Make chart data point links clickable

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## unreleased
 
+- **Beta:** Chart data points can now include a `link`. The link is shown in an interactive tooltip, and clicking the data point itself also follows it. Interactive tooltips depend on [ApexCharts PR #5307](https://github.com/apexcharts/apexcharts.js/pull/5307).
+
 ## v0.46.2
 
 - Numeric x values on Cartesian charts now explicitly use a continuous numeric axis, preventing fractional tick positions from being displayed as misleading rounded integers.

examples/official-site/sqlpage/migrations/01_documentation.sql

@@ -688,6 +688,7 @@ INSERT INTO parameter(component, name, description, type, top_level, optional) S
     ('label', 'An alias for parameter "x". On a row that draws a reference line, the text to display next to the line.', 'TEXT', FALSE, TRUE),
     ('value', 'An alias for parameter "y"', 'REAL', FALSE, TRUE),
     ('series', 'If multiple series are represented and share the same y-axis, this parameter can be used to distinguish between them.', 'TEXT', FALSE, TRUE),
+    ('link', 'Beta: makes this data point clickable and adds the same link to its tooltip. Interactive tooltips depend on ApexCharts issue #4469.', 'URL', FALSE, TRUE),
     ('yline', 'Draws a reference line across the chart at this value of the y axis instead of plotting a point, to show a limit such as a quota or an alarm threshold. Not drawn if it falls outside of the axis, so set ymax when the limit is above the data.', 'REAL', FALSE, TRUE),
     ('yline_end', 'Makes the yline a band instead of a line, reaching to this value.', 'REAL', FALSE, TRUE),
     ('xline', 'Draws a reference line across the chart at this position of the x axis instead of plotting a point, to mark an event such as a deployment. A date or a timestamp when time is set, otherwise one of the x values.', 'TEXT', FALSE, TRUE),
@@ -789,10 +790,10 @@ The `color` property sets the color of each series separately, in order.
         { "series": "PostgreSQL", "x": "2010", "y": 65},{ "series": "SQLite", "x": "2010", "y": 62},{ "series": "MySQL", "x": "2010", "y": 83},
         { "series": "PostgreSQL", "x": "2020", "y": 73},{ "series": "SQLite", "x": "2020", "y": 38},{ "series": "MySQL", "x": "2020", "y": 87}
       ]')),
-    ('chart', 'A timeline displaying events with a start and an end date',
+    ('chart', 'A timeline displaying events with a start and an end date. A data row can include a beta `link` to make both the bar and its tooltip clickable; see [ApexCharts issue #4469](https://github.com/apexcharts/apexcharts.js/issues/4469).',
     json('[
         {"component":"chart", "title": "Project Timeline", "type": "rangeBar", "time": true, "color": ["teal", "cyan"], "labels": true, "xmin": "2021-12-28", "xmax": "2022-01-04" },
-        {"series": "Phase 1", "label": "Operations", "value": ["2021-12-29", "2022-01-02"]},
+        {"series": "Phase 1", "label": "Operations", "value": ["2021-12-29", "2022-01-02"], "link": "/examples/chart.sql?phase=1"},
         {"series": "Phase 2", "label": "Operations", "value": ["2022-01-03", "2022-01-04"]},
         {"series": "Yearly maintenance", "label": "Maintenance", "value": ["2022-01-01", "2022-01-03"]}
     ]')),

sqlpage/apexcharts.js

@@ -51,7 +51,7 @@ sqlpage_chart = (() => {
   };
 
   /** @typedef {number|string|Date} XValue */
-  /** @typedef { {x:XValue, y:number|null, z?:number, fillColor?:string} } ChartPoint */
+  /** @typedef { {x:XValue, y:number|null, z?:number, fillColor?:string, link?:string} } ChartPoint */
   /** @typedef { {name:string, data:ChartPoint[]} } ChartSeries */
   /** @typedef { { [name:string]: ChartSeries } } Series */
 
