apertureless · dangreen · Dec 5, 2022 · Dec 5, 2022
diff --git a/.size-limit.json b/.size-limit.json
@@ -1,7 +1,7 @@
 [
   {
     "path": "dist/index.js",
-    "limit": "1.7 KB",
+    "limit": "1.9 KB",
     "webpack": false,
     "running": false
   },

diff --git a/sandboxes/events/index.html b/sandboxes/events/index.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <script type="module" defer src="./index.ts"></script>
+  </head>
+  <body>
+    <div id="app"></div>
+  </body>
+</html>
diff --git a/sandboxes/events/index.ts b/sandboxes/events/index.ts
@@ -0,0 +1,4 @@
+import { createApp } from 'vue'
+import App from './src/App.vue'
+
+createApp(App).mount('#app')
diff --git a/sandboxes/events/package.json b/sandboxes/events/package.json
@@ -0,0 +1,16 @@
+{
+  "type": "module",
+  "scripts": {
+    "start": "vite"
+  },
+  "dependencies": {
+    "chart.js": "^4.0.0",
+    "vue": "^3.2.31",
+    "vue-chartjs": "^5.0.0"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-vue": "^3.0.1",
+    "typescript": "^4.9.3",
+    "vite": "^3.2.4"
+  }
+}
diff --git a/sandboxes/events/src/App.vue b/sandboxes/events/src/App.vue
@@ -0,0 +1,89 @@
+<template>
+  <Chart
+    ref="chartRef"
+    type="bar"
+    :data="data"
+    :options="options"
+    @click="onClick"
+  />
+</template>
+
+<script lang="ts">
+import { ref } from 'vue'
+import {
+  Chart as ChartJS,
+  Title,
+  Tooltip,
+  Legend,
+  BarElement,
+  CategoryScale,
+  LinearScale,
+  InteractionItem
+} from 'chart.js'
+import {
+  ChartComponentRef,
+  Chart,
+  getDatasetAtEvent,
+  getElementAtEvent,
+  getElementsAtEvent
+} from 'vue-chartjs'
+import * as chartConfig from './chartConfig.js'
+
+ChartJS.register(CategoryScale, LinearScale, BarElement, Title, Tooltip, Legend)
+
+export default {
+  name: 'App',
+  components: {
+    Chart
+  },
+  setup() {
+    const datasetAtEvent = (dataset: InteractionItem[]) => {
+      if (!dataset.length) return
+
+      const datasetIndex = dataset[0].datasetIndex
+
+      console.log('dataset', chartConfig.data.datasets[datasetIndex].label)
+    }
+
+    const elementAtEvent = (element: InteractionItem[]) => {
+      if (!element.length) return
+
+      const { datasetIndex, index } = element[0]
+
+      console.log(
+        'element',
+        chartConfig.data.labels[index],
+        chartConfig.data.datasets[datasetIndex].data[index]
+      )
+    }
+
+    const elementsAtEvent = (elements: InteractionItem[]) => {
+      if (!elements.length) return
+
+      console.log('elements', elements)
+    }
+
+    const chartRef = ref<ChartComponentRef>(null)
+
+    const onClick = (event: MouseEvent) => {
+      const {
+        value: { chart }
+      } = chartRef
+
+      if (!chart) {
+        return
+      }
+
+      datasetAtEvent(getDatasetAtEvent(chart, event))
+      elementAtEvent(getElementAtEvent(chart, event))
+      elementsAtEvent(getElementsAtEvent(chart, event))
+    }
+
+    return {
+      chartRef,
+      onClick,
+      ...chartConfig
+    }
+  }
+}
+</script>
diff --git a/sandboxes/events/src/chartConfig.ts b/sandboxes/events/src/chartConfig.ts
@@ -0,0 +1,28 @@
+export const data = {
+  labels: [
+    'January',
+    'February',
+    'March',
+    'April',
+    'May',
+    'June',
+    'July',
+    'August',
+    'September',
+    'October',
+    'November',
+    'December'
+  ],
+  datasets: [
+    {
+      label: 'Data One',
+      backgroundColor: '#f87979',
+      data: [40, 20, 12, 39, 10, 40, 39, 80, 40, 20, 12, 11]
+    }
+  ]
+}
+
+export const options = {
+  responsive: true,
+  maintainAspectRatio: false
+}
diff --git a/sandboxes/events/vite.config.js b/sandboxes/events/vite.config.js
@@ -0,0 +1,6 @@
+import { defineConfig } from 'vite'
+import vue from '@vitejs/plugin-vue'
+
+export default defineConfig({
+  plugins: [vue()]
+})
diff --git a/src/index.ts b/src/index.ts
@@ -12,6 +12,11 @@ import {
 } from './typedCharts.js'
 
