Make Chart.js horizontal bar labels multi-line - javascript

Just wondering if there is any way to set the horizontal bar labels for y-axis using chart.js. Here is how I set up the chart:
<div class="box-body">
<canvas id="chart" style="position: relative; height: 300px;"></canvas>
</div>
Javascript:
var ctx = document.getElementById('chart').getContext("2d");
var options = {
layout: {
padding: {
top: 5,
}
},
responsive: true,
animation: {
animateScale: true,
animateRotate: true
},
};
var opt = {
type: "horizontalBar",
data: {
labels: label,
datasets: [{
data: price,
}]
},
options: options
};
if (chart) chart.destroy();
chart= new Chart(ctx, opt);
chart.update();
As you all can see, the first and third labels are too long and cut off. Is there a way to make the label multi-line?

If you want to have full control over how long labels are broken down across lines you can specify the breaking point by providing labels in a nested array. For example:
var chart = new Chart(ctx, {
...
data: {
labels: [["Label1 Line1:","Label1 Line2"],["Label2 Line1","Label2 Line2"]],
datasets: [{
...
});

You can use the following chart plugin :
plugins: [{
beforeInit: function(chart) {
chart.data.labels.forEach(function(e, i, a) {
if (/\n/.test(e)) {
a[i] = e.split(/\n/);
}
});
}
}]
add this followed by your chart options
ᴜꜱᴀɢᴇ :
add a new line character (\n) to your label, wherever you wish to add a line break.
ᴅᴇᴍᴏ
var chart = new Chart(ctx, {
type: 'horizontalBar',
data: {
labels: ['Jan\n2017', 'Feb', 'Mar', 'Apr'],
datasets: [{
label: 'BAR',
data: [1, 2, 3, 4],
backgroundColor: 'rgba(0, 119, 290, 0.7)'
}]
},
options: {
scales: {
xAxes: [{
ticks: {
beginAtZero: true
}
}]
}
},
plugins: [{
beforeInit: function(chart) {
chart.data.labels.forEach(function(e, i, a) {
if (/\n/.test(e)) {
a[i] = e.split(/\n/);
}
});
}
}]
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<canvas id="ctx"></canvas>

Related

Chart.js identification of min and max value before rendering

I am using chart.js for my project. As you can see in the following code, chart.js uses different minimum and maximum values for y-axis for line and bar graphs for same data. In the given code, 1100-1700 is the value range for line graph whereas 0-2000 is the value range used for bar graph.
I like to make same minimum and maximum values for both line and bar graphs. One option is to find minimum, maximum and step-size values my own and use the properties min, max and ticks.stepSize under scales. But finding minimum, maximum and step-size for a given data data is a serious task.
For my requirement, default minimum ,maximum and stepSize used by chart.js for line graph is fine and I would like to use the same values for bar graph also.
I could first render line graph, get these values from this graph (like scales.y.min) and then use it for bar graph, which is perfectly working
Is there a way I could get the default min, max, stepSize values used by chart.js for line graph before actually drawing the graph? Any answers or pointers are really appreciated. Thanks
var chart1 = new Chart(document.getElementById('chart1'),
{
type: 'line',
data:
{
labels: ['a','b','c'],
datasets:
[
{
label: 'A',
data: [1212,1122, 1188, 1617, 1116],
borderColor: 'green',
}
]
}
});
var chart2 = new Chart(document.getElementById('chart2'),
{
type: 'bar',
data:
{
labels: ['a','b','c'],
datasets:
[
{
label: 'A',
data: [1212,1122, 1188, 1617, 1116],
backgroundColor: 'green',
}
]
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.9.1/chart.min.js"></script>
<div style="width:300px;height:200px"><canvas id="chart1"></canvas></div>
<div style="width:300px;height:200px"><canvas id="chart2"></canvas></div>
The first thing you could do is to set beginAtZero to false to Y axis of bar chart because is set to true by default:
https://github.com/chartjs/Chart.js/blob/v3.9.1/src/controllers/controller.bar.js#L636-L650
Then you can set the same scale config to both charts.
options: { // options of charts
scales: {
y: {
beginAtZero: false,
}
}
}
var chart1 = new Chart(document.getElementById('myChart1'),
{
type: 'line',
data:
{
labels: ['a','b','c'],
datasets:
[
{
label: 'A',
data: [1212,1122, 1188, 1617, 1116],
borderColor: 'green',
}
]
},
options: {
scales: {
y: {
beginAtZero: false,
}
}
}
});
var chart2 = new Chart(document.getElementById('myChart2'),
{
type: 'bar',
data:
{
labels: ['a','b','c'],
datasets:
[
{
label: 'A',
data: [1212,1122, 1188, 1617, 1116],
backgroundColor: 'green',
}
]
},
options: {
scales: {
y: {
beginAtZero: false,
}
}
}
});
.myChartDiv {
max-width: 300px;
max-height: 200px;
}
<script src="https://cdn.jsdelivr.net/npm/chart.js#3.9.1/dist/chart.min.js"></script>
<html>
<body>
<div class="myChartDiv">
<canvas id="myChart1" width="300" height="200"/>
</div>
<div class="myChartDiv">
<canvas id="myChart2" width="300" height="200"/>
</div>
</body>
</html>

