feat(bar_chart): color/style override accessor (#271)

Allow user to override colors/styles of given BarChart datum based on accessor function prop called StyleAccessor.

BREAKING CHANGE: colorAccessors removed from YBasicSeriesSpec (aka for all series) which had acted similarly to a split accessor.

#216

src/chart_types/xy_chart/domains/y_domain.ts

@@ -16,7 +16,7 @@ export type YDomain = BaseDomain & {
 };
 export type YBasicSeriesSpec = Pick<
   BasicSeriesSpec,
-  'id' | 'seriesType' | 'yScaleType' | 'groupId' | 'stackAccessors' | 'yScaleToDataExtent' | 'colorAccessors'
+  'id' | 'seriesType' | 'yScaleType' | 'groupId' | 'stackAccessors' | 'yScaleToDataExtent' | 'styleAccessor'
 > & { stackAsPercentage?: boolean };
 
 export function mergeYDomain(

src/chart_types/xy_chart/rendering/rendering.test.ts

@@ -1,6 +1,16 @@
 import { DEFAULT_GEOMETRY_STYLES } from '../../../utils/themes/theme_commons';
 import { getSpecId } from '../../../utils/ids';
-import { BarGeometry, getGeometryStyle, isPointOnGeometry, PointGeometry } from './rendering';
+import {
+  BarGeometry,
+  getGeometryStyle,
+  isPointOnGeometry,
+  PointGeometry,
+  getStyleOverrides,
+  GeometryId,
+} from './rendering';
+import { BarSeriesStyle } from '../../../utils/themes/theme';
+import { DataSeriesDatum } from '../utils/series';
+import { RecursivePartial, mergePartial } from '../../../utils/commons';
 
 describe('Rendering utils', () => {
   test('check if point is in geometry', () => {
@@ -168,4 +178,110 @@ describe('Rendering utils', () => {
 
     expect(noHover).toEqual({ opacity: 1 });
   });
+
+  describe('getStyleOverrides', () => {
+    let mockAccessor: jest.Mock;
+
+    const sampleSeriesStyle: BarSeriesStyle = {
+      rect: {
+        opacity: 1,
+      },
+      rectBorder: {
+        visible: true,
+        strokeWidth: 1,
+      },
+      displayValue: {
+        fontSize: 10,
+        fontFamily: 'helvetica',
+        fill: 'blue',
+        padding: 1,
+        offsetX: 1,
+        offsetY: 1,
+      },
+    };
+    const datum: DataSeriesDatum = {
+      x: 1,
+      y1: 2,
+      y0: 3,
+      initialY1: 4,
+      initialY0: 5,
+    };
+    const geometryId: GeometryId = {
+      specId: getSpecId('test'),
+      seriesKey: ['test'],
+    };
+
+    beforeEach(() => {
+      mockAccessor = jest.fn();
+    });
+
+    it('should return input seriesStyle if no styleAccessor is passed', () => {
+      const styleOverrides = getStyleOverrides(datum, geometryId, sampleSeriesStyle);
+
+      expect(styleOverrides).toBe(sampleSeriesStyle);
+    });
+
+    it('should return input seriesStyle if styleAccessor returns null', () => {
+      mockAccessor.mockReturnValue(null);
+      const styleOverrides = getStyleOverrides(datum, geometryId, sampleSeriesStyle, mockAccessor);
+
+      expect(styleOverrides).toBe(sampleSeriesStyle);
+    });
+
+    it('should call styleAccessor with datum and geometryId', () => {
+      getStyleOverrides(datum, geometryId, sampleSeriesStyle, mockAccessor);
+
+      expect(mockAccessor).toBeCalledWith(datum, geometryId);
+    });
+
+    it('should return seriesStyle with updated fill color', () => {
+      const color = 'blue';
+      mockAccessor.mockReturnValue(color);
+      const styleOverrides = getStyleOverrides(datum, geometryId, sampleSeriesStyle, mockAccessor);
+      const expectedStyles: BarSeriesStyle = {
+        ...sampleSeriesStyle,
+        rect: {
+          ...sampleSeriesStyle.rect,
+          fill: color,
+        },
+      };
+      expect(styleOverrides).toEqual(expectedStyles);
+    });
+
+    it('should return a new seriesStyle object with color', () => {
+      mockAccessor.mockReturnValue('blue');
+      const styleOverrides = getStyleOverrides(datum, geometryId, sampleSeriesStyle, mockAccessor);
+
+      expect(styleOverrides).not.toBe(sampleSeriesStyle);
+    });
+
+    it('should return seriesStyle with updated partial style', () => {
+      const partialStyle: RecursivePartial<BarSeriesStyle> = {
+        rect: {
+          fill: 'blue',
+        },
+        rectBorder: {
+          strokeWidth: 10,
+        },
+      };
+      mockAccessor.mockReturnValue(partialStyle);
+      const styleOverrides = getStyleOverrides(datum, geometryId, sampleSeriesStyle, mockAccessor);
+      const expectedStyles = mergePartial(sampleSeriesStyle, partialStyle, {
+        mergeOptionalPartialValues: true,
+      });
+
+      expect(styleOverrides).toEqual(expectedStyles);
+    });
+
+    it('should return a new seriesStyle object with partial styles', () => {
+      mockAccessor.mockReturnValue({
+        rect: {
+          fill: 'blue',
+        },
+      });
+      const styleOverrides = getStyleOverrides(datum, geometryId, sampleSeriesStyle, mockAccessor);
+
+      expect(styleOverrides).not.toBe(sampleSeriesStyle);
+    });
+  });
 });

