Fixed tooltips in bar charts

src/visits/helpers/DefaultChart.tsx

@@ -19,7 +19,6 @@ import {
 import { PieChartLegend } from './PieChartLegend';
 
 export interface DefaultChartProps {
-  title: Function | string;
   stats: Stats;
   isBarChart?: boolean;
   max?: number;
@@ -28,19 +27,14 @@ export interface DefaultChartProps {
   onClick?: (label: string) => void;
 }
 
-const generateGraphData = (
-  title: Function | string,
+const generateChartDatasets = (
   isBarChart: boolean,
-  labels: string[],
   data: number[],
-  highlightedData?: number[],
+  highlightedData: number[],
   highlightedLabel?: string,
-): ChartData => ({
-  labels,
-  datasets: [
-    {
-      title,
-      label: highlightedData ? 'Non-selected' : 'Visits',
+): ChartDataset[] => {
+  const mainDataset: ChartDataset = {
+    label: highlightedLabel ? 'Non-selected' : 'Visits',
     data,
     backgroundColor: isBarChart ? MAIN_COLOR_ALPHA : [
       '#97BBCD',
@@ -57,16 +51,32 @@ const generateGraphData = (
     ],
     borderColor: isBarChart ? MAIN_COLOR : isDarkThemeEnabled() ? PRIMARY_DARK_COLOR : PRIMARY_LIGHT_COLOR,
     borderWidth: 2,
-    },
-    highlightedData && {
-      title,
+  };
+
+  if (!isBarChart) {
+    return [ mainDataset ];
+  }
+
+  const highlightedDataset: ChartDataset = {
     label: highlightedLabel ?? 'Selected',
     data: highlightedData,
     backgroundColor: HIGHLIGHTED_COLOR_ALPHA,
     borderColor: HIGHLIGHTED_COLOR,
     borderWidth: 2,
-    },
-  ].filter(Boolean) as ChartDataset[],
+  };
+
+  return [ mainDataset, highlightedDataset ];
+};
+
+const generateChartData = (
+  isBarChart: boolean,
+  labels: string[],
+  data: number[],
+  highlightedData: number[],
+  highlightedLabel?: string,
+): ChartData => ({
+  labels,
+  datasets: generateChartDatasets(isBarChart, data, highlightedData, highlightedLabel),
 });
 
 const dropLabelIfHidden = (label: string) => label.startsWith('hidden') ? '' : label;
@@ -93,7 +103,7 @@ const chartElementAtEvent = (
 const statsAreDefined = (stats: Stats | undefined): stats is Stats => !!stats && Object.keys(stats).length > 0;
 
 const DefaultChart = (
-  { title, isBarChart = false, stats, max, highlightedStats, highlightedLabel, onClick }: DefaultChartProps,
+  { isBarChart = false, stats, max, highlightedStats, highlightedLabel, onClick }: DefaultChartProps,
 ) => {
   const Component = isBarChart ? Bar : Doughnut;
   const [ chartRef, setChartRef ] = useState<Chart | undefined>(); // Cannot use useRef here
@@ -107,13 +117,14 @@ const DefaultChart = (
       return acc;
     }, { ...stats }),
   );
-  const highlightedData = statsAreDefined(highlightedStats) ? fillTheGaps(highlightedStats, labels) : undefined;
+  const highlightedData = fillTheGaps(highlightedStats ?? {}, labels);
 
   const options: ChartOptions = {
     plugins: {
       legend: { display: false },
       tooltip: {
         intersect: !isBarChart,
+        mode: isBarChart ? 'y' : 'index',
         // Do not show tooltip on items with empty label when in a bar chart
         filter: ({ label }) => !isBarChart || label !== '',
         callbacks: {
@@ -136,10 +147,10 @@ const DefaultChart = (
     onHover: isBarChart ? pointerOnHover : undefined,
     indexAxis: isBarChart ? 'y' : 'x',
   };
-  const graphData = generateGraphData(title, isBarChart, labels, data, highlightedData, highlightedLabel);
+  const chartData = generateChartData(isBarChart, labels, data, highlightedData, highlightedLabel);
   const height = determineHeight(isBarChart, labels);
 