chart.js add clickable link to horizontal bar stacks

Hi there I am stuck in chat.js horizontal bar graph. Here is the JS script that is populating a horizontal bar chart perfectly. Now what I want is to add link on these horizontal bar stacks. Whenever I click a particular bar stack the user should be directed to that link.
var ctx = document.getElementById('qr_tagging_data');
ctx.height = 160;
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Total Tagged','Center Zone','North Zone','South Zone'],
datasets: [{
data: ['21500','5000','10000','6500'],
backgroundColor: [
'#53B63C', '#E8A412', '#128BE8', '#648fbb'
],
hoverOffset: 3
}]
},
plugins: [ChartDataLabels],
options: {
indexAxis: 'y',
responsive: true,
plugins: {
legend: {
display: false
},
datalabels: {
font: {
weight: 'bold',
size: '15'
}
}
}
},
});
function clickHandlerZones(evt) {
const points = myChart.getElementsAtEventForMode(evt, 'nearest', { intersect: true }, true);
if (points.length) {
alert(points.length);
const firstPoint = points[0];
const label = myChart.data.labels[firstPoint.index];
const value = myChart.data.datasets[firstPoint.datasetIndex].data[firstPoint.index];
window.open('google.com','_blank');
}
}
ctx.onclick = clickHandlerZones;
I have populated another chart.js graph but it is vertical bar graph and the bars are perfectly redirected whenever a user clicks on the vertical bar graph. I am pasting the code of vertical bar graph too for reference and suggestions.
var ctx = document.getElementById('hospital_data');
ctx.height = 300;
var myChart = new Chart(ctx, {
type: 'bar',
data: {
datasets: [{
data: <?php echo $hospitals_data?>,
backgroundColor: [<?php echo $legend_colors?>],
hoverOffset: 3
}]
},
plugins: [ChartDataLabels],
options: {
parsing:{
xAxisKey: 'hospital_name',
yAxisKey: 'tagging_count'
},
responsive: true,
plugins: {
legend: {
display: false
},
datalabels: {
formatter: function (value) {
return value['tagging_count'];
},
anchor: 'end',
align: 'top',
font: {
weight: 'bold',
size: '11'
}
}
}
}
});
function clickHandler(evt) {
const points = myChart.getElementsAtEventForMode(evt, 'nearest', { intersect: true }, true);
if (points.length) {
const firstPoint = points[0];
const label = myChart.data.labels[firstPoint.index];
const value = myChart.data.datasets[firstPoint.datasetIndex].data[firstPoint.index];
window.open('google.com','_blank');
}
}
ctx.onclick = clickHandler;
can someone guide how do I fix this horizontal bar stacks clickable functionality. The links are applied on the numbers i.e. (5000,10000,15000,20000,25000 on x-axis) rather they should be applied to each horizontal stack.

Chart.js Treemap Adding custom text to each rectangle

I am using chart.js to develop a TreeMap. It works great but the issue is each rectangle only shows the value of the data. I want to add some custom text next to the value. How do I achieve this?
var topTags = [
{tag:'python',num:133269},{tag:'javascript',num:109742},{tag:'java',num:65490},{tag:'c#',num:45445},{tag:'html',num:43767},{tag:'android',num:42657},{tag:'reactjs',num:38844},{tag:'php',num:34381},{tag:'sql',num:29996},{tag:'python',num:29942},{tag:'css',num:29654},{tag:'r',num:28319},{tag:'c++',num:27389},{tag:'node.js',num:25415},{tag:'angular',num:24093},{tag:'pandas',num:23826},{tag:'arrays',num:23075},{tag:'jquery',num:18968},{tag:'mysql',num:18863},{tag:'swift',num:17971},{tag:'ios',num:17600},{tag:'json',num:15589},{tag:'laravel',num:15537},{tag:'flutter',num:15201},{tag:'c',num:15195},{tag:'django',num:14748},{tag:'sql',num:12752},{tag:'reactjs',num:10974},{tag:'excel',num:10962},{tag:'list',num:10726},{tag:'regex',num:10676}
];
var canvas = document.getElementById("treemap");
var ctx = canvas.getContext("2d");
var chart = window.chart = new Chart(ctx, {
type: "treemap",
data: {
datasets: [{
tree: topTags,
key: "num",
groups: ['num'],
spacing: 0.5,
borderWidth: 1.5,
fontColor: "black",
borderColor: "grey"
}]
},
options: {
maintainAspectRatio: false,
legend: { display: false },
tooltips: { enabled: false }
}
});
When running this code, I get the numbers in each rectangle but I need some text to be appended next to the numbers for each rectangle. How do I achieve this?
You can use the formatter options in the labels section:
const options = {
type: 'treemap',
data: {
datasets: [{
label: '# of Votes',
tree: [12, 19, 3, 5, 2, 3],
backgroundColor: 'pink',
labels: {
display: true,
formatter(ctx) {
const data = ctx.chart.data;
return `Custom Text: ${data.datasets[ctx.datasetIndex].tree[ctx.dataIndex]}`;
}
},
}]
},
options: {}
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);
<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.7.0/chart.js"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-chart-treemap#2.0.1/dist/chartjs-chart-treemap.js"></script>
</body>