@@ -200,7 +200,7 @@ sqlpage_chart = (() => {
     const reference_rows = data.points.filter((row) => !Array.isArray(row));
     /** @type { Series } */
     const series_map = {};
-    for (const [name, old_x, old_y, color, z] of points) {
+    for (const [name, old_x, old_y, color, z, link] of points) {
       series_map[name] = series_map[name] || { name, data: [] };
       let x = old_x;
       let y = old_y;
@@ -210,7 +210,13 @@ sqlpage_chart = (() => {
           y = y.map((y) => new Date(y).getTime());
         else x = new Date(x);
       }
-      series_map[name].data.push({ x, y, z, fillColor: named_color(color) });
+      series_map[name].data.push({
+        x,
+        y,
+        z,
+        link,
+        fillColor: named_color(color),
+      });
     }
     if (data.xmin == null) data.xmin = undefined;
     if (data.xmax == null) data.xmax = undefined;
@@ -252,6 +258,7 @@ sqlpage_chart = (() => {
       chart_type === "rangeBar" || (chart_type === "bar" && !!data.horizontal);
     const value_axis = inverted ? "x" : "y";
     const category_axis = inverted ? "y" : "x";
+    const has_point_links = points.some((point) => point[5]);
     const options = {
       annotations: {
         [`${value_axis}axis`]: reference_lines(
@@ -283,6 +290,12 @@ sqlpage_chart = (() => {
         zoom: {
           enabled: false,
         },
+        events: {
+          dataPointSelection: (_event, _chart, args) => {
+            const link = pointLink(args, points);
+            if (link) window.location.assign(link);
+          },
+        },
       },
       theme: {
         mode: isDarkTheme ? "dark" : "light",
@@ -355,8 +368,10 @@ sqlpage_chart = (() => {
       },
       tooltip: {
         fillSeriesColor: false,
-        custom:
-          chart_type === "bubble" || chart_type === "scatter"
+        interactive: has_point_links,
+        custom: has_point_links
+          ? (args) => chartTooltip(args, points)
+          : chart_type === "bubble" || chart_type === "scatter"
             ? bubbleTooltip
             : undefined,
         y: {
@@ -396,17 +411,25 @@ sqlpage_chart = (() => {
     c.removeAttribute("data-pre-init");
   }
 
-  function bubbleTooltip({ seriesIndex, dataPointIndex, w }) {
-    const { name, data } = w.config.series[seriesIndex];
-    const point = data[dataPointIndex];
+  function chartTooltip({ seriesIndex, dataPointIndex, w }, raw_points) {
+    const series = w.config.series[seriesIndex];
+    const has_series_data = Array.isArray(series?.data);
+    const point_index = has_series_data ? dataPointIndex : seriesIndex;
+    const raw_point = raw_points[point_index];
+    const name = series?.name || w.config.labels?.[point_index] || "";
+    const point = has_series_data
+      ? series.data[dataPointIndex]
+      : { y: raw_point?.[2], z: raw_point?.[4] };
+    const link = pointLink({ seriesIndex, dataPointIndex, w }, raw_points);
 
     const tooltip = document.createElement("div");
     tooltip.className = "apexcharts-tooltip-text";
     tooltip.style.fontFamily = "inherit";
 
-    const seriesName = document.createElement("div");
+    const seriesName = document.createElement(link ? "a" : "div");
     seriesName.className = "apexcharts-tooltip-y-group";
     seriesName.style.fontWeight = "bold";
+    if (seriesName instanceof HTMLAnchorElement) seriesName.href = link;
     seriesName.innerText = name;
     tooltip.appendChild(seriesName);
 
