I have been trying to create a scatter graph using chart.js, and using data from a JSON object I am fetching from a public api, however my graph is not being created but I am not getting any errors on my console therefore I am unsure as to where the problem is.
This is the structure of my JSON object
0:{
first_name: "Shkodran"
form: "2.3"
points_per_game: "3.2"
now_cost: 51
second_name: "Mustafi"
web_name: "Mustafi"
minutes: 620
goals_scored: 0
assists: 2
clean_sheets: 2
goals_conceded: 9
}
Each entry is a different player and there are 628 entries.
Below is the code I am using
Fetching the public api and parsing the response
var request = new XMLHttpRequest()
var json;
request.open('GET','https://cors- anywhere.herokuapp.com/https://fantasy.premierleague.com/api/bootstrap-static/' , true)
request.onload = function() {
if (request.status >= 200 && request.status < 400) {
json = JSON.parse(this.response);
}
console.log(json);
}
request.send();
Generating the datasets for the scatter graph as I want my graph to be x:now_cost and y:points_per_game.
Creating the chart using chart.js
if (document.readyState === 'complete') {
function generateData() {
var data=[];
json.elements.forEach(elements => {
data.push({
x: elements.now_cost,
y: points_per_game
});
});
return data;
}
var ctx = document.getElementById('chart1').getContext('2d');
var scatterChart = new Chart(ctx, {
type: 'scatter',
data: {
dataset: [{
data: generateData()
}]
},
options: {
title: {
display: true,
text: 'Cost vs Points Per Game Chart'
},
scales: {
xAxes: [{
title:{
display:true,
text: 'Cost'
},
type: 'linear',
position: 'bottom'
}],
yAxes: [{
title:{
display:true,
text: 'Points Per Game'
},
type: 'linear',
position: 'bottom'
}]
}
}
});
}
Your data is not of valid JSON format, individual properties need to be separated by a comma each. There's also an error inside the generateData function with the assignment to the y property. It should be rewritten as follows:
function generateData() {
var data = [];
json.elements.forEach(element => {
data.push({
x: element.now_cost,
y: element.points_per_game
});
});
return data;
}
Or you could even get rid of this function generateData and assign data directly as follows:
dataset: [{
data: json.elements.map(e => ({ x: e.now_cost, y: e.points_per_game }))
}]
So what I have is a chart in which I have events function which loads data for multiple sets.
suppose I have data of 3000 points. The first data set renders the first 1000 points and after that second data set renders 2000 points.
for which I am calling my 'events' function .
but the problem arises that after showing the first 1000 set of data. The chart starts from the begining.
I don't want that.
That's why I need a solution so that my Highchart's chart render only once and the event function loads continuously.
Here's a snip of my Highchart's js
Highcharts.chart("chartcontainer", { // make thsi chart load only once.
chart: {
type: 'line',
animation: Highcharts.svg, // don't animate in old IE
marginRight: 10,
//Load this event function as the data updates
events: {
load: function() {
var series = this.series[0],
chart = this;
setInterval(function() {
//some logic regarding the chart
//..
v = {
y: y,
x: x
};
console.log("V value", v);
series.addSeries(v, false, true);
counter++;
localcounter++;
} else
{
oldcounter=counter;
flagToreload=1;
}
}, 1000/130);
setInterval(function() {
chart.redraw(false);
}, 100);
}
}
},
time: {
useUTC: false
},
title: {
text: 'Live random data'
},
xAxis: {
type: 'Value',
gridLineWidth: 1
},
yAxis: {
title: {
text: 'Value'
},
plotLines: [{
value: 0,
width: 1,
color: '#808080'
}],
gridLineWidth: 1
},
tooltip: {
headerFormat: '<b>{series.name}</b><br/>',
pointFormat: '{point.x:%Y-%m-%d %H:%M:%S}<br/>{point.y:.2f}'
},
exporting: {
enabled: false
},
series: [{
animation: false,
name: 'Random data',
data: (function() {
// generate an array of random data
var data = [],
time = counter,
i;
for (i = -1000; i <= 0; i += 1) {
data.push([
counter,
null
]);
}
return data;
}())
}]
});
You can use:
addPoint method:
chart: {
events: {
load: function() {
var newData,
chart = this,
series = chart.series[0];
setInterval(function() {
newData = getRandomData();
newData.forEach(function(el) {
series.addPoint(el, false);
});
chart.redraw();
}, 2000);
}
}
}
Live demo: http://jsfiddle.net/BlackLabel/2a8qswhf/