Chartjs tooltip anchor point position on bar charts

I have a bar chart using Chartjs, with a fixed y-axis max. Sometimes the data can exceed the max, but the hover tooltip is always anchored to the top of the bars so it cannot be seen. The tooltips' position option does not really work for me.
So, is there a way to display the tooltip at the bottom of the bars? Or can it follow the hovering mouse cursor like canvasjs?
var ctx = document.getElementById("chart").getContext("2d");
var barChart = new Chart(ctx, {
type: 'bar',
options: {
scales: {
yAxes: [{
display: true,
ticks: {
min: 0,
max: 120
},
}],
},
tooltips: {
// position: 'nearest',
position: 'average',
},
legend: {
display: false
}
},
data: {
labels: ["A", "B", "C", "D"],
datasets: [{
label: "Data Set 1",
backgroundColor: [
'#44b2d7',
'#44b2d7',
'#44b2d7',
'#44b2d7',
],
borderColor: [
'#44b2d7',
'#44b2d7',
'#44b2d7',
'#44b2d7'
],
borderWidth: 0,
data: [131, 65, 165, 85]
}]
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.5.0/Chart.min.js"></script>
<canvas id="chart" height="180"></canvas>
New modes can be defined by adding functions to the Chart.Tooltip.positioners map.
You can create your custom postitioning like in the Doc of chartjs:
Chart.Tooltip.positioners.custom = function(elements, eventPosition) {
/** #type {Chart.Tooltip} */
var tooltip = this;
/* ... */
return {
x: eventPosition.x,
y: eventPosition.y
};
}
you need to set your custom function into your options when rendering your chart:
tooltips: {
position : 'custom', //<-- important same name as your function above
callbacks: {
label: function(tooltipItem, data) {
var label = Math.floor(tooltipItem.yLabel*100)/100+" "+data.datasets[tooltipItem.datasetIndex].label;
return label;
}
}
}
Look my full Fiddle example.

Bar labels in Legend

My problem is similar to How to show bar labels in legend in Chart.js 2.1.6?
I want to have to same output a pie chart give, but I do not want to create multiple datasets. I managed to do this, but now I can't find how.
Here is my code sample :
var myChart = new Chart(ctx, {
type: type_p,
data: {
labels: ['Lundi','Mardi'],
datasets: [{
data: [50,20],
backgroundColor: color,
borderColor: color,
borderWidth: 1
}]
}
I want the same legend as a pie chart, but with a bar chart:
Is this a way to do this?
To accomplish this, you would have to generate custom labels (using generateLabels() function) based on the labels array of your dataset.
legend: {
labels: {
generateLabels: function(chart) {
var labels = chart.data.labels;
var dataset = chart.data.datasets[0];
var legend = labels.map(function(label, index) {
return {
datasetIndex: 0,
fillStyle: dataset.backgroundColor && dataset.backgroundColor[index],
strokeStyle: dataset.borderColor && dataset.borderColor[index],
lineWidth: dataset.borderWidth,
text: label
}
});
return legend;
}
}
}
add this in your chart options
ᴡᴏʀᴋɪɴɢ ᴇxᴀᴍᴘʟᴇ ⧩
var ctx = canvas.getContext('2d');
var chart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Lundi', 'Mardi', 'Mercredi', 'Jeudi', 'Vendredi'],
datasets: [{
data: [1, 2, 3, 4, 5],
backgroundColor: ['#ff6384', '#36a2eb', '#ffce56', '#4bc0c0', '#9966ff'],
borderColor: ['#ff6384', '#36a2eb', '#ffce56', '#4bc0c0', '#9966ff'],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
},
legend: {
labels: {
generateLabels: function(chart) {
var labels = chart.data.labels;
var dataset = chart.data.datasets[0];
var legend = labels.map(function(label, index) {
return {
datasetIndex: 0,
fillStyle: dataset.backgroundColor && dataset.backgroundColor[index],
strokeStyle: dataset.borderColor && dataset.borderColor[index],
lineWidth: dataset.borderWidth,
text: label
}
});
return legend;
}
}
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<canvas id="canvas"></canvas>

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