feat(Bar/Column/ComposedChart): add stack aggregate total labels and tooltip support

.storybook/preview-head.html

@@ -191,6 +191,11 @@
     align-items: flex-start;
   }
 
+  /* Stacked chart tooltip total row */
+  .stackedTooltipWithTotal .recharts-tooltip-item:last-child {
+    font-weight: bold;
+  }
+
   /* TODO remove this workaround as soon as https://github.com/storybookjs/storybook/issues/20497 is fixed */
   .docs-story > div > div[scale] {
     min-height: 20px;

cypress/support/utils.tsx

@@ -100,3 +100,26 @@ export function testChartLegendConfig(Component, props) {
     cy.findAllByTestId('catval').should('be.visible');
   });
 }
+
+export function testStackAggregateTotals(Component, props) {
+  it('showStackAggregateTotals', () => {
+    const { dataset, measures } = props;
+    const stackAccessors = measures.filter((measure) => measure.stackId != null).map((measure) => measure.accessor);
+    const expectedTotals: number[] = dataset.map((entry) =>
+      stackAccessors.reduce((sum, accessor) => sum + (Number(entry[accessor]) || 0), 0),
+    );
+
+    cy.mount(<Component {...props} noAnimation chartConfig={{ showStackAggregateTotals: true }} />);
+
+    expectedTotals.forEach((total) => {
+      cy.get('.recharts-label').contains(total).closest('text').should('have.attr', 'font-weight', 'bold');
+    });
+
+    // tooltip
+    cy.get('.recharts-wrapper').trigger('mousemove', 'center', { force: true });
+    cy.get('.recharts-tooltip-item').last().should('contain.text', 'Total : 560').and('have.css', 'font-weight', '700');
+
+    cy.mount(<Component {...props} noAnimation chartConfig={{ showStackAggregateTotals: false }} />);
+    cy.get('.recharts-label').should('not.exist');
+  });
+}

packages/charts/src/components/BarChart/BarChart.cy.tsx

@@ -1,6 +1,11 @@
 import { complexDataSet } from '../../resources/DemoProps.js';
 import { BarChart } from './index.js';
-import { cypressPassThroughTestsFactory, testChartLegendConfig, testChartZoomingTool } from '@/cypress/support/utils';
+import {
+  cypressPassThroughTestsFactory,
+  testChartLegendConfig,
+  testChartZoomingTool,
+  testStackAggregateTotals,
+} from '@/cypress/support/utils';
 
 const dimensions = [
   {
@@ -93,4 +98,13 @@ describe('BarChart', () => {
   testChartZoomingTool(BarChart, { dataset: complexDataSet, dimensions, measures });
 
   cypressPassThroughTestsFactory(BarChart, { dimensions: [], measures: [] });
+
+  testStackAggregateTotals(BarChart, {
+    dataset: complexDataSet.slice(0, 3),
+    dimensions,
+    measures: [
+      { accessor: 'users', stackId: 'A', label: 'Users' },
+      { accessor: 'sessions', stackId: 'A', label: 'Active Sessions' },
+    ],
+  });
 });

packages/charts/src/components/BarChart/BarChart.mdx

@@ -3,6 +3,8 @@ import { Canvas, Meta } from '@storybook/addon-docs/blocks';
 import TooltipStory from '../../resources/TooltipConfig.mdx';
 import LegendStory from '../../resources/LegendConfig.mdx';
 import NormalizedStackedChartStory from '../../resources/NormalizedStackedChart.mdx';
+import StackAggregateTotalsStory from '../../resources/StackAggregateTotals.mdx';
+import CustomTooltipTotalStory from '../../resources/CustomTooltipTotal.mdx';
 import * as ComponentStories from './BarChart.stories';
 
 <Meta of={ComponentStories} />
@@ -67,6 +69,16 @@ You can set a reference line to any value by using the `referenceLine` `chartCon
 
 <Canvas of={ComponentStories.WithHighlightedMeasure} />
 
+<StackAggregateTotalsStory
+  of={ComponentStories.WithStackAggregateTotalsAndTooltip}
+  description={<>You can display a total label at the end of each stacked bar group by setting <code>chartConfig.showStackAggregateTotals</code> to <code>true</code>. The tooltip includes the total automatically when only a single bar per dimension is present.</>}
+/>
+
+<CustomTooltipTotalStory
+  of={ComponentStories.WithCustomTooltipTotal}
+  description={<>When multiple bars per dimension are present (e.g. stacked + standalone), the built-in tooltip total is not available. You can provide a custom tooltip via the <code>tooltipConfig.content</code> prop to display a total for specific measures.</>}
+/>
+
 <TooltipStory of={ComponentStories.WithCustomTooltipConfig} />
 