 export type { ChartProps, ChartComponentRef } from './types.js'
+export {
+  getDatasetAtEvent,
+  getElementAtEvent,
+  getElementsAtEvent
+} from './utils.js'
 export {
   Chart,
   createTypedChart,

diff --git a/src/utils.ts b/src/utils.ts
@@ -91,3 +91,48 @@ export function cloneData<
 
   return nextData
 }
+
+/**
+ * Get dataset from mouse click event
+ * @param chart - Chart.js instance
+ * @param event - Mouse click event
+ * @returns Dataset
+ */
+export function getDatasetAtEvent(chart: Chart, event: MouseEvent) {
+  return chart.getElementsAtEventForMode(
+    event,
+    'dataset',
+    { intersect: true },
+    false
+  )
+}
+
+/**
+ * Get single dataset element from mouse click event
+ * @param chart - Chart.js instance
+ * @param event - Mouse click event
+ * @returns Dataset
+ */
+export function getElementAtEvent(chart: Chart, event: MouseEvent) {
+  return chart.getElementsAtEventForMode(
+    event,
+    'nearest',
+    { intersect: true },
+    false
+  )
+}
+
+/**
+ * Get all dataset elements from mouse click event
+ * @param chart - Chart.js instance
+ * @param event - Mouse click event
+ * @returns Dataset
+ */
+export function getElementsAtEvent(chart: Chart, event: MouseEvent) {
+  return chart.getElementsAtEventForMode(
+    event,
+    'index',
+    { intersect: true },
+    false
+  )
+}
diff --git a/stories/chart.stories.ts b/stories/chart.stories.ts
@@ -0,0 +1,101 @@
+import 'chart.js/auto'
+import type { InteractionItem } from 'chart.js'
+import { ref } from 'vue'
+import {
+  ChartComponentRef,
+  Chart,
+  getDatasetAtEvent,
+  getElementAtEvent,
+  getElementsAtEvent
+} from '../src/index.js'
+import * as barChartConfig from '../sandboxes/bar/src/chartConfig.js'
+
+export default {
+  title: 'Chart',
+  component: Chart,
+  parameters: {
+    layout: 'centered'
+  }
+}
+
+export function Default(args) {
+  return {
+    components: { Chart },
+    template: '<Chart v-bind="args" />',
+    setup() {
+      return { args }
+    }
+  }
+}
+
+Default.args = {
+  id: 'bar-chart',
+  type: 'bar',
+  width: 400,
+  height: 400,
+  ...barChartConfig
+}
+
+export function Events(args) {
+  return {
+    components: { Chart },
+    template: '<Chart ref="chartRef" @click="onClick" v-bind="args" />',
+    setup() {
+      const datasetAtEvent = (dataset: InteractionItem[]) => {
+        if (!dataset.length) return
+
+        const datasetIndex = dataset[0].datasetIndex
+
+        console.log('dataset', barChartConfig.data.datasets[datasetIndex].label)
+      }
+
+      const elementAtEvent = (element: InteractionItem[]) => {
+        if (!element.length) return
+
+        const { datasetIndex, index } = element[0]
+
+        console.log(
+          'element',
+          barChartConfig.data.labels[index],
+          barChartConfig.data.datasets[datasetIndex].data[index]
+        )
+      }
+
+      const elementsAtEvent = (elements: InteractionItem[]) => {
+        if (!elements.length) return
+
+        console.log('elements', elements)
+      }
+
+      const chartRef = ref<ChartComponentRef>(null)
+
+      const onClick = (event: MouseEvent) => {
+        const {
+          value: { chart }
+        } = chartRef
+
+        if (!chart) {
+          return
+        }
+
+        datasetAtEvent(getDatasetAtEvent(chart, event))
+        elementAtEvent(getElementAtEvent(chart, event))
+        elementsAtEvent(getElementsAtEvent(chart, event))
+      }
+
+      return {
+        chartRef,
+        args,
+        onClick
+      }
+    }
+  }
+}
+
+Events.args = {
+  id: 'bar-chart',
+  type: 'bar',
+  width: 400,
+  height: 400,
+  ...barChartConfig
+}