecast: 136 },
    { month: 'Apr', plan: 135, fact: 129, forecast: 133 },
    { month: 'May', plan: 140, fact: 151, forecast: 146 },
    { month: 'Jun', plan: 145, fact: 148, forecast: 150 },
  ];
}

The mode means the same thing wherever series share a category: a radar carries a measure per series the way a line chart does, so a spoke under the cursor answers for all of them at once — and so do a rose and radial columns, which share their angle axis too.

config.tsdata.ts

import { getData } from './data';
import type { ChartOptions } from 'grafit-charts';

export function createOptions(): ChartOptions {
  return {
    data: getData(),
    title: { text: 'Shared tooltip on a radar' },
    subtitle: { text: "mode: 'shared' — every measure of the spoke under the cursor" },
    series: [
      { type: 'radar-line', angleField: 'metric', radiusField: 'alpha', name: 'Alpha' },
      { type: 'radar-line', angleField: 'metric', radiusField: 'beta', name: 'Beta' },
      { type: 'radar-line', angleField: 'metric', radiusField: 'gamma', name: 'Gamma' },
    ],
    tooltip: { mode: 'shared' },
  };
}

export function getData() {
  return [
    { metric: 'Speed', alpha: 8.1, beta: 6.4, gamma: 4.9 },
    { metric: 'Quality', alpha: 7.4, beta: 8.6, gamma: 6.1 },
    { metric: 'Coverage', alpha: 5.2, beta: 7.1, gamma: 8.4 },
    { metric: 'Uptime', alpha: 9.0, beta: 8.2, gamma: 7.6 },
    { metric: 'Cost', alpha: 4.5, beta: 6.8, gamma: 8.9 },
    { metric: 'Support', alpha: 6.3, beta: 5.4, gamma: 7.2 },
  ];
}

Options (chart-level)

Option	Type	Default	Description
`enabled`	`boolean`	`true`	show the tooltip
`mode`	`'single' \| 'shared'`	`'single'`	one node or the whole category
`position.anchorTo`	`'node' \| 'center' \| 'pointer'`	`'node'`	node edge, node center, or the cursor
`position.xOffset`	`Pixels`	`0`	tooltip offset
`yOffset`	`Pixels`	`0`	tooltip offset
`range`	`Pixels \| 'exact' \| 'nearest'`	`30`	number — radius in px; `'exact'` — only direct hits on a node; `'nearest'` — nearest node from anywhere in the plot area
`container`	`'chart' \| 'body' \| HTMLElement`	`'chart'`	where the tooltip element lives — see Outside the chart
`zIndex`	`number`	`10`; outside the chart — `1000`	CSS z-index of the tooltip element

Outside the chart

The tooltip is a DOM element inside the chart container, kept within its bounds. In a dashboard tile with overflow: hidden, or on a chart a few dozen pixels tall, that is not enough room: the tooltip is clipped or covers the chart itself. container: 'body' moves it to document.body with position: fixed — it is placed next to the node in viewport coordinates and kept within the viewport, so clipping ancestors no longer cut it:

Charts.create({
  container,
  tooltip: { container: 'body' },
  series: [{ type: 'area', xField: 'day', yField: 'visits', marker: { showOn: 'hover' } }],
});

A 48-pixel KPI strip in a frame that clips its content, like a dashboard card. Hover it, then switch the tooltip inside the chart with the button below to see the difference:

config.tsdata.ts

import { getData } from './data';
import type { ChartInstance, ChartOptions } from 'grafit-charts';

const bareAxis = { label: { enabled: false }, line: { enabled: false }, tick: { enabled: false }, gridLine: { enabled: false } };

// A KPI strip in a tile that clips its content, as a dashboard card does. Inside
// the chart the tooltip is held within a strip shorter than itself and cut by the
// tile; in the body it sits by the node whole, reaching past the tile's edges.
export function createOptions(): ChartOptions {
  return {
    data: getData(),
    series: [
      {
        type: 'line',
        xField: 'month',
        yField: 'revenue',
        name: 'Revenue',
        marker: { showOn: 'hover' },
        tooltip: {
          renderer: ({ datum, color }) => ({
            heading: String(datum.month),
            rows: [{ label: 'Revenue', value: `${Number(datum.revenue).toFixed(2)} M`, color }],
          }),
        },
      },
    ],
    axes: [
      { type: 'category', position: 'bottom', paddingOuter: 0, ...bareAxis },
      { type: 'number', position: 'left', nice: false, ...bareAxis },
    ],
    legend: { enabled: false },
    // no floor under the measured size: the strip is exactly as short as its card
    minHeight: 0,
    padding: { top: 6, right: 8, bottom: 6, left: 8 },
    tooltip: { container: 'body', range: 'nearest' },
  };
}