 <LegendStory of={ComponentStories.WithCustomLegendConfig} />

packages/charts/src/components/BarChart/BarChart.stories.tsx

@@ -1,6 +1,7 @@
 import type { Meta, StoryObj } from '@storybook/react-vite';
 import {
   complexDataSet,
+  CustomTooltipContent,
   legendConfig,
   secondaryDimensionDataSet,
   simpleDataSet,
@@ -165,6 +166,56 @@ export const WithNormalizedStacks: Story = {
   args: stackedNormalizedConfig,
 };
 
+export const WithStackAggregateTotalsAndTooltip: Story = {
+  name: 'With Stack Aggregate Totals',
+  args: {
+    dataset: complexDataSet.slice(0, 3),
+    measures: [
+      {
+        accessor: 'users',
+        stackId: 'A',
+        label: 'Users',
+      },
+      {
+        accessor: 'sessions',
+        stackId: 'A',
+        label: 'Active Sessions',
+      },
+    ],
+    chartConfig: {
+      showStackAggregateTotals: true,
+    },
+  },
+};
+
+export const WithCustomTooltipTotal: Story = {
+  args: {
+    dataset: complexDataSet.slice(0, 5),
+    measures: [
+      {
+        accessor: 'users',
+        stackId: 'A',
+        label: 'Users',
+      },
+      {
+        accessor: 'sessions',
+        stackId: 'A',
+        label: 'Active Sessions',
+      },
+      {
+        accessor: 'volume',
+        label: 'Vol.',
+      },
+    ],
+    chartConfig: {
+      showStackAggregateTotals: true,
+    },
+    tooltipConfig: {
+      content: <CustomTooltipContent />,
+    },
+  },
+};
+
 export const WithCustomTooltipConfig: Story = {
   args: tooltipConfig,
 };

packages/charts/src/components/BarChart/index.tsx

@@ -33,6 +33,8 @@ import type { IChartMeasure } from '../../interfaces/IChartMeasure.js';
 import { ChartContainer } from '../../internal/ChartContainer.js';
 import { ChartDataLabel } from '../../internal/ChartDataLabel.js';
 import { defaultFormatter } from '../../internal/defaults.js';
+import { StackAggregateLabel } from '../../internal/StackAggregateLabel.js';
+import { StackedTooltipContent } from '../../internal/StackedTooltipContent.js';
 import { brushProps, tickLineConfig, tooltipContentStyle, tooltipFillOpacity } from '../../internal/staticProps.js';
 import { getCellColors, resolvePrimaryAndSecondaryMeasures } from '../../internal/Utils.js';
 import { XAxisTicks } from '../../internal/XAxisTicks.js';
@@ -168,11 +170,12 @@ const BarChart = forwardRef<HTMLDivElement, BarChartProps>((props, ref) => {
   };
   const referenceLine = chartConfig.referenceLine;
 
-  const { dimensions, measures } = usePrepareDimensionsAndMeasures(
+  const { dimensions, measures, stackGroups, lastInStack } = usePrepareDimensionsAndMeasures(
     props.dimensions,
     props.measures,
     dimensionDefaults,
     measureDefaults,
+    chartConfig.showStackAggregateTotals,
   );
 
   const tooltipValueFormatter = useTooltipFormatter(measures);
@@ -224,6 +227,10 @@ const BarChart = forwardRef<HTMLDivElement, BarChartProps>((props, ref) => {
 
   const { isMounted, handleBarAnimationStart, handleBarAnimationEnd } = useCancelAnimationFallback(noAnimation);
 
+  const stackGroupKeys = Object.keys(stackGroups);
+  const showStackTotalInTooltip =
+    chartConfig.showStackAggregateTotals && stackGroupKeys.length === 1 && measures.every((m) => m.stackId != null);
+
   const { chartConfig: _0, dimensions: _1, measures: _2, ...propsWithoutOmitted } = rest;
   return (
     <ChartContainer
@@ -337,6 +344,17 @@ const BarChart = forwardRef<HTMLDivElement, BarChartProps>((props, ref) => {
                   valueAccessor={valueAccessor(element.accessor)}
                   content={<ChartDataLabel config={element} chartType="bar" position={'insideRight'} />}
                 />
+                {chartConfig.showStackAggregateTotals &&
+                  element.stackId &&
+                  typeof element.accessor === 'string' &&
+                  lastInStack.has(element.accessor) && (
+                    <LabelList
+                      data={dataset}
+                      valueAccessor={valueAccessor(element.accessor)}
+                      position="right"
+                      content={<StackAggregateLabel stackAccessors={stackGroups[element.stackId]} dataset={dataset} />}
+                    />
+                  )}
                 {dataset.map((data, i) => {
                   return (
                     <Cell
@@ -374,6 +392,14 @@ const BarChart = forwardRef<HTMLDivElement, BarChartProps>((props, ref) => {
             contentStyle={tooltipContentStyle}
             labelFormatter={tooltipLabelFormatter}
             {...tooltipConfig}
+            {...(showStackTotalInTooltip && {
+              content: (
+                <StackedTooltipContent
+                  stackAccessors={stackGroups[stackGroupKeys[0]]}
+                  totalFormatter={chartConfig.stackAggregateTotalFormatter}
+                />
+              ),
+            })}
           />
         )}
         {!!chartConfig.zoomingTool && (