@@ -424,13 +447,29 @@ sqlpage_chart = (() => {
       axisValue.appendChild(labelSpan);
       const valueSpan = document.createElement("span");
       valueSpan.className = "apexcharts-tooltip-text-y-value";
-      valueSpan.innerText = value;
+      const formatter = axis === "y" && w.config.tooltip.y.formatter;
+      const format = (v) =>
+        formatter ? formatter(v, { seriesIndex, dataPointIndex, w }) : v;
+      valueSpan.innerText = Array.isArray(value)
+        ? value.map(format).join(" - ")
+        : format(value);
       axisValue.appendChild(valueSpan);
       tooltip.appendChild(axisValue);
     }
     return tooltip.outerHTML;
   }
 
+  function pointLink({ seriesIndex, dataPointIndex, w }, raw_points) {
+    const series = w.config.series[seriesIndex];
+    return Array.isArray(series?.data)
+      ? series.data[dataPointIndex]?.link
+      : raw_points[seriesIndex]?.[5];
+  }
+
+  function bubbleTooltip(args) {
+    return chartTooltip(args, []);
+  }
+
   return sqlpage_chart;
 })();
 

sqlpage/sqlpage.css

@@ -64,6 +64,16 @@ code {
   color: inherit;
 }
 
+.apexcharts-tooltip a {
+  color: currentColor;
+  text-decoration: underline;
+}
+
+.apexcharts-canvas:has(.apexcharts-tooltip.apexcharts-active a)
+  .apexcharts-svg {
+  cursor: pointer;
+}
+
 /** table **/
 .table-freeze-headers thead {
   position: sticky;

sqlpage/templates/chart.handlebars

@@ -51,8 +51,9 @@
             {{~ stringify (default series (default ../title "")) ~}},
             {{~ stringify (default x label) ~}},
             {{~ stringify (default y value) ~}}
-            {{~#if (or color z)}}, {{~ stringify color ~}} {{~/if~}}
-            {{~#if z}}, {{~ stringify z ~}} {{~/if~}}
+            {{~#if (or color z link)}}, {{~ stringify color ~}} {{~/if~}}
+            {{~#if (or z link)}}, {{~ stringify z ~}} {{~/if~}}
+            {{~#if link}}, {{~ stringify link ~}} {{~/if~}}
         ]
         {{~/if~}}
     {{~/each_row~}}

tests/end-to-end/fixtures/chart/link-bar.sql

@@ -0,0 +1,4 @@
+SELECT 'chart' AS component, 'test-chart' AS id, 'Chart test fixture' AS title,
+    'bar' AS type;
+SELECT 'Points' AS series, 'Linked' AS label, 10 AS value, '/linked.sql' AS link;
+SELECT 'Points' AS series, 'Linked too' AS label, 20 AS value, '/linked-too.sql' AS link;

tests/end-to-end/fixtures/chart/link-line.sql

@@ -0,0 +1,4 @@
+SELECT 'chart' AS component, 'test-chart' AS id, 'Chart test fixture' AS title,
+    'line' AS type, 8 AS marker;
+SELECT 'Points' AS series, 1 AS x, 10 AS y, '/linked.sql' AS link;
+SELECT 'Points' AS series, 2 AS x, 20 AS y, '/linked-too.sql' AS link;

tests/end-to-end/fixtures/chart/link-pie.sql

@@ -0,0 +1,4 @@
+SELECT 'chart' AS component, 'test-chart' AS id, 'Chart test fixture' AS title,
+    'pie' AS type;
+SELECT 'Points' AS series, 'A' AS label, 10 AS value, '/linked.sql' AS link;
+SELECT 'Points' AS series, 'B' AS label, 20 AS value, '/linked-too.sql' AS link;

tests/end-to-end/fixtures/chart/link-scatter.sql

@@ -0,0 +1,4 @@
+SELECT 'chart' AS component, 'test-chart' AS id, 'Chart test fixture' AS title,
+    'scatter' AS type, 8 AS marker;
+SELECT 'Points' AS series, 1 AS x, 1 AS y, '/linked.sql' AS link;
+SELECT 'Points' AS series, 2 AS x, 2 AS y, '/linked-too.sql' AS link;

