feat(series): add simple mark formatter

.eslintrc.js

@@ -87,6 +87,7 @@ module.exports = {
     'jsx-a11y/click-events-have-key-events': 1,
     '@typescript-eslint/member-ordering': 1,
     eqeqeq: 1,
+    'unicorn/no-nested-ternary': 0,
 
     /**
      * Standard rules
@@ -249,7 +250,6 @@ module.exports = {
     'unicorn/no-fn-reference-in-iterator': 0,
     'unicorn/prefer-query-selector': 0,
     'unicorn/no-for-loop': 0,
-    'unicorn/no-nested-ternary': 1,
     'unicorn/no-reduce': 0,
     'unicorn/no-useless-undefined': 0,
     'unicorn/prefer-spread': 0,

api/charts.api.md

@@ -263,7 +263,9 @@ export interface BasePointerEvent {
 export type BasicListener = () => undefined | void;
 
 // @public (undocumented)
-export type BasicSeriesSpec = SeriesSpec & SeriesAccessors & SeriesScales;
+export type BasicSeriesSpec = SeriesSpec & SeriesAccessors & SeriesScales & {
+    markFormat?: TickFormatter<number>;
+};
 
 // Warning: (ae-missing-release-tag) "BrushAxis" is exported by the package, but it is missing a release tag (@alpha, @beta, @public, or @internal)
 //
@@ -1485,7 +1487,7 @@ export interface Theme {
 }
 
 // @public (undocumented)
-export type TickFormatter = (value: any, options?: TickFormatterOptions) => string;
+export type TickFormatter<V = any> = (value: V, options?: TickFormatterOptions) => string;
 
 // @public (undocumented)
 export type TickFormatterOptions = {
@@ -1543,11 +1545,12 @@ export type TooltipType = $Values<typeof TooltipType>;
 // @public
 export interface TooltipValue {
     color: Color;
+    formattedMarkValue?: string | null;
     formattedValue: string;
     isHighlighted: boolean;
     isVisible: boolean;
     label: string;
-    markValue?: any;
+    markValue?: number | null;
     seriesIdentifier: SeriesIdentifier;
     value: any;
     valueAccessor?: Accessor;

integration/tests/interactions.test.ts

@@ -278,5 +278,12 @@ describe('Interactions', () => {
         { left: 280, top: 80 },
       );
     });
+
+    it('should use custom mark formatters', async () => {
+      await common.expectChartWithMouseAtUrlToMatchScreenshot(
+        'http://localhost:9001/?path=/story/mixed-charts--mark-size-accessor',
+        { left: 400, top: 80 },
+      );
+    });
   });
 });

src/chart_types/xy_chart/tooltip/tooltip.test.ts

@@ -339,4 +339,43 @@ describe('Tooltip formatting', () => {
     expect(tooltipValue.value).toBe(1);
     expect(tooltipValue.formattedValue).toBe('1');
   });
+
+  describe('markFormat', () => {
+    const markFormat = jest.fn((d) => `${d} number`);
+    const markIndexedGeometry: BarGeometry = {
+      ...indexedGeometry,
+      value: {
+        x: 1,
+        y: 10,
+        accessor: 'y1',
+        mark: 10,
+      },
+    };
+
+    it('should format mark value with markFormat', () => {
+      const tooltipValue = formatTooltip(
+        markIndexedGeometry,
+        {
+          ...SPEC_1,
+          markFormat,
+        },
+        false,
+        false,
+        false,
+        YAXIS_SPEC,
+      );
+      expect(tooltipValue).toBeDefined();
+      expect(tooltipValue.markValue).toBe(10);
+      expect(tooltipValue.formattedMarkValue).toBe('10 number');
+      expect(markFormat).toBeCalledWith(10, undefined);
+    });
+
+    it('should format mark value with defaultTickFormatter', () => {
+      const tooltipValue = formatTooltip(markIndexedGeometry, SPEC_1, false, false, false, YAXIS_SPEC);
+      expect(tooltipValue).toBeDefined();
+      expect(tooltipValue.markValue).toBe(10);
+      expect(tooltipValue.formattedMarkValue).toBe('10');
+      expect(markFormat).not.toBeCalled();
+    });
+  });
 });

src/chart_types/xy_chart/tooltip/tooltip.ts

@@ -21,6 +21,7 @@ import { LegendItemExtraValues } from '../../../commons/legend';
 import { SeriesKey } from '../../../commons/series_id';
 import { TooltipValue } from '../../../specs';
 import { getAccessorFormatLabel } from '../../../utils/accessor';
+import { isDefined } from '../../../utils/commons';
 import { IndexedGeometry, BandedAccessorType } from '../../../utils/geometry';
 import { defaultTickFormatter } from '../utils/axis_utils';
 import { getSeriesName } from '../utils/series';
@@ -83,6 +84,7 @@ export function formatTooltip(
   const isVisible = label === '' ? false : isFiltered;
 
   const value = isHeader ? x : y;
+  const markValue = isHeader || mark === null ? null : mark;
   const tickFormatOptions: TickFormatterOptions | undefined = spec.timeZone ? { timeZone: spec.timeZone } : undefined;
   const tickFormatter =
     (isHeader ? axisSpec?.tickFormat : spec.tickFormat ?? axisSpec?.tickFormat) ?? defaultTickFormatter;
@@ -93,7 +95,12 @@ export function formatTooltip(
     label,
     value,
     formattedValue: tickFormatter(value, tickFormatOptions),
-    markValue: isHeader || mark === null ? null : mark,
+    markValue,
+    ...(isDefined(markValue) && {
+      formattedMarkValue: spec.markFormat
+        ? spec.markFormat(markValue, tickFormatOptions)
+        : defaultTickFormatter(markValue),
+    }),
     color,
     isHighlighted: isHeader ? false : isHighlighted,
     isVisible,

src/chart_types/xy_chart/utils/specs.ts

@@ -422,7 +422,11 @@ export interface SeriesAccessors {
   splitSeriesAccessors?: Accessor[];
   /** An array of fields thats indicates the stack membership */
   stackAccessors?: Accessor[];
-  /** Field name of mark size metric on `Datum` */
+  /**
+   * Field name of mark size metric on `Datum`
+   *
+   * Only used with line/area series
+   */
   markSizeAccessor?: Accessor | AccessorFn;
 }
 