src/chart_types/xy_chart/rendering/rendering.ts

@@ -1,4 +1,5 @@
 import { area, line } from 'd3-shape';
+
 import { CanvasTextBBoxCalculator } from '../../../utils/bbox/canvas_text_bbox_calculator';
 import {
   AreaSeriesStyle,
@@ -16,7 +17,8 @@ import { CurveType, getCurveFactory } from '../../../utils/curves';
 import { LegendItem } from '../legend/legend';
 import { DataSeriesDatum } from '../utils/series';
 import { belongsToDataSeries } from '../utils/series_utils';
-import { DisplayValueSpec } from '../utils/specs';
+import { DisplayValueSpec, StyleAccessor } from '../utils/specs';
+import { mergePartial } from '../../../utils/commons';
 
 export interface GeometryId {
   specId: SpecId;
@@ -113,6 +115,33 @@ export function mutableIndexedGeometryMapUpsert(
   }
 }
 
+export function getStyleOverrides(
+  datum: DataSeriesDatum,
+  geometryId: GeometryId,
+  seriesStyle: BarSeriesStyle,
+  styleAccessor?: StyleAccessor,
+): BarSeriesStyle {
+  const styleOverride = styleAccessor && styleAccessor(datum, geometryId);
+
+  if (!styleOverride) {
+    return seriesStyle;
+  }
+
+  if (typeof styleOverride === 'string') {
+    return {
+      ...seriesStyle,
+      rect: {
+        ...seriesStyle.rect,
+        fill: styleOverride,
+      },
+    };
+  }
+
+  return mergePartial(seriesStyle, styleOverride, {
+    mergeOptionalPartialValues: true,
+  });
+}
+
 export function renderPoints(
   shift: number,
   dataset: DataSeriesDatum[],
@@ -195,8 +224,9 @@ export function renderBars(
   color: string,
   specId: SpecId,
   seriesKey: any[],
-  seriesStyle: BarSeriesStyle,
+  sharedSeriesStyle: BarSeriesStyle,
   displayValueSettings?: DisplayValueSpec,
+  styleAccessor?: StyleAccessor,
 ): {
   barGeometries: BarGeometry[];
   indexedGeometries: Map<any, IndexedGeometry[]>;
@@ -210,8 +240,8 @@ export function renderBars(
 
   // default padding to 1 for now
   const padding = 1;
-  const fontSize = seriesStyle.displayValue.fontSize;
-  const fontFamily = seriesStyle.displayValue.fontFamily;
+  const fontSize = sharedSeriesStyle.displayValue.fontSize;
+  const fontFamily = sharedSeriesStyle.displayValue.fontFamily;
 
   dataset.forEach((datum) => {
     const { y0, y1, initialY1 } = datum;
@@ -278,6 +308,13 @@ export function renderBars(
           }
         : undefined;
 