API Reference: https://api.highcharts.com/class-reference/Highcharts.Series#addPoint
setData method:
chart: {
events: {
load: function() {
var newData,
chart = this,
combinedData,
series = chart.series[0];
setInterval(function() {
newData = getRandomData();
combinedData = series.userOptions.data.concat(newData);
series.setData(combinedData);
}, 2000);
}
}
}
Live demo: http://jsfiddle.net/BlackLabel/Lmsk8yw9/
API Reference: https://api.highcharts.com/class-reference/Highcharts.Series#setData
I'm using c3 js for generating categories bar chart
Here is code
var obj = {
size: {
height: 200,
},
bindto: '#grBarChart',
data: {
columns: data.columns,
type: "bar"
},
color: {
pattern: ['#c90000', '#008cba', '#FAAC3D','#427322', '#9ead9b', '#ffa500']
},
axis: {
x: {
type: 'category',
categories: data.categories,
label: {
text: 'Scanned Groups',
position: 'outer-center'
}
},
y: {
label: {
text: 'Count (Rules)',
position: 'outer-middle'
}
}
},
bar: {
width: {
ratio: 0.5,
}
},
grid: {
y: {
show: true
}
}
};
var chart = c3.generate(obj);
This code is generating the following graph
Now my problem is I'm not able to add click event on X Axis Category Names ( Logging 11, Data Protection 13 ...)
I referred C3 Documentation but not able to solve my problem.
Please give me your thought?
I was having some trouble when trying to dynamically populate bar chart in chart.js. I have two arrays, one for label, one for its price and both of them are already populated with the sorted data from firebase. Here is my code:
var ctx = document.getElementById('brandChart').getContext("2d");
var data = {
labels: [],
datasets: [{
data: [],
backgroundColor: [
"#424242",
]
}]
};
var options = {
layout: {
padding: {
top: 5
}
},
responsive: true,
legend: {
display: true,
position: 'bottom',
// disable legend onclick remove slice
onClick: null
},
animation: {
animateScale: true,
animateRotate: true
},
};
var opt = {
type: "horizontalBar",
data: data,
options: options
};
if (brandChart) brandChart.destroy();
brandChart = new Chart(ctx, opt);
// dynamically populate chart
for(var i = 0; i < labelData.length; i++){
brandChart.config.data.labels.push(labelData[i]);
}
for(var i = 0; i < priceData.length; i++){
brandChart.config.data.datasets[0].data.push(priceData[i]);
}
brandChart.update();
I managed to show all of them in bar chart, however, the result as such:
It is kind of squeeze between each labels if there are too many categories. Also, only the first bar has the color & the legends shown undefined. Any ideas how to solve these?
ɪꜱꜱᴜᴇ #1 - ꜱᴏʟᴜᴛɪᴏɴ
Add a callback for y-axis ticks, in your chart options :
options: {
scales: {
yAxes: [{
ticks: {
callback: function(t, i) {
if (!(i % 2)) return t;
}
}
}]
},
...
}
this will only show every other label on y-axis.
ɪꜱꜱᴜᴇ #2 - ꜱᴏʟᴜᴛɪᴏɴ
This is because, you have only one color in your backgroundColor array. If you want different color for each bar, then you need to populate this array with multiple color values.
Edit: as it seems form your updated question, you already kind of got the idea.
ɪꜱꜱᴜᴇ #3 - ꜱᴏʟᴜᴛɪᴏɴ
Define the label property for your dataset , like so :
datasets: [{
label: 'Legend Title', //<- define this
data: [],
backgroundColor: ["#424242", ]
}]
I've just started working with Chart.js, and I am getting very frustrated very quickly. I have my stacked bar chart working, but I can't get the click "events" to work.
I have found a comment on GitHub by nnnick from Chart.js stating to use the function getBarsAtEvent, even though this function cannot be found in the Chart.js documentation at all (go ahead, do a search for it). The documentation does mention the getElementsAtEvent function of the chart reference, but that is for Line Charts only.
I set an event listener (the right way) on my canvas element:
canv.addEventListener('click', handleClick, false);
...yet in my handleClick function, chart.getBarsAtEvent is undefined!
Now, in the Chart.js document, there is a statement about a different way to register the click event for the bar chart. It is much different than nnnick's comment on GitHub from 2 years ago.
In the Global Chart Defaults you can set an onClick function for your chart. I added an onClick function to my chart configuration, and it did nothing...
So, how the heck do I get the on-click-callback to work for my bar chart?!
