Develop Reference

How to set action on slice-click Doughnut in Chart.js

I've been trying to add chart.js to my Django Project, which worked pretty fine so far. I made a doughnut-chart with two slices. Now i want to have each of those slices to have seperate actions on click, like for example redirecting to new side.
These are my chart settings:
var config = {
type: 'doughnut',
data: {
datasets: [{
data: {{ data|safe }}, // Error because django and js are being mixed
backgroundColor: [
'#ff0000', '#008000'
],
label: 'Population'
}],
labels: {{ labels|safe }}
},
options: {
responsive: true
}
};
And this is the rendering and my function to make the actions on click:
window.onload = function() {
var ctx = document.getElementById('pie-chart').getContext('2d');
var myPieChart = new Chart(ctx, config);
$('#myChart').on('click', function(event) {
var activePoints = myPieChart.getElementsAtEvent(event)
if(activePoints[0]){
console.log("Helo 1")
}
else {
console.log("helo 2")
}
})
};
I saw my solution on other pages, but it doesn't work at all. Am I missing something? If yes could you please help?

getElementAtEvent has been replaced with chart.getElementsAtEventForMode in Chart.js v3 (see 3.x Migration Guide).
Please take a look at below runnable code and see how it works now:
const pieChart = new Chart("myChart", {
type: 'pie',
data: {
labels: ["Red", "Blue", "Yellow"],
datasets: [{
data: [8, 5, 6],
backgroundColor: ["#FF6384", "#36A2EB", "#FFCE56"],
}]
},
options: {
onClick: evt => {
var elements = pieChart.getElementsAtEventForMode(evt, 'index', { intersect: true }, false);
var index = elements[0].index;
console.log(pieChart.data.labels[index] + ': ' + pieChart.data.datasets[0].data[index]);
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.9.1/chart.min.js"></script>
<canvas id="myChart"></canvas>

Storing Highcharts in array issue

I am plotting a number of highcharts dynamically in a loop and pushing each highchart to an array. So that while clicking on an external button, I can export the charts. But while pushing charts to array, only the last entry is properly set with options.
i had a reference to a fiddle that suggests to clone the options. [https://jsfiddle.net/ndb21y1w/][2]
https://www.highcharts.com/forum/viewtopic.php?t=38574
The fiddle have same series data plotted on all the charts. How to solve this if the data is different for each chart populated. Thanks for any help in advance.
Adding more clarity to question :
The data is populated dynamically in loop. My code logic is like:
counter i;
setInterval(function() {
//logic to populated data...
//It is a multiline chart, so three sets of arrays are populated.
//filling data1[], data2[] and data3[] .
drawChart(data1, data2, data3);
if(condition true) clearInterval();
i++;
});
drawChart(data1, data2, data3) {
var chart = new Highcharts.Chart({
title: {
text: "title",
},
xAxis: {
categories: [1,2,3,4...],
},
series: [{
type: 'line',
data: data1,
}, {
type: 'line',
data: data2,
}, {
type: 'line',
data: data3,
},
});
chartArray.push(chart);
}
This chartArray is where I mentioned to get the last entry only properly.

To create a chart you have to pass an HTML element that will be a chart container. In your code that what's missing. Check the demo I have prepared to reproduce this issue: https://jsfiddle.net/BlackLabel/c60y1t2v/
Code:
var chartArray = [],
counter = 1,
dataArr = [
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
],
containers = document.getElementById('containers');
function drawChart(data) {
var cnt = document.createElement('div'),
cntId = 'container' + counter++,
chart;
cnt.setAttribute('id', cntId);
containers.appendChild(cnt);
chart = new Highcharts.Chart(cntId, {
title: {
text: "title",
},
xAxis: {
categories: [1, 2, 3, 4],
},
series: [{
type: 'line',
data: data,
}]
});
return chart;
}
dataArr.forEach(function(data) {
var chart = drawChart(data);
chartArray.push(chart);
});

You need to define options each time you use a new chart. Reinitialize the OriginalOptions every time you create a new chart.
const options = [...Array(5)].map(() => {
const originalOptions = {
series: [{
data: [], // some random data
type: 'column'
}]
}
return Object.assign(originalOptions)
})
Fiddle
Updated:
For dynamically repopulating the chart, you have to initialize an empty chart and then add new series + redraw whenever your data is populated.
Your redraw function will look something like this:
var i = 0;
var data = [];
var chart = new Highcharts.Chart('container',{
series: []
});
var interval = setInterval(function() {
i++;
data[i] = [i*10 + 1, i*10+2, i*10+3];
drawChart(data[i]);
if(i > 2) clearInterval(interval);
},1000);
function drawChart(data) {
var series = {
type: 'line',
data: data
}
chart.addSeries(series, false);
chart.redraw();
}
See Updated Fiddle

To Print HTML as PDF you can use this software "wkhtmltopdf"
in Linux you need to use this command :
sudo apt-get install wkhtmltopdf
There are many library based on "wkhtmltopdf" in many languages so you can use it.
Library for PHP : https://github.com/mikehaertl/phpwkhtmltopdf

Store chart options in Array then map over to Initialize Highchart for each options.
var chartArray = [];
function drawChart(data1, data2, data3, i) {
// Create container for charts
const el = document.createElement('div');
document.body.appendChild(el).setAttribute("id", "container"+i);
// Create charts
var chart = new Highcharts.chart(el, {
series: [{
type: 'line',
data: data1,
}, {
type: 'line',
data: data2,
}, {
type: 'line',
data: data3,
}]
});
chartArray.push(chart);
console.log(chartArray);
}
var counter = 0;
var delayTime = 2000;
var timer = setInterval(function(){
var data1 = [30, 70, 50];
var data2 = [40, 70, 60];
var data3 = [10, 90, 20];
drawChart(data1, data2, data3, counter);
if(counter == 2){
clearInterval(timer);
}
counter++;
},delayTime);
<script src="https://code.highcharts.com/highcharts.js"></script>

How can I plot data from an external JSON file to a chart.js graph?

