Guide to modifying the column color in Chart.js

Question

Guide to modifying the column color in Chart.js

Link to my codepen project: Check it out here

let ctx = document.getElementById('myChart').getContext('2d');
let chart = new Chart(ctx, {
  // Type of chart being created
  type: 'bar',

  // Data for the dataset
  data: {
    labels: ['January', 'February', 'March', 'April', 'May', 'June', 'July'],
    datasets: [{
      label: 'My First dataset',
      backgroundColor: 'rgb(255, 99, 132)',
      borderColor: 'rgb(255, 99, 132)',
      data: [0, -10, 35, 2, -19, 30, 15]
    }]
  },

  // Configuration options go here
  options: {}
});

<canvas id="myChart"></canvas>
<script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="ceada6afbcbae0a4bd8efce0f6e0fe">[email protected]</a>"></script>

I would like to change the color of a column when its value is 0 and adjust its position. Thank you.

The desired result looks like this: https://i.sstatic.net/MiFZN.png

javascript chart.js

Answer 1

Answer №1

I believe I have resolved your issue:

function modifyChart(chart){
    let val = 2;
    let updatedValues = [];
    chart.data.datasets[0].data.forEach((e,i)=>{
    if(e===0){
      updatedValues.push('green');
      chart.data.datasets[0].data[i] = val;
      chart.data.datasets.push({data:
        Array.from({length:chart.data.datasets[0].data.length},function(el,j){
            if(i===j) return -val
        })})
    } else {
        updatedValues.push(chart.data.datasets[0].backgroundColor)
    }

  })
  chart.data.datasets.forEach(e=>{
    e.backgroundColor = updatedValues;
  })

  chart.update()
}

Try it out for yourself on this fiddle link: https://jsfiddle.net/7Lbjmw6r/

Answer 2

I believe I have resolved your issue:

function modifyChart(chart){
    let val = 2;
    let updatedValues = [];
    chart.data.datasets[0].data.forEach((e,i)=>{
    if(e===0){
      updatedValues.push('green');
      chart.data.datasets[0].data[i] = val;
      chart.data.datasets.push({data:
        Array.from({length:chart.data.datasets[0].data.length},function(el,j){
            if(i===j) return -val
        })})
    } else {
        updatedValues.push(chart.data.datasets[0].backgroundColor)
    }

  })
  chart.data.datasets.forEach(e=>{
    e.backgroundColor = updatedValues;
  })

  chart.update()
}

Try it out for yourself on this fiddle link: https://jsfiddle.net/7Lbjmw6r/

Answer 3

Answer №2

Hey there! To set the background color for each dataset in a chart, you need to provide an array of colors within the backgroundColor parameter. Take a look at this example:

var labels = ["A", "B", "C", "D", "E", "F", "G"];
var data = [35, 45, 60, 70, 55, 40, 30];
var background_colors = [];
for (var i = 0; i < labels.length; i++) {
   background_colors.push(getRandomColor());
}

var barChartData = {
  labels: labels,
  datasets: [{
    label: "My Data",
    fill: true,
    borderColor: "rgba(255,99,132,1)",
    backgroundColor: background_colors,
    data: data
  }]
};

Give it a try and let me know if it works for you!

Answer 4

Hey there! To set the background color for each dataset in a chart, you need to provide an array of colors within the backgroundColor parameter. Take a look at this example:

var labels = ["A", "B", "C", "D", "E", "F", "G"];
var data = [35, 45, 60, 70, 55, 40, 30];
var background_colors = [];
for (var i = 0; i < labels.length; i++) {
   background_colors.push(getRandomColor());
}

var barChartData = {
  labels: labels,
  datasets: [{
    label: "My Data",
    fill: true,
    borderColor: "rgba(255,99,132,1)",
    backgroundColor: background_colors,
    data: data
  }]
};

Give it a try and let me know if it works for you!

Guide to modifying the column color in Chart.js

Answer №1

Answer №2

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