sambatlim/chartjs-gauge

Gauge chart for Chart.js

chartjs-gauge

Simple gauge chart for Chart.js

Samples

• Gauge Chart
• Gauge Chart with datalabels plugin
• Gauge Chart with datalabels plugin displaying labels

Install

• yarn install: yarn add chart.js chartjs-gauge
• npm install: npm install --save chart.js chartjs-gauge

Configuration Options

The gauge chart is based on the Doughnut type. It defines the following additional configuration options. These options are merged with the global chart configuration options, Chart.defaults.global, to form the options passed to the chart.

Name	Type	Default	Description
needle.radiusPercentage	number	2	Needle circle radius as the percentage of the chart area width.
needle.widthPercentage	number	3.2	Needle width as the percentage of the chart area width.
needle.lengthPercentage	number	80	Needle length as the percentage of the interval between inner radius (0%) and outer radius (100%) of the arc.
needle.color	Color	'rgba(0, 0, 0, 1)'	The color of the needle.
valueLabel.display	boolean	true	If true, display the value label.
valueLabel.formatter	function	Math.round	Returns the string representation of the value as it should be displayed on the chart.
valueLabel.fontSize	number	undefined	The font size of the label.
valueLabel.color	Color	'rgba(255, 255, 255, 1)'	The text color of the label.
valueLabel.backgroundColor	Color	'rgba(0, 0, 0, 1)'	The background color of the label.
valueLabel.borderRadius	number	5	Border radius of the label.
valueLabel.padding.top	number	5	Top padding of the label.
valueLabel.padding.right	number	5	Right padding of the label.
valueLabel.padding.bottom	number	5	Bottom padding of the label.
valueLabel.padding.left	number	5	Left padding of the label.
valueLabel.bottomMarginPercentage	number	5	Bottom margin as the percentage of the chart area width.

Default Options

It is common to want to apply a configuration setting to all created gauge charts. The global gauge chart settings are stored in Chart.defaults.gauge. Changing the global options only affects charts created after the change. Existing charts are not changed.

For example, to configure all line charts with radiusPercentage = 5 you would do:

Chart.defaults.gauge.needle.radiusPercentage = 5;

Dataset Properties

The gauge chart requires a value to be specified for the dataset. This is used to draw the needle for the dataset.

Name	Type	Default	Description
value	number	undefined	Value used for the needle.
minValue	number	0	Used to offset the start value.

Example

var ctx = document.getElementById("canvas").getContext("2d");

var chart = new Chart(ctx, {
  type: 'gauge',
  data: {
    datasets: [{
      value: 0.5,
      minValue: 0,
      data: [1, 2, 3, 4],
      backgroundColor: ['green', 'yellow', 'orange', 'red'],
    }]
  },
  options: {
    needle: {
      radiusPercentage: 2,
      widthPercentage: 3.2,
      lengthPercentage: 80,
      color: 'rgba(0, 0, 0, 1)'
    },
    valueLabel: {
      display: true,
      formatter: (value) => {
        return '$' + Math.round(value);
      },
      color: 'rgba(255, 255, 255, 1)',
      backgroundColor: 'rgba(0, 0, 0, 1)',
      borderRadius: 5,
      padding: {
        top: 10,
        bottom: 10
      }
    }
  }
});

License

chartjs-gauge is available under the MIT license.