I have two HTML buttons, each linked to a specific JavaScript function. The first button triggers a function codded like so:
function add() {
var newScript = document.createElement("script");
newScript.src = "https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js";
document.head.appendChild(newScript);
}
The second button triggers the following function:
function draw() {
const ctx = document.getElementById('myChart').getContext('2d');
const myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255, 99, 132, 1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
y: {
beginAtZero: true
}
}
}
});
In function number 2, I am using a sample from www.chartjs.org. To work, it needs the page to have loaded the script referred to in the first function.
After clicking on the button 1 then on the button 2, I am expecting to see in my head element a script element, src=https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js, which I do see, via the browser console.
On my page, I am expecting to see (after clicking on my second button) a graph, produced by the ChartJS code. This very element is missing. Instead, I have an error in my console, saying: 'Chart is not defined at HTMLButtonElement.draw'
Why do I have this error? Why is my chart not showing up?
Thank you for stopping by :) (y)
One hacky solution is to just include the entire script in your function. i.e.
function add() {
/*!
* Chart.js v2.9.4
* https://www.chartjs.org
* (c) 2020 Chart.js Contributors
* Released under the MIT License
*/
//The entire contents of https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.min.js pasted here
}
Just add html script element, before the your script is evaluated.
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<script>
function draw() {
// your draw function
}
</script>