Any help would be greatly appreciated. Thanks!
P.S.: I am not using the master build from GitHub. I tried, but it kept screaming that require is undefined and I was not ready to include CommonJS just so that I could use this chart library. I would rather write my own dang charts. Instead, I downloaded and am using the Standard Build version that I downloaded straight from the link at the top of the documentation page.
EXAMPLE: Here is an example of the configuration I am using:
var chart_config = {
type: 'bar',
data: {
labels: ['One', 'Two', 'Three'],
datasets: [
{
label: 'Dataset 1',
backgroundColor: '#848484',
data: [4, 2, 6]
},
{
label: 'Dataset 2',
backgroundColor: '#848484',
data: [1, 6, 3]
},
{
label: 'Dataset 3',
backgroundColor: '#848484',
data: [7, 5, 2]
}
]
},
options: {
title: {
display: false,
text: 'Stacked Bars'
},
tooltips: {
mode: 'label'
},
responsive: true,
maintainAspectRatio: false,
scales: {
xAxes: [
{
stacked: true
}
],
yAxes: [
{
stacked: true
}
]
},
onClick: handleClick
}
};
I managed to find the answer to my question by looking through the Chart.js source code.
Provided at line 3727 of Chart.js, Standard Build, is the method .getElementAtEvent. This method returns me the "chart element" that was clicked on. There is sufficent data here to determine what data to show in a drill-down view of the dataset clicked on.
On the first index of the array returned by chart.getElementAtEvent is a value _datasetIndex. This value shows the index of the dataset that was clicked on.
The specific bar that was clicked on, I believe, is noted by the value _index. In my example in my question, _index would point to One in chart_config.data.labels.
My handleClick function now looks like this:
function handleClick(evt)
{
var activeElement = chart.getElementAtEvent(evt);
..where chart is the reference of the chart created by chart.js when doing:
chart = new Chart(canv, chart_config);
The specific set of data that was selected by the click can therefore be found as:
chart_config.data.datasets[activeElement[0]._datasetIndex].data[activeElement[0]._index];
And there you have it. I now have a datapoint that I can build a query from to display the data of the bar that was clicked on.
AUGUST 7TH, 2021. UPDATE
There is now a method for what we are looking for. Take a look at here
Hi this is the click event under options which is getting values from x and y-axis
onClick: function(c,i) {
e = i[0];
console.log(e._index)
var x_value = this.data.labels[e._index];
var y_value = this.data.datasets[0].data[e._index];
console.log(x_value);
console.log(y_value);
}
I found this solution at https://github.com/valor-software/ng2-charts/issues/489
public chartClicked(e: any): void {
if (e.active.length > 0) {
const chart = e.active[0]._chart;
const activePoints = chart.getElementAtEvent(e.event);
if ( activePoints.length > 0) {
// get the internal index of slice in pie chart
const clickedElementIndex = activePoints[0]._index;
const label = chart.data.labels[clickedElementIndex];
// get value by index
const value = chart.data.datasets[0].data[clickedElementIndex];
console.log(clickedElementIndex, label, value)
}
}
}
You can use onClick like this.
var worstCells3GBoxChart = new Chart(ctx, {
type: 'bar',
data: {
labels: lbls,
datasets: [{
label: 'Worst Cells by 3G',
data: datas,
backgroundColor: getColorsUptoArray('bg', datas.length),
borderColor: getColorsUptoArray('br', datas.length),
borderWidth: 1
}]
},
options: {
legend: {
display: false
},
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
},
onClick: function (e) {
debugger;
var activePointLabel = this.getElementsAtEvent(e)[0]._model.label;
alert(activePointLabel);
}
}
});
Chartjs V3.4.1
This is what worked for me in v3, after looking at solutions for older versions:
const onClick = (event, clickedElements) => {
if (clickedElements.length === 0) return
const { dataIndex, raw } = clickedElements[0].element.$context
const barLabel = event.chart.data.labels[dataIndex]
...
}
raw is the value of the clicked bar.
barLabel is the label of the clicked bar.
You need to pass the onClick to the bar chart config:
const barConfig = {
...
options: {
responsive: true,
onClick,
...
}
}
Well done! This seems to return the data value being charted though, which in many cases might be possible to appear more than once, thus making it unclear what was clicked on.
This will return the actual data label of the bar being clicked on. I found this more useful when drilling down into a category.
chart_config.data.labels[activeElement[0]._index]
I was able to make this work in another way.