tests/end-to-end/fixtures/chart/link.sql

@@ -0,0 +1,7 @@
+SELECT 'chart' AS component, 'test-chart' AS id, 'Chart test fixture' AS title,
+    'rangeBar' AS type, TRUE AS time;
+SELECT 'Design' AS series, 'Alice' AS label,
+    '2024-03-01' AS value, '2024-03-05' AS value,
+    '/workpackage_edit.sql?workpackage_name=Design' AS link;
+SELECT 'Research' AS series, 'Bob' AS label,
+    '2024-03-06' AS value, '2024-03-10' AS value;

tests/end-to-end/fixtures/chart/test.ts

@@ -367,6 +367,76 @@ test("leaves a rangeBar chart on a category axis alone", async ({ page }) => {
   expect(chart.shapes).toHaveLength(2);
 });
 
+test("shows a data point link in a rangeBar tooltip", async ({ page }) => {
+  await renderChart(page, "link");
+
+  await page.locator("#test-chart .apexcharts-rangebar-area").first().hover();
+  const link = page.locator(
+    "#test-chart .apexcharts-tooltip .apexcharts-tooltip-text > a",
+  );
+  await expect(link).toHaveText("Design");
+  await expect(link).toHaveAttribute(
+    "href",
+    "/workpackage_edit.sql?workpackage_name=Design",
+  );
+  await expect(
+    page.locator("#test-chart .apexcharts-rangebar-area").first(),
+  ).toHaveCSS("cursor", "pointer");
+  await page.locator("#test-chart .apexcharts-rangebar-area").nth(1).hover();
+  await expect(
+    page.locator("#test-chart .apexcharts-rangebar-area").nth(1),
+  ).not.toHaveCSS("cursor", "pointer");
+  await page.locator("#test-chart .apexcharts-rangebar-area").first().hover();
+  const colors = await link.evaluate((anchor) => {
+    const tooltip = anchor.closest(".apexcharts-tooltip");
+    if (!tooltip) throw new Error("Link has no tooltip");
+    return {
+      link: getComputedStyle(anchor).color,
+      tooltip: getComputedStyle(tooltip).color,
+    };
+  });
+  expect(colors.link).toBe(colors.tooltip);
+  await page.locator("#test-chart .apexcharts-rangebar-area").first().click();
+  await expect(page).toHaveURL(/workpackage_edit/);
+});
+
+for (const [type, mark] of [
+  ["bar", ".apexcharts-bar-area"],
+  ["line", ".apexcharts-marker"],
+  ["scatter", ".apexcharts-marker"],
+]) {
+  test(`shows a data point link in a ${type} tooltip`, async ({ page }) => {
+    await renderChart(page, `link-${type}`);
+
+    const marks = page.locator(`#test-chart ${mark}`);
+    await marks.nth(0).hover({ force: true });
+    await expect(page.locator("#test-chart .apexcharts-tooltip a")).toHaveCount(
+      1,
+    );
+  });
+}
+
+test("links each slice of a pie chart from its own row", async ({ page }) => {
+  const chart = await renderChart(page, "link-pie");
+
+  expect(chart.failures).toEqual([]);
+  const slices = page.locator("#test-chart .apexcharts-pie-area");
+  const link = page.locator("#test-chart .apexcharts-tooltip a");
+  await slices.nth(0).hover();
+  await expect(link).toHaveAttribute("href", "/linked.sql");
+  await slices.nth(1).hover();
+  await expect(link).toHaveAttribute("href", "/linked-too.sql");
+});
+
+test("formats date ranges in a linked tooltip", async ({ page }) => {
+  await renderChart(page, "link");
+
+  await page.locator("#test-chart .apexcharts-rangebar-area").first().hover();
+  await expect(
+    page.locator("#test-chart .apexcharts-tooltip"),
+  ).not.toContainText("1709251200000");
+});
+
 test("leaves a treemap chart alone", async ({ page }) => {
   const chart = await renderChart(page, "treemap");