I would like to chart data from an external JSON file using chart.js. As an example, the json file here lists movies ("title") and ratings ("rt_score"). I'd like to be able to show each movie and its rating without including the static JSON in the .js file, but rather using the $.ajax call method to refer to the /films endpoint.
I'd like to have:
labels: labelsVariable
data: dataVariable
Here is a fiddle with the setup so far with static data.
Here's my HTML:
<body>
<canvas id="myChart" width="400" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.8.0/Chart.min.js">
</script>
</body>
Here's the js that successfully generates a bar chart like I want, but with static data in "labels" and "data" instead of referencing the JSON file.
var ctx = document.getElementById('myChart');
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Castle in the Sky', 'Grave of the Fireflies'],
datasets: [{
label: 'rating',
data: [95, 97],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
Instead of using the static data and labels, how can I reference the external JSON file using the $.ajax call method?
Based on what I've read, I may have to use "map" to break down the objects into arrays that contain labels and data?
Thank you in advance.

I think you are looking for Ajax request to fill your chart.
function getRandomIntInclusive(min, max) {
min = Math.ceil(min);
max = Math.floor(max);
return Math.floor(Math.random() * (max - min + 1)) + min;
}
var ctx_live = document.getElementById("mycanvas");
var myChart = new Chart(ctx_live, {
type: 'bar',
data: {
labels: [],
datasets: [{
data: [],
borderWidth: 1,
borderColor:'#00c0ef',
label: 'liveCount',
}]
},
options: {
responsive: true,
title: {
display: true,
text: "Chart.js - Dynamically Update Chart Via Ajax Requests",
},
legend: {
display: false
},
scales: {
yAxes: [{
ticks: {
beginAtZero: true,
}
}]
}
}
});
var postId = 1;
var getData = function() {
$.ajax({
url: 'https://jsonplaceholder.typicode.com/posts/' + postId + '/comments',
success: function(data) {
myChart.data.labels.push("Post " + postId++);
myChart.data.datasets[0].data.push(getRandomIntInclusive(1, 25));
// re-render the chart
myChart.update();
}
});
};
setInterval(getData, 3000);
see live example here.

Load the json chart data dynamically and set it when you are creating the graph. There are many ways you can load the chart json data. However, I believe the JQuery getJSON function is more relevant to you.
$.getJSON( "chartdata/test.json", function( data ) {
var myChart = new Chart(ctx, {
type: 'bar',
data: data,
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
}

I figured it out. Here's what worked. I had to use .map to set up the data properly inside variables and then use those variables as data and labels.
function renderChart(data, labels) {
var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: labels,
datasets: [{
label: 'This week',
data: data,
}]
},
});
}
function getChartData() {
$("#loadingMessage").html('<img src="./giphy.gif" alt="" srcset="">');
$.ajax({
url: "https://ghibliapi.herokuapp.com/films",
success: function (result) {
var data = result.map(x=>x.rt_score);
var labels = result.map(x=>x.title);
renderChart(data, labels);
console.log(data);
},
});
$("#renderBtn").click(
function () {
getChartData();
});

Pushing data from json to Chart.js labels and data

I am using the Chart.js lib to make charts.
I have a json array that I am getting from a database.
Here is the console log of it: Data
I need to get the address, speed, and speed limit for every element in the list and use it in a chart.
My current code is as follows:
function ShowChart() {
var popCanvas = document.getElementById("speedLimitsChart");
console.dir(speeddata);
var labels = speeddata.map(function (e) {
return e.Adress;
});
var speed = speeddata.map(function (e) {
return e.Speed;
});
var speedlimits = speeddata.map(function (e) {
return e.SpeedLimits;
});
console.dir(labels);
var barChart = new Chart(popCanvas, {
type: 'bar',
data: {
datasets: [{
label: 'Speed',
data: speed,
backgroundColor: '#1E90FF'
}, {
label: 'Speed Limits',
data: speedlimits,
backgroundColor: '#B22222',
type: 'line'
}],
},
labels: labels
});
}
But in the result I only have the first element in my chart, and there are no labels.
Here is the output screen: Chart
I checked speed, speedlimits and labels and all of them have 2 elements. Can you please advise where my problem might be?

I found where is my problem
I need to write labels inside of data
Like this
var barChart = new Chart(popCanvas, {
type: 'bar',
data: {
labels: labels ,
datasets: [{
label: 'Speed',
data: speed,
backgroundColor: '#1E90FF'
}, {
label: 'Speed Limits',
data: speedlimits,
backgroundColor: '#B22222',
type: 'line'
}],
},
});

Growing chart value - chart.js

I want to do so the chart value increases itself by 1 each second. How can I achieve that? I tried setting a counter variable and then increasing it every second but it didn't work dynamically for some reason.
var myChart = new Chart(ctx, {
type: 'line',
data: {
datasets: [{
label: 'Crash line',
data: [0, 1], //1 here needs to be increased so the graphs grows up
backgroundColor: [
'rgba(108, 170, 91, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)'
],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});

Check out this chart.js documention and chart.js update documention.
You need to use the chart.update method as so:
var options = //chart.js option object
var ctx = document.getElementById('chartJSContainer').getContext('2d');
var chart = new Chart(ctx, options);
var somefunc = function(chart){
var chartDatasetLength = chart.data.datasets[0].data.length;
for(var i = 0; i < chartDatasetLength; i++){
chart.data.datasets[0].data[i] += 1;
}
chart.update();
}
setInterval(somefunc, 1000, chart);
A working jsfiddle demo.