Chart.js/docs/charts/area.md
L M 18e3bc0624 Allow filling above and below with different colors (#6318)
Two colors allowed : first one to fill above the target, second to fill below
Tests added
Docs edited
2019-11-21 13:48:31 -05:00

3.3 KiB

Area Charts

Both line and radar charts support a fill option on the dataset object which can be used to create area between two datasets or a dataset and a boundary, i.e. the scale origin, start or end (see filling modes).

Note: this feature is implemented by the filler plugin.

Filling modes

Mode Type Values
Absolute dataset index 1 number 1, 2, 3, ...
Relative dataset index 1 string '-1', '-2', '+1', ...
Boundary 2 string 'start', 'end', 'origin'
Disabled 3 boolean false

1 dataset filling modes have been introduced in version 2.6.0
2 prior version 2.6.0, boundary values was 'zero', 'top', 'bottom' (deprecated)
3 for backward compatibility, fill: true (default) is equivalent to fill: 'origin'

Example

new Chart(ctx, {
    data: {
        datasets: [
            {fill: 'origin'},      // 0: fill to 'origin'
            {fill: '+2'},          // 1: fill to dataset 3
            {fill: 1},             // 2: fill to dataset 1
            {fill: false},         // 3: no fill
            {fill: '-2'}           // 4: fill to dataset 2
        ]
    }
});

If you need to support multiple colors when filling from one dataset to another, you may specify an object with the following option :

Param Type Description
target number, string, boolean The accepted values are the same as the filling mode values, so you may use absolute and relative dataset indexes and/or boundaries.
above Color If no color is set, the default color will be the background color of the chart.
below Color Same as the above.

Example

new Chart(ctx, {
    data: {
        datasets: [
            {
              fill: {
                target: 'origin',
                above: 'rgb(255, 0, 0)',   // Area will be red above the origin
                below: 'rgb(0, 0, 255)'    // And blue below the origin
              }
            }
        ]
    }
});

Configuration

Option Type Default Description
plugins.filler.propagate boolean true Fill propagation when target is hidden.

propagate

propagate takes a boolean value (default: true).

If true, the fill area will be recursively extended to the visible target defined by the fill value of hidden dataset targets:

Example

new Chart(ctx, {
    data: {
        datasets: [
            {fill: 'origin'},   // 0: fill to 'origin'
            {fill: '-1'},       // 1: fill to dataset 0
            {fill: 1},          // 2: fill to dataset 1
            {fill: false},      // 3: no fill
            {fill: '-2'}        // 4: fill to dataset 2
        ]
    },
    options: {
        plugins: {
            filler: {
                propagate: true
            }
        }
    }
});

propagate: true:

  • if dataset 2 is hidden, dataset 4 will fill to dataset 1
  • if dataset 2 and 1 are hidden, dataset 4 will fill to 'origin'

propagate: false:

  • if dataset 2 and/or 4 are hidden, dataset 4 will not be filled