// Buttons under the demo: the same strip with the tooltip in either home.
export const actions = [
  {
    label: 'Tooltip in the body',
    run: (chart: ChartInstance) => void chart.updateDelta({ tooltip: { container: 'body' } }),
  },
  {
    label: 'Tooltip inside the chart',
    run: (chart: ChartInstance) => void chart.updateDelta({ tooltip: { container: 'chart' } }),
  },
];

export function getData() {
  return [
    { month: 'Jan', revenue: 41.2 },
    { month: 'Feb', revenue: 43.8 },
    { month: 'Mar', revenue: 42.5 },
    { month: 'Apr', revenue: 47.1 },
    { month: 'May', revenue: 49.6 },
    { month: 'Jun', revenue: 48.3 },
    { month: 'Jul', revenue: 51.9 },
    { month: 'Aug', revenue: 53.4 },
    { month: 'Sep', revenue: 52.2 },
    { month: 'Oct', revenue: 55.7 },
    { month: 'Nov', revenue: 57.1 },
    { month: 'Dec', revenue: 58.65 },
  ];
}

An element instead of 'body' puts the tooltip into that element — for apps that keep overlays in a layer of their own; it is positioned the same way. Outside the chart:

the tooltip is placed by the node just as inside the chart — right of it and above, flipping where the viewport runs out — only the chart's edges no longer hold it in;
scrolling the page or any scrollable ancestor, and resizing the window, hide the tooltip — the next pointer move shows it again in the right place;
destroy() removes the element along with the chart;
the theme font, size, weight and colors are set on the element itself, since it inherits nothing from the chart container;
position: fixed is relative to the viewport unless an ancestor of the element has transform, filter or contain — keep such styles off the layer you pass.

Appearance

The tooltip container is styled in the same tooltip block:

Option	Type	Default	Description
`background`	`ColorValue`	theme background	background
`borderColor`	`ColorValue`	theme muted color	border color
`borderWidth`	`Pixels`	`1`	border width; `0` removes the border
`borderRadius`	`Pixels`	`6`	corner radius
`shadow`	`string \| false`	`0 2px 8px rgba(0,0,0,.25)`	CSS box-shadow; `false` — no shadow
`padding`	`PaddingValue \| string`	`7px 10px`	inner padding: `8`, `[8, 12]`, `[8, 12, 4, 0]`, `{ top, right, bottom, left }` or a CSS string
`fontSize`	`Pixels`	`12`	font size
`fontFamily`	`string`	`system-ui, sans-serif`	font family
`color`	`ColorValue`	theme foreground	text color

tooltip: {
  background: '#141821',
  color: '#f0f0f0',
  borderColor: '#436ff4',
  borderRadius: 10,
  shadow: false,
},

Series options

series[].tooltip.renderer(params) returns a string (which becomes the heading) or a structure:

renderer: ({ datum, xValue, yValue, seriesName, color }) => ({
  heading: String(xValue),
  rows: [{ label: seriesName, value: String(yValue), color }],
});

params.datum is the entire data row: the tooltip can display fields that are not part of the series.

heading is a string or a { text, color } object; with color a marker matching the row markers is drawn before the heading text. This is how scatter and bubble render their default tooltip — the marker identifies the series rather than any single row:

renderer: ({ datum, xValue, yValue, seriesName, color }) => ({
  heading: { text: String(datum.category), color },
  rows: [
    { label: 'X', value: String(xValue) },
    { label: 'Y', value: String(yValue) },
  ],
});

Highlighting is controlled by the highlight block:

Option	Type	Default	Description
`enabled`	`boolean`	`true`	highlight the node and dim the other series
`dimOpacity`	`Fraction`	`0.8`	opacity of non-highlighted series (1 — no dimming)
`highlight.enabled`	`boolean`	`true`	node highlighting and dimming
`highlight.dimOpacity`	`Fraction`	`0.8`	opacity of non-highlighted series

Tooltip ​

Modes ​

Options (chart-level) ​

Outside the chart ​

Appearance ​

Series options ​

Modes

Options (chart-level)

Outside the chart

Appearance

Series options