-  // Provide a key based on the height, so that every time the dataset changes, a new graph is rendered
+  // Provide a key based on the height, so that every time the dataset changes, a new chart is rendered
   return (
     <div className="row">
       <div className={classNames('col-sm-12', { 'col-md-7': !isBarChart })}>
@@ -148,7 +159,7 @@ const DefaultChart = (
             setChartRef(element ?? undefined);
           }}
           key={height}
-          data={graphData}
+          data={chartData}
           options={options}
           height={height}
           getElementAtEvent={chartElementAtEvent(labels, onClick) as any}

src/visits/helpers/GraphCard.tsx

@@ -4,6 +4,7 @@ import DefaultChart, { DefaultChartProps } from './DefaultChart';
 import './GraphCard.scss';
 
 interface GraphCardProps extends DefaultChartProps {
+  title: Function | string;
   footer?: ReactNode;
 }
 
@@ -11,7 +12,7 @@ const GraphCard = ({ title, footer, ...rest }: GraphCardProps) => (
   <Card>
     <CardHeader className="graph-card__header">{typeof title === 'function' ? title() : title}</CardHeader>
     <CardBody>
-      <DefaultChart title={title} {...rest} />
+      <DefaultChart {...rest} />
     </CardBody>
     {footer && <CardFooter className="graph-card__footer--sticky">{footer}</CardFooter>}
   </Card>

src/visits/helpers/LineChartCard.tsx

@@ -1,4 +1,4 @@
-import { useState, useMemo } from 'react';
+import { useState, useMemo, FC } from 'react';
 import {
   Card,
   CardHeader,
@@ -183,14 +183,19 @@ const LineChartCard = (
     () => fillTheGaps(groupVisitsByStep(step, reverse(highlightedVisits)), labels),
     [ highlightedVisits, step, labels ],
   );
+  const generateChartDatasets = (): ChartDataset[] => {
+    const mainDataset = generateDataset(groupedVisits, 'Visits', MAIN_COLOR);
 
-  const data: ChartData = {
-    labels,
-    datasets: [
-      generateDataset(groupedVisits, 'Visits', MAIN_COLOR),
-      highlightedVisits.length > 0 && generateDataset(groupedHighlighted, highlightedLabel, HIGHLIGHTED_COLOR),
-    ].filter(Boolean) as ChartDataset[],
+    if (highlightedVisits.length === 0) {
+      return [ mainDataset ];
+    }
+
+    const highlightedDataset = generateDataset(groupedHighlighted, highlightedLabel, HIGHLIGHTED_COLOR);
+
+    return [ mainDataset, highlightedDataset ];
   };
+  const generateChartData = (): ChartData => ({ labels, datasets: generateChartDatasets() });
+
   const options: ChartOptions = {
     maintainAspectRatio: false,
     plugins: {
@@ -213,8 +218,15 @@ const LineChartCard = (
         title: { display: true, text: STEPS_MAP[step] },
       },
     },
-    onHover: (pointerOnHover) as any, // TODO Types seem to be incorrectly defined in @types/chart.js
+    onHover: pointerOnHover,
   };
+  const LineChart: FC = () => (
+    <Line
+      data={generateChartData()}
+      options={options}
+      getElementAtEvent={chartElementAtEvent(labels, datasetsByPoint, setSelectedVisits) as any}
+    />
+  );
 
   return (
     <Card>
@@ -241,11 +253,10 @@ const LineChartCard = (
         </div>
       </CardHeader>
       <CardBody className="line-chart-card__body">
-        <Line
-          data={data}
-          options={options}
-          getElementAtEvent={chartElementAtEvent(labels, datasetsByPoint, setSelectedVisits) as any}
-        />
+        {/* It's VERY IMPORTANT to render two different components here, as one has 1 dataset and the other has 2 */}
+        {/* Using the same component causes a crash when switching from 1 to 2 datasets, and then back to 1 dataset */}
+        {highlightedVisits.length > 0 && <LineChart />}
+        {highlightedVisits.length === 0 && <LineChart />}
       </CardBody>
     </Card>
   );

src/visits/helpers/SortableBarGraph.tsx

@@ -14,6 +14,7 @@ const pickKeyFromPair = ([ key ]: StatsRow) => key;
 const pickValueFromPair = ([ , value ]: StatsRow) => value;
 
 interface SortableBarGraphProps extends DefaultChartProps {
+  title: Function | string;
   sortingItems: Record<string, string>;
   withPagination?: boolean;
   extraHeaderContent?: Function;