I'm using line chart js to display a graph and I'm trying to calculate the difference between the selected point and the previous one and render it in a tool tip.
I've read that I should use callbacks function but when I tried it nothing happen.
Even I only try to change the tittle
Here's my options for my line chart if anyone can help :)
Chart js version : 3.6.1
plugins: {
legend: {
display: false
},
title: {
display: true,
font: {
size: 18,
},
color: "white"
},
zoom: {
zoom: {
drag: {
enabled: true
},
mode: 'xy',
}
},
tooltip: {
callbacks: {
title: function () {
return "my tittle";
}
}
}
}
This is because you are using V2 syntax in with V3, you can read the namespace in the options.
Tooltip has been moved to the plugins section
For all changes please read the migration guide
const options = {
type: 'line',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderColor: 'orange'
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
borderColor: 'pink'
}
]
},
options: {
plugins: {
tooltip: {
callbacks: {
title: () => ('Title')
}
}
}
}
}
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/3.6.2/chart.js"></script>
</body>
Related
wishing you all a happy week
I was wondering if you could help me, I'm using Chartjs from the server side to apply charts in reports and call them from the frontend.
The technologies that I am using is nodejs node developed with typescript and express and I am using handlebars for HTML templates, integrate Chartjs, since in addition to being free it is highly recommended in the community, but right now I am having some problems with the implementation
To better integrate the charts from the server I am using chartjs-node-canvas
and generating images through the library,once I have the image I pass it to my template
So what I want to add sub tags to group the information, adding multilevel category tags, but it throws me the following error when I want to use the hooks in the plugins
image1 of the error
How to properly access Chartjs plugin hooks?
In the end, I would like to achieve something like this:
example of the expected result
I leave the code of the configuration of my graph, any type of help would be very grateful, I am new to the community, I hope I have written the question correctly. Thank you very much to all
import {
ChartJSNodeCanvas
} from "chartjs-node-canvas";
const canvasRenderService = new ChartJSNodeCanvas({
width: 1100,
height: 700,
chartCallback: (ChartJS) => {
ChartJS.register(require('chartjs-plugin-datalabels'))
}
});
const mkChart = await canvasRenderService.renderToBuffer({
type: 'bar',
data: {
labels: labels,
datasets: [{
type: 'line',
label: '% ACTIVITY',
backgroundColor: '#FF7605',
borderColor: '#FF7605',
data: lineBar,
datalabels: {
anchor: 'start',
align: 'center',
clamp: true,
backgroundColor: '#FF7605',
color: 'white',
font: {
weight: 'bold'
}
}
},
{
type: 'bar',
label: 'WEEKLY SUMMARY OF HOURS',
backgroundColor: '#222A35',
borderColor: '#222A35',
data: barHorizontal,
datalabels: {
rotation: 270,
padding: 10
}
},
{
type: 'bar',
label: 'HOURS',
backgroundColor: '#008582',
borderColor: '#008582',
data: colbWeekly,
datalabels: {
anchor: 'end',
align: 'top',
clamp: true,
backgroundColor: '#008582',
color: 'white',
font: {
weight: 'bold'
}
}
}
]
},
options: {
plugins: {
datalabels: {
color: 'white',
font: {
weight: 'bold'
},
},
title: {
display: true,
text: 'AVERAGE WEEKLY HOURS'
},
afterDatasetsDraw(chart, args, pluginOptions) {
const {
ctx,
chartArea: {
left,
right,
top,
bottom,
width,
height
}
} = chart;
ctx.save();
ctx.font = 'bolder 12px sans-serif';
ctx.fillStyle = 'rgba(102, 102, 102, 1)';
ctx.textAlign = 'center';
ctx.fillText('WEEK 1', width / 4 + left, bottom + 30)
}
},
elements: {
line: {
fill: false
}
},
scales: {
xAxis: {
stacked: true,
ticks: {
minRotation: 90
},
grid: {
display: false
}
}
}
}
});
You can't access the plugin hooks from a specific plugin within the config of that plugin, you will need to create your own custom plugin and in the plugin itself you can access all the hooks:
const customPlugin = {
id: 'customPlugin',
afterDatasetsDraw: (chart, args, opts) => {
console.log('afterDatasetsDraw')
},
beforeDatasetsDraw: (chart, args, opts) => {
console.log('beforeDatasetsDraw');
}
// You can add all the other hooks here
}
const options = {
type: 'line',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderColor: 'pink'
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
borderColor: 'orange'
}
]
},
options: {},
plugins: [customPlugin]
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.9.1/chart.js"></script>
<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
</body>
I want to add datalabels to the top of each bar and color them in black and make it in bigger font. Like this:
my chart with necessary labels
But all that I tried don't change the chart.
