CODEWITHSUNDEEP
javascripthtmlcsschart.js
Mohammad Samdi
Mohammad Samdi

Reputation: 111

Draw a horizontal bar chart from right to left

I am creating a horizontal bar chart in Chart.js as you can see in this jsfiddle.

I want to change the chart direction so that it draws from right to left. I tried dir = rtl and in CSS direction=rtl but they don't work.

This is what I want: expected chart output

Upvotes: 3

Views: 4399

Answers (2)

Laam55
Laam55

Reputation: 31

You can do it with this in Chart.js v4. Its same keyword in lower version:

var options = {
  scales: {
    x: { reverse: true },
  },
}

Docs: https://www.chartjs.org/docs/latest/api/interfaces/CoreScaleOptions.html

Upvotes: 3

timclutton
timclutton

Reputation: 13004

I can't find a native way in the documentation to do this, but you can do it via the fairly simple workaround of negating the data so that Chart.js draws negative values:

  1. invert the values in the dataset:

    data.datasets[0].data.map((currentValue, index, array) => {
  array[index] = currentValue * -1;
});

  2. right-align the y-axis:

    scales: {
  yAxes: [{
    position: 'right'
    ...

  3. reformat tooltips for display:

    options = {
  tooltips: {
  callbacks: {
    label: function(tooltipItem, data) {
      var label = data.datasets[tooltipItem.datasetIndex].label || '';

      if (label) {
        label += ': ';
      }
      label += tooltipItem.xLabel * -1;
      return label;
    }
  }
  ...

  4. reformat ticks for display:

    xAxes: [{
  ticks: {
    callback: function(value, index, values) {
      return value * -1;
    }
...

Here's a working example:

var data = {
  labels: ["x1", "x2", "x3", "x4", "x5"],
  datasets: [{
    label: "Actual",
    backgroundColor: 'rgba(0, 0, 255, 0.5)',
    borderWidth: 1,
    data: [40, 150, 50, 60, 70],
    yAxisID: "bar-y-axis1"
  }]
};

// invert the sign of each of the values.
data.datasets[0].data.map((currentValue, index, array) => {
  array[index] = currentValue * -1;
});

var options = {
  tooltips: {
    callbacks: {
      label: function(tooltipItem, data) {
        var label = data.datasets[tooltipItem.datasetIndex].label || '';

        if (label) {
          label += ': ';
        }
        label += tooltipItem.xLabel * -1; // invert the sign for display.
        return label;
      }
    }
  },
  scales: {
    yAxes: [{
      id: "bar-y-axis1",
      categoryPercentage: 0.5,
      barPercentage: 0.5,
      position: 'right' // right-align axis.
    }],

    xAxes: [{
      id: "bar-x-axis1",
      stacked: false,
      ticks: {
        callback: function(value, index, values) {
          return value * -1; // invert the sign for tick labelling.
        },
        beginAtZero: true
      }
    }]
  }
};

var ctx = document.getElementById("canvas").getContext("2d");
var myBarChart = new Chart(ctx, {
  type: 'horizontalBar',
  data: data,
  options: options
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.8.0/Chart.min.js"></script>
<canvas id="canvas"></canvas>

Upvotes: 9

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