+    const geometryId = {
+      specId,
+      seriesKey,
+    };
+
+    const seriesStyle = getStyleOverrides(datum, geometryId, sharedSeriesStyle, styleAccessor);
+
     const barGeometry: BarGeometry = {
       displayValue,
       x,
@@ -290,10 +327,7 @@ export function renderBars(
         y: initialY1,
         accessor: 'y1',
       },
-      geometryId: {
-        specId,
-        seriesKey,
-      },
+      geometryId,
       seriesStyle,
     };
     mutableIndexedGeometryMapUpsert(indexedGeometries, datum.x, barGeometry);

src/chart_types/xy_chart/store/utils.ts

@@ -451,6 +451,7 @@ export function renderGeometries(
         ds.key,
         barSeriesStyle,
         displayValueSettings,
+        spec.styleAccessor,
       );
       barGeometriesIndex = mergeGeometriesIndexes(barGeometriesIndex, renderedBars.indexedGeometries);
       bars.push(...renderedBars.barGeometries);

src/chart_types/xy_chart/utils/series.ts

@@ -92,7 +92,6 @@ export function splitSeries(
   xValues: Set<any>;
 } {
   const { xAccessor, yAccessors, y0Accessors, splitSeriesAccessors = [] } = accessors;
-  const colorAccessors = accessors.colorAccessors ? accessors.colorAccessors : splitSeriesAccessors;
   const isMultipleY = yAccessors && yAccessors.length > 1;
   const series = new Map<string, RawDataSeries>();
   const colorsValues = new Map<string, any[]>();
@@ -102,15 +101,15 @@ export function splitSeries(
     const seriesKey = getAccessorsValues(datum, splitSeriesAccessors);
     if (isMultipleY) {
       yAccessors.forEach((accessor, index) => {
-        const colorValues = getColorValues(datum, colorAccessors, accessor);
+        const colorValues = getColorValues(datum, splitSeriesAccessors, accessor);
         const colorValuesKey = getColorValuesAsString(colorValues, specId);
         colorsValues.set(colorValuesKey, colorValues);
         const cleanedDatum = cleanDatum(datum, xAccessor, accessor, y0Accessors && y0Accessors[index]);
         xValues.add(cleanedDatum.x);
         updateSeriesMap(series, [...seriesKey, accessor], cleanedDatum, specId, colorValuesKey);
       }, {});
     } else {
-      const colorValues = getColorValues(datum, colorAccessors);
+      const colorValues = getColorValues(datum, splitSeriesAccessors);
       const colorValuesKey = getColorValuesAsString(colorValues, specId);
       colorsValues.set(colorValuesKey, colorValues);
       const cleanedDatum = cleanDatum(datum, xAccessor, yAccessors[0], y0Accessors && y0Accessors[0]);
@@ -165,8 +164,8 @@ function getAccessorsValues(datum: Datum, accessors: Accessor[] = []): any[] {
 /**
  * Get the array of values that forms a series key
  */
-function getColorValues(datum: Datum, colorAccessors: Accessor[] = [], yAccessorValue?: any): any[] {
-  const colorValues = getAccessorsValues(datum, colorAccessors);
+function getColorValues(datum: Datum, accessors: Accessor[] = [], yAccessorValue?: any): any[] {
+  const colorValues = getAccessorsValues(datum, accessors);
   if (yAccessorValue) {
     return [...colorValues, yAccessorValue];
   }

src/chart_types/xy_chart/utils/specs.ts

@@ -11,12 +11,16 @@ import { Omit, RecursivePartial } from '../../../utils/commons';
 import { AnnotationId, AxisId, GroupId, SpecId } from '../../../utils/ids';
 import { ScaleContinuousType, ScaleType } from '../../../utils/scales/scales';
 import { CurveType } from '../../../utils/curves';
+import { DataSeriesColorsValues, RawDataSeriesDatum } from './series';
+import { GeometryId } from '../rendering/rendering';
 import { AnnotationTooltipFormatter } from '../annotations/annotation_utils';
-import { DataSeriesColorsValues } from './series';
 
 export type Datum = any;
 export type Rotation = 0 | 90 | -90 | 180;
 export type Rendering = 'canvas' | 'svg';
+export type Color = string;
+export type StyleOverride = RecursivePartial<BarSeriesStyle> | Color | null;
+export type StyleAccessor = (datum: RawDataSeriesDatum, geometryId: GeometryId) => StyleOverride;
 
 interface DomainMinInterval {
   /** Custom minInterval for the domain which will affect data bucket size.
@@ -97,8 +101,8 @@ export interface SeriesAccessors {
   splitSeriesAccessors?: Accessor[];
   /** An array of fields thats indicates the stack membership */
   stackAccessors?: Accessor[];
-  /** An optional array of field name thats indicates the stack membership */
-  colorAccessors?: Accessor[];
+  /** An optional functional accessor to return custom datum color or style */
+  styleAccessor?: StyleAccessor;
 }
 
 export interface SeriesScales {