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Below is a working example that demonstrates modifying and updating the chart when clicking a button. Your addData
function is a little odd in that it adds data at index 7, but the dataset only has keys 0-5, so this causes an extra blank data point to be inserted at index 6.
In case this isn’t what you intended, I added some extra functions (pushData
and popData
) to show adding and removing from the end of a dataset as that’s a quite common requirement (and therefore documented).
// same as original function; inserts or updates index 7.
function addData(e) {
myBarChart.data.labels[7] = "Ekologisk palmolja";
myBarChart.data.datasets[0].data[7] = 14;
myBarChart.update();
}
// requested function; removes index 7.
function removeData(e) {
myBarChart.data.labels.splice(7, 1);
myBarChart.data.datasets[0].data.splice(7, 1);
myBarChart.update();
}
// example of how to add data point to end of dataset.
function pushData(e) {
myBarChart.data.labels.push("Ekologisk palmolja");
myBarChart.data.datasets[0].data.push(14);
myBarChart.update();
}
// example of how to remove data point from end of dataset.
function popData(e) {
myBarChart.data.labels.pop();
myBarChart.data.datasets[0].data.pop();
myBarChart.update();
}
// set listeners on buttons
document.getElementById('add1').addEventListener('click', addData);
document.getElementById('remove1').addEventListener('click', removeData);
document.getElementById('add2').addEventListener('click', pushData);
document.getElementById('remove2').addEventListener('click', popData);
Chart.defaults.global.defaultFontColor = 'grey';
Chart.defaults.global.defaultFontSize = 16;
let myBarChart = new Chart(document.getElementById('chart'), {
type: 'bar',
data: {
labels: ["2012", "2013", "2014", "2015", "2016", "2017"],
datasets: [{
label: "Miljoner ton",
fill: true,
lineTension: 0.1,
backgroundColor: "rgba(0,255,0,0.4)",
borderColor: "green", // The main line color
borderCapStyle: 'square',
pointBorderColor: "white",
pointBackgroundColor: "green",
pointBorderWidth: 1,
pointHoverRadius: 8,
pointHoverBackgroundColor: "yellow",
pointHoverBorderColor: "green",
pointHoverBorderWidth: 2,
pointRadius: 4,
pointHitRadius: 10,
data: [56.38, 59.3, 61.81, 58.83, 52.32, 66.86],
spanGaps: true
}]
},
options: {
maintainAspectRatio: false,
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
},
title: {
fontSize: 18,
display: true,
text: 'Källa: Globallife.org',
position: 'bottom'
}
}
});
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.min.js"></script>
<canvas id="chart"></canvas>
<button id="add1">Add index 7</button>
<button id="remove1">Remove index 7</button>
<button id="add2">Add to end</button>
<button id="remove2">Remove from end</button>
Source:stackexchange.com