packages/charts/src/components/ColumnChart/ColumnChart.cy.tsx

@@ -1,6 +1,11 @@
 import { complexDataSet } from '../../resources/DemoProps.js';
 import { ColumnChart } from './index.js';
-import { cypressPassThroughTestsFactory, testChartLegendConfig, testChartZoomingTool } from '@/cypress/support/utils';
+import {
+  cypressPassThroughTestsFactory,
+  testChartLegendConfig,
+  testChartZoomingTool,
+  testStackAggregateTotals,
+} from '@/cypress/support/utils';
 
 const dimensions = [
   {
@@ -83,4 +88,13 @@ describe('ColumnChart', () => {
   testChartLegendConfig(ColumnChart, { dataset: complexDataSet, dimensions, measures });
 
   cypressPassThroughTestsFactory(ColumnChart, { dimensions: [], measures: [] });
+
+  testStackAggregateTotals(ColumnChart, {
+    dataset: complexDataSet.slice(0, 3),
+    dimensions,
+    measures: [
+      { accessor: 'users', stackId: 'A', label: 'Users' },
+      { accessor: 'sessions', stackId: 'A', label: 'Active Sessions' },
+    ],
+  });
 });

packages/charts/src/components/ColumnChart/ColumnChart.mdx

@@ -3,6 +3,8 @@ import { Canvas, Meta } from '@storybook/addon-docs/blocks';
 import TooltipStory from '../../resources/TooltipConfig.mdx';
 import LegendStory from '../../resources/LegendConfig.mdx';
 import NormalizedStackedChartStory from '../../resources/NormalizedStackedChart.mdx';
+import StackAggregateTotalsStory from '../../resources/StackAggregateTotals.mdx';
+import CustomTooltipTotalStory from '../../resources/CustomTooltipTotal.mdx';
 import * as ComponentStories from './ColumnChart.stories';
 
 <Meta of={ComponentStories} />
@@ -62,10 +64,20 @@ You can set a reference line to any value by using the `referenceLine` `chartCon
 
 <Canvas of={ComponentStories.WithReferenceLine} />
 
-## With Highlighted Measures
+### With Highlighted Measures
 
 <Canvas of={ComponentStories.WithHighlightedMeasure} />
 
+<StackAggregateTotalsStory
+  of={ComponentStories.WithStackAggregateTotals}
+  description={<>You can display a total label at the top of each stacked column group by setting <code>chartConfig.showStackAggregateTotals</code> to <code>true</code>. The tooltip includes the total automatically when only a single column per dimension is present.</>}
+/>
+
+<CustomTooltipTotalStory
+  of={ComponentStories.WithCustomTooltipTotal}
+  description={<>When multiple columns per dimension are present (e.g. stacked + standalone), the built-in tooltip total is not available. You can provide a custom tooltip via the <code>tooltipConfig.content</code> prop to display a total for specific measures.</>}
+/>
+
 <TooltipStory of={ComponentStories.WithCustomTooltipConfig} />;
 
 <LegendStory of={ComponentStories.WithCustomLegendConfig} />

packages/charts/src/components/ColumnChart/ColumnChart.stories.tsx

@@ -1,6 +1,7 @@
 import type { Meta, StoryObj } from '@storybook/react-vite';
 import {
   complexDataSet,
+  CustomTooltipContent,
   legendConfig,
   secondaryDimensionDataSet,
   simpleDataSet,
@@ -156,6 +157,57 @@ export const WithHighlightedMeasure: Story = {
   },
 };
 
+export const WithStackAggregateTotals: Story = {
+  args: {
+    dataset: complexDataSet.slice(0, 3),
+    dimensions: [{ accessor: 'name' }],
+    measures: [
+      {
+        accessor: 'users',
+        stackId: 'A',
+        label: 'Users',
+      },
+      {
+        accessor: 'sessions',
+        stackId: 'A',
+        label: 'Active Sessions',
+      },
+    ],
+    chartConfig: {
+      showStackAggregateTotals: true,
+    },
+  },
+};
+
+export const WithCustomTooltipTotal: Story = {
+  args: {
+    dataset: complexDataSet.slice(0, 5),
+    dimensions: [{ accessor: 'name' }],
+    measures: [
+      {
+        accessor: 'users',
+        stackId: 'A',
+        label: 'Users',
+      },
+      {
+        accessor: 'sessions',
+        stackId: 'A',
+        label: 'Active Sessions',
+      },
+      {
+        accessor: 'volume',
+        label: 'Vol.',
+      },
+    ],
+    chartConfig: {
+      showStackAggregateTotals: true,
+    },
+    tooltipConfig: {
+      content: <CustomTooltipContent />,
+    },
+  },
+};
+
 export const WithCustomTooltipConfig: Story = {
   args: tooltipConfig,
 };