@@ -453,7 +457,16 @@ export interface SeriesScales {
 }
 
 /** @public */
-export type BasicSeriesSpec = SeriesSpec & SeriesAccessors & SeriesScales;
+export type BasicSeriesSpec = SeriesSpec &
+  SeriesAccessors &
+  SeriesScales & {
+    /**
+     * A function called to format every single mark value
+     *
+     * Only used with line/area series
+     */
+    markFormat?: TickFormatter<number>;
+  };
 
 export type SeriesSpecs<S extends BasicSeriesSpec = BasicSeriesSpec> = Array<S>;
 
@@ -661,7 +674,7 @@ export type TickFormatterOptions = {
 };
 
 /** @public */
-export type TickFormatter = (value: any, options?: TickFormatterOptions) => string;
+export type TickFormatter<V = any> = (value: V, options?: TickFormatterOptions) => string;
 
 export const AnnotationTypes = Object.freeze({
   Line: 'line' as const,

src/components/tooltip/tooltip.tsx

@@ -35,7 +35,7 @@ import { getInternalTooltipAnchorPositionSelector } from '../../state/selectors/
 import { getInternalTooltipInfoSelector } from '../../state/selectors/get_internal_tooltip_info';
 import { getSettingsSpecSelector } from '../../state/selectors/get_settings_specs';
 import { getTooltipHeaderFormatterSelector } from '../../state/selectors/get_tooltip_header_formatter';
-import { Rotation } from '../../utils/commons';
+import { Rotation, isDefined } from '../../utils/commons';
 import { TooltipPortal, TooltipPortalSettings, AnchorPosition, Placement } from '../portal';
 import { getTooltipSettings } from './get_tooltip_settings';
 import { TooltipInfo, TooltipAnchorPosition } from './types';
@@ -102,12 +102,23 @@ const TooltipComponent = ({
     <div className="echTooltip__list">
       {values.map(
         (
-          { seriesIdentifier, valueAccessor, label, formattedValue, markValue, color, isHighlighted, isVisible },
+          {
+            seriesIdentifier,
+            valueAccessor,
+            label,
+            markValue,
+            formattedValue,
+            formattedMarkValue,
+            color,
+            isHighlighted,
+            isVisible,
+          },
           index,
         ) => {
           if (!isVisible) {
             return null;
           }
+
           const classes = classNames('echTooltip__item', {
             echTooltip__rowHighlighted: isHighlighted,
           });
@@ -129,7 +140,7 @@ const TooltipComponent = ({
               <div className="echTooltip__item--container">
                 <span className="echTooltip__label">{label}</span>
                 <span className="echTooltip__value">{formattedValue}</span>
-                {markValue && <span className="echTooltip__markValue">&nbsp;({markValue})</span>}
+                {isDefined(markValue) && <span className="echTooltip__markValue">&nbsp;({formattedMarkValue})</span>}
               </div>
             </div>
           );

src/specs/settings.tsx

@@ -111,7 +111,11 @@ export interface TooltipValue {
   /**
    * The mark value
    */
-  markValue?: any;
+  markValue?: number | null;
+  /**
+   * The mark value to display
+   */
+  formattedMarkValue?: string | null;
   /**
    * The color of the graphic mark (by default the color of the series)
    */

stories/mixed/7_marks.tsx

@@ -18,7 +18,8 @@
  */
 
 import { action } from '@storybook/addon-actions';
-import { number, boolean } from '@storybook/addon-knobs';
+import { number, boolean, text } from '@storybook/addon-knobs';
+import numeral from 'numeral';
 import React from 'react';
 
 import { AreaSeries, Axis, Chart, LineSeries, Position, ScaleType, Settings } from '../../src';
@@ -33,7 +34,7 @@ const data1 = new Array(100).fill(0).map((_, x) => ({
 const data2 = new Array(100).fill(0).map((_, x) => ({
   x,
   y: getRandomNumber(0, 100),
-  z: getRandomNumber(0, 50),
+  z: getRandomNumber(0, 50, 4),
 }));
 
 export const Example = () => {
@@ -54,6 +55,7 @@ export const Example = () => {
     max: 100,
     step: 10,
   });
+  const markFormat = text('markFormat', '0.0');
 
   return (
     <Chart className="story-chart">
@@ -81,6 +83,7 @@ export const Example = () => {
         yAccessors={['y']}
         markSizeAccessor="z"
         data={data1.slice(0, size)}
+        markFormat={(d) => `${numeral(d).format(markFormat)}%`}
       />
       <LineSeries
         id="line"
@@ -90,6 +93,7 @@ export const Example = () => {
         yAccessors={['y']}
         markSizeAccessor="z"
         data={data2.slice(0, size)}
+        markFormat={(d) => `${numeral(d).format(markFormat)}%`}
       />
     </Chart>
   );