How to access all data in a function with ChartJs?

Question

Consider the following code.

 var chartData = { labels: ["January", "February", "March", "April", "May", "June"], datasets: [{ fillColor: "#79D1CF", strokeColor: "#79D1CF", data: [60, 80, 81, 56, 55, 40] }] }; var ctx = document.getElementById("myChart1").getContext("2d"); var myLine = new Chart(ctx, { type: "line", data: chartData, showTooltips: false, onAnimationComplete: function() { var ctx = this.chart.ctx; ctx.font = this.scale.font; ctx.fillStyle = this.scale.textColor ctx.textAlign = "center"; ctx.textBaseline = "bottom"; this.datasets.forEach(function(dataset) { dataset.points.forEach(function(points) { ctx.fillText(points.value, points.x, points.y - 10); }); }) } });

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.6.2/chart.min.js"></script> <canvas id="myChart1" height="300" width="500"></canvas>

Because I use the function in the onAnimationComplete in different graphs, I like to create a JavaScript file where I collect all the functions and use them. For example

var chart = new Chart(ctx, eval(config));

chart.options.animation.onComplete = function () {
    window["AnimationComplete1"](chart);
}

function AnimationComplete1(chart) {
    var ctx = chart.ctx;
    ctx.textAlign = "center";
    ctx.textBaseline = "bottom";

    chart.data.datasets.forEach(function (dataset) {
        dataset.points.forEach(function (points) {
            ctx.fillText(points.value, points.x, points.y - 10);
        });
    })
}

In this code, the problem is that in the function I don't have access to the point from the dataset from chart.data.datasets . Also, I don't have access to the scale for font and textColor .

Is there a way to access those values from a common function?

Answer 1

The Chart.js animation onComplete callback function must be defined inside the chart options .

options: {
  animation: {
    onComplete: ctx => {
      // do your stuff
    }
  }
}

Please take a look at your amended code below and see how it works.

 var chartData = { labels: ["January", "February", "March", "April", "May", "June"], datasets: [{ fillColor: "#79D1CF", strokeColor: "#79D1CF", data: [60, 80, 81, 56, 55, 40] }] }; new Chart('myChart1', { type: "line", data: chartData, options: { animation: { onComplete: ctx => { console.log(ctx.chart.data.datasets); console.log(ctx.chart.options.scales.x); } } } });

 <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.8.0/chart.min.js"></script> <canvas id="myChart1" height="300" width="500"></canvas>