chartjs-plugin-chart2music

chartjs-plugin-chart2music connects Chart.js charts to Chart2Music, providing keyboard navigation, screen-reader output, and interactive data sonification. Focus a chart to explore its data with the keyboard; the active data point is also highlighted on the visual chart.

This plugin is in beta. The supported chart types and integration points are listed below.

Install and use

npm install chart.js chartjs-plugin-chart2music

Register the plugin globally:

import Chart from "chart.js/auto";
import chart2music from "chartjs-plugin-chart2music";

Chart.register(chart2music);

new Chart(canvasElement, {
    type: "bar",
    data: {
        labels: ["Q1", "Q2", "Q3", "Q4"],
        datasets: [{label: "Revenue", data: [1, 4, 2, 8]}]
    }
});

Or add it to one chart only:

new Chart(canvasElement, {
    type: "bar",
    data: {
        datasets: [{data: [1, 4, 2, 8]}]
    },
    plugins: [chart2music]
});

When no cc element is supplied, the plugin creates a caption element immediately after the canvas. Supply your own element when you need to control where the Chart2Music output appears.

Plugin options

Configure the plugin through options.plugins.chartjs2music:

new Chart(canvasElement, {
    type: "bar",
    data: {
        labels: ["Q1", "Q2", "Q3", "Q4"],
        datasets: [{label: "Revenue", data: [1, 4, 2, 8]}]
    },
    options: {
        plugins: {
            chartjs2music: {
                cc: outputElement,
                lang: "en",
                axes: {
                    x: {label: "Quarter"},
                    y: {
                        label: "Revenue",
                        format: (value) => `$${value.toLocaleString()}`
                    }
                },
                options: {
                    enableSound: true,
                    onFocusCallback: (point) => console.log(point),
                    onSelectCallback: ({point}) => console.log(point)
                },
                errorCallback: console.error
            }
        }
    }
});

Available plugin options:

• cc: Element that receives Chart2Music's accessible chart caption. Optional.
• lang: Chart2Music language. Supported values include en, de, es, fr, and it; default is en.
• axes: Chart2Music axis configuration, including labels and value formatters.
• audioEngine: A custom Chart2Music audio engine.
• options: Chart2Music interaction options such as enableSound, onFocusCallback, and onSelectCallback.
• errorCallback: Receives errors while the plugin initializes or updates a chart.

Supported charts

The plugin supports Chart.js bar, line, pie, doughnut, polar area, and scatter charts, including mixed bar/line configurations. It also supports:

• Box plots from @sgratzl/chartjs-chart-boxplot.
• Matrix plots from chartjs-chart-matrix.
• Word clouds from chartjs-chart-wordcloud.
• Chart titles, axis titles, minimum and maximum values, linear and logarithmic axes, custom axis formatting, dataset visibility, and chart data updates.

Visual-only Chart.js settings such as color, padding, and line thickness do not affect the sonification. Advanced Chart.js parsing configurations and nonstandard axis identifiers are not currently supported.

Future support

Planned support includes:

• Chart subtitles.
• Radar plots.
• Error bars via chartjs-chart-error-bars.
• Parallel coordinate plots via chartjs-chart-pcp.
• Zoom interactions via chartjs-plugin-zoom.

Examples and Storybook

The repository includes runnable chart configurations under stories/charts, covering the supported chart types and plugin integrations. A Storybook catalogue exposes these examples as Bar, Line, Multi-chart, Distribution, Circular, Scatter, Matrix, Word cloud, and Options stories.

npm run storybook

Build the static Storybook site with:

npm run build-storybook

More examples are available in the CodePen collection.

Development

npm test
npm run build
npm run depcheck