1π
β
Iβve managed to find the answer to this question, basically by taking apart the bubble chart example from the chartjs-plugin-datalabels plugin.
Below is a working example. Pay attention to the section in options that says βpluginβ.
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.0/Chart.bundle.js"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-plugin-datalabels"></script>
<div class="container" >
<h2>Chart.js β Line Chart Demo</h2>
<div>
<canvas id="myChart"></canvas>
</div>
</div>
<script>
var ctx = document.getElementById('myChart').getContext('2d');
ctx.height = 1000;
var myChart = new Chart(ctx, {
type: 'bubble',
data: {
datasets: [
{
label: 'Your Data',
data: [
{x: 78.7, y: 0, r: 10, name: "Performance"}
],
backgroundColor: "rgba(153,255,51,0.6)"
},
{
label: 'Average',
data: [
{x: 100.7, y: 0, r: 10, name: "Performance"} // The labe needs to be
],
backgroundColor: "rgba(255,0,128,0.6)"
}
]
},
options: {
plugins: { // Look at this bit
datalabels: {
anchor: function(context) {
var value = context.dataset.data[context.dataIndex];
return value.x < 50 ? 'end' : 'center';
},
align: function(context) {
var value = context.dataset.data[context.dataIndex];
return value.x < 50 ? 'end' : 'center';
},
color: function(context) {
var value = context.dataset.data[context.dataIndex];
return value.x < 50 ? context.dataset.backgroundColor : 'white';
},
font: {
weight: 'bold'
},
formatter: function(value) {
return Math.round(value.x);
},
offset: 2,
padding: 0
}
},
maintainAspectRatio: false,
scales: {
yAxes: [{
id: 'first-y-axis',
type: 'linear',
ticks: {
min: 0,
max: 1,
stepSize: 1,
display: false
},
gridLines: {
display: false,
drawBorder: false
}
}],
xAxes: [{
ticks: {
min: 50, // Controls where axis starts
max: 120 // Controls where axis finishes
},
gridLines: {
display: false,
lineWidth: 3 // Width of bottom line
}
}]
}
}
});
</script>
0π
If all you want to do is changing the label, there is an easier solution. From the docs of chartjs-plugin-datalabels:
Data values are converted to string (
'' + value
). If value is an object, the following rules apply first:
value = value.label
if defined and not nullelse
value = value.r
if defined and not nullelse
value = 'key[0]: value[key[0]], key[1]: value[key[1]], ...'
Therefore, it is sufficient to specify a label
in your data points:
data: [{ x: 78.7, y: 0, r: 10, name: "Performance", label: `${Math.round(x)}` }],
Source:stackexchange.com