I add chartjs and charts-plugin-datalabels:
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.8.0/chart.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/chartjs-plugin-datalabels/2.0.0/chartjs-plugin-datalabels.js"></script>
Chart creating function:
function bars_chart(data, period) {
Chart.register(ChartDataLabels)
document.querySelector('#chartContainer').innerHTML = '<canvas id="bar-chart-horizontal"></canvas>'
var chartConfig = {
type: 'bar',
data: {
labels: period,
datasets: data
},
options: {
responsive: true,
plugins: {
dataLabels: {
font: {
color: "#000000",
size: 25
},
color: "#000000"
},
legend: {
position: 'top',
},
title: {
display: true,
text: 'Chart.js Bar Chart'
},
}
},
};
new Chart(document.getElementById("bar-chart-horizontal"), chartConfig);
}
It looks like there is a simple solution but I can't find it)
Your namespace is wrong, you putted a capital L in there while it needs to be fully lower case. After that you can set anchor and align to 'end' to get the value on top of the bars:
Chart.register(ChartDataLabels)
const options = {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: 'pink'
}]
},
options: {
plugins: {
datalabels: {
color: 'black',
font: {
size: 40
},
anchor: 'end',
align: 'end'
}
}
}
}
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/3.8.0/chart.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/chartjs-plugin-datalabels/2.0.0/chartjs-plugin-datalabels.js"></script>
</body>
I've got the following function making doughnut charts in ChartJS, the function imports the data, label text, and the id of the element. For some reason the options legend labels does not work for me. The default color of '#666' is not usable for my site's layout either.
my function:
function newDoughnutChart(id, labels, data) {
var donutChartCanvas = $(id).get(0).getContext('2d')
var donutData = {
labels: labels,
datasets: [
{
data: data,
backgroundColor: backgroundColor,
}
]
}
var donutOptions = {
maintainAspectRatio: false,
responsive: true,
options: {
legend: {
labels: {
usePointStyle: true,
fontColor: "#fff",
}
}
}
}
new Chart(donutChartCanvas, {
type: 'doughnut',
data: donutData,
options: donutOptions
})
}
backgroundColor is a variable I've set globally for this js file.
The legend config has been moved to the plugins section
Example:
var options = {
type: 'line',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderWidth: 1
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
borderWidth: 1
}
]
},
options: {
plugins: {
legend: {
labels: {
color: 'red'
}
}
}
}
}
var 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/3.3.2/chart.js"></script>
</body>
var donutOptions = {
maintainAspectRatio: false,
responsive: true,
options: {
plugins: {
legend: {
display: true,
labels: {
color: 'rgb(255, 99, 132)'
}
}
}
}
}
You can change the color by grabbing the class of that div tag using CSS selector. But It's not the best idea because it will change the color in your whole app.
I am having trouble with my chartsjs labels.
my graph generates fine, I am trying to set the chart so that the data labels are for the text part of the data and not the numbers part. my code shows the data labels as 4, 6 and 2 where as i need them to show the text: me, you and them.
<script>
var ctx = document.getElementById('myChart4').getContext('2d');
var myChart4 = new Chart(ctx, {
plugins: [ChartDataLabels],
type: 'doughnut',
data: {
labels: ['me','you','them'
],
datasets: [{
label: false,
data: [4,6,2
],
}]
},
options: {
responsive: false,
plugins: {
datalabels: {
color: 'black',
anchor: 'end',
align: 'end',
offset: 15
},
legend: {
display: false
},
title: {
display: true,
text:'Reason'
}
},
responsive: false,
onClick: (evt, activeEls) => {
show();
},
}
});
You can use the formatter function for this:
Chart.register(ChartDataLabels)
const options = {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: 'orange'
}]
},
options: {
plugins: {
datalabels: {
color: 'black',
anchor: 'end',
align: 'end',
offset: 15,
formatter: (val, ctx) => (ctx.chart.data.labels[ctx.dataIndex])
},
}
}
}
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/3.6.0/chart.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/chartjs-plugin-datalabels/2.0.0/chartjs-plugin-datalabels.js"></script>
</body>
I've got the following function making doughnut charts in ChartJS, the function imports the data, label text, and the id of the element. For some reason the options legend labels does not work for me. The default color of '#666' is not usable for my site's layout either.
my function:
function newDoughnutChart(id, labels, data) {
var donutChartCanvas = $(id).get(0).getContext('2d')
var donutData = {
labels: labels,
datasets: [
{
data: data,
backgroundColor: backgroundColor,
}
]
}
var donutOptions = {
maintainAspectRatio: false,
responsive: true,
options: {
legend: {
labels: {
usePointStyle: true,
fontColor: "#fff",
}
}
}
}
new Chart(donutChartCanvas, {
type: 'doughnut',
data: donutData,
options: donutOptions
})
}
backgroundColor is a variable I've set globally for this js file.
The legend config has been moved to the plugins section
Example:
var options = {
type: 'line',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderWidth: 1
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
borderWidth: 1
}
]
},
options: {
plugins: {
legend: {
labels: {
color: 'red'
}
}
}
}
}
var 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/3.3.2/chart.js"></script>
</body>
var donutOptions = {
maintainAspectRatio: false,
responsive: true,
options: {
plugins: {
legend: {
display: true,
labels: {
color: 'rgb(255, 99, 132)'
}
}
}
}
}
You can change the color by grabbing the class of that div tag using CSS selector. But It's not the best idea because it will change the color in your whole app.