Might not be supported, but sometimes, I find that neither the label nor the value is adequate to get me the necessary information to populate a drill-through.
So what I did was add a custom set of attributes to the data:
var ctx = document.getElementById("cnvMyChart").getContext("2d");
if(theChart != null) {theChart.destroy();}
theChart = new Chart(ctx, {
type: typ,
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datakeys: ["thefirstone","thesecondone","thethirdone","thefourthone","thefifthone","thesixthone"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
...etc
Then when I need to push the drillthrough key into another ajax call, I was able to get it with this:
var theDrillThroughKey = theChart.config.data.datakeys[activePoints[0]._index];
So I'm really not sure that it's appropriate to be adding custom elements into the data for the Chart, but it's working so far in Chrome, IE and Firefox. I needed to be able to put more information into the drillthrough than I really wanted displayed.
Example of the full thing: https://wa.rrdsb.com/chartExamples
Thoughts?
I had the same problem with multiple datasets, and used this workaround:
var clickOnChart = function(dataIndex){
...
}
var lastHoveredIndex = null;
var chart_options = {
...
tooltips: {
...
callbacks: {
label: function(tooltipItem, chart) {
var index = tooltipItem.datasetIndex;
var value = chart.datasets[index].data[0];
var label = chart.datasets[index].label;
lastHoveredIndex = index;
return value + "€";
}
}
},
onClick:function(e, items){
if ( items.length == 0 ) return; //Clicked outside any bar.
clickOnChart(lastHoveredIndex);
}
}
Let's say that you declared a chart using a method like so:
window.myBar = new Chart({chart_name}, {
type: xxx,
data: xxx,
events: ["click"],
options: {
...
}
});
A good way of declaring onclick events would involve listening for the canvas click, like so:
({chart_name}.canvas).onclick = function(evt) {
var activePoints = myBar.getElementsAtEvent(evt);
// let's say you wanted to perform different actions based on label selected
if (activePoints[0]._model.label == "label you are looking for") { ... }
}
In the chart options for Chart.js v3.5.1 which is latest
Check below sample code
let enterpriseChartOptions = {
responsive:true,
maintainAspectRatio: false,
onClick: (c,i) => {
console.log('Get the underlying label for click,', c.chart.config._config.data.labels[i[0].index]);
},
plugins: {
title:{
text:'Enterprise Dashboard (Health Status of 10 stores) updated every 30 minutes',
fontSize:20
},
},
scales: {
x: {
display: true,
type: 'category',
position: 'right',
ticks: {
padding: 8,
},
},
y: {
display: true,
ticks: {
callback: function(val, index) {
// Show the label
return val < 1 ? "All good" : (val < 2 && val >=1) ? "Warning": val === 2 ? "Critical" : "";
},
//color: 'red',
stepSize: 1,
padding: 8
}
}
},
layout: {
padding: {
left: 20,
right: 20,
top: 25,
bottom: 0
}
},
};
var employeeDetailsCtx = document.getElementById("employee-details").getContext("2d");
var employee_details_data = {
labels: ["Late Present", "On Leave", "Training", "Tour"],
datasets: [{
label: "Officer",
backgroundColor: "#5A8DEE",
data: [
...
]
}, {
label: "Staff",
backgroundColor: "#4BC0C0",
data: [
...
]
}]
};
var myoption = {
tooltips: {
enabled: true
},
hover: {
animationDuration: 1
},
onClick: function (evt, i) {
var activePoint = employeeDetailsBarChart.getElementAtEvent(evt)[0];
var data = activePoint._chart.data;
var datasetIndex = activePoint._datasetIndex;
var label = data.datasets[datasetIndex].label;
var value = data.datasets[datasetIndex].data[activePoint._index];
e = i[0];
var x_value = this.data.labels[e._index];
console.log(x_value)
console.log(label)
console.log(value)
},
animation: {
duration: 1,
onComplete: function () {
var chartInstance = this.chart,
ctx = chartInstance.ctx;
ctx.textAlign = 'center';
ctx.fillStyle = "rgba(0, 0, 0, 1)";
ctx.textBaseline = 'bottom';
this.data.datasets.forEach(function (dataset, i) {
var meta = chartInstance.controller.getDatasetMeta(i);
meta.data.forEach(function (bar, index) {
var data = dataset.data[index];
ctx.fillText(data, bar._model.x, bar._model.y - 5);
});
});
}
}
};
var employeeDetailsBarChart = new Chart(employeeDetailsCtx, {
type: 'bar',
data: employee_details_data,
options: myoption
});