I am working on a project and we are using a chart created with chart js. I want to give the legend a background color (the top part thats drawn in the image). After a lot of searching on the internet i stil havent found a solution to my problem so i thought lets try stack overflow. can some one help me Please??>!
the part i want to give a background color
here is part of my code
enter code here
<div>
<canvas id="myChart"></canvas>
</div>
<script>
const labels = [
'January',
'February',
'March',
'April',
'May',
'June',
];
const data = {
labels: labels,
datasets: [{
label: 'My First dataset',
backgroundColor: 'rgb(255, 99, 132)',
borderColor: 'rgb(255, 99, 132)',
data: [0, 10, 5, 2, 20, 30, 45],
}]
};
const config = {
type: 'line',
data: data,
options: {}
};
var myChart = new Chart(
document.getElementById('myChart'),
config
);
</script>
You can use a custom plugin for this:
const plugin = {
id: 'legendBackground',
beforeDraw: (chart, args, opts) => {
const {
chartArea: {
width,
top,
left
},
ctx
} = chart;
ctx.fillStyle = opts.color || 'transparent';
ctx.fillRect(left, 0, width, top)
}
}
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'
}]
},
options: {
plugins: {
legendBackground: {
color: 'pink'
}
}
},
plugins: [plugin]
}
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/3.7.1/chart.js"></script>
</body>
I need the Holiday tooltip to be grouped, that is to say, pressing a tooltip stops seeing all the Holidays. In this way, not having the "Holiday" tooltip repeated twice and showing / hiding with a single tooltip
Is it possible with chart js?
Actual:
Expected:
a single tooltip handling the "Holiday" datasets
Actual code:
var options = {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple"],
datasets: [
{
label: 'HOLIDAY',
data: [10, 10,10,10,10],
borderWidth: 1,
backgroundColor: "red",
stack: 1
},
{
label: 'HOLIDAY',
data: [10, 10,10,10,10],
borderWidth: 1,
backgroundColor: "red",
stack: 2
},
{
label: 'IN OFFICE',
data: [7, 11, 5, 8, 3],
borderWidth: 1,
backgroundColor: "blue",
stack:1
},
{
label: 'HOME OFFICE',
data: [7, 11, 5, 8, 3],
borderWidth: 1,
backgroundColor: "yellow",
stack:2
}
]
},
options: {
indexAxis: 'y',
// Elements options apply to all of the options unless overridden in a dataset
// In this case, we are setting the border of each horizontal bar to be 2px wide
elements: {
bar: {
borderWidth: 2,
}
},
}
}
var ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);
<body>
<canvas id="chartJSContainer" width="400" height="100"></canvas>
<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
</body>
Space between column in chart js
There's the screen of my output and what i want to do
enter image description here
Anyone can help please ?
You can achieve this by setting the barPercentage property
Example:
var options = {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderWidth: 1,
backgroundColor: 'blue',
barPercentage: 0.3
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
borderWidth: 1,
backgroundColor: 'red',
barPercentage: 0.3
}
]
},
options: {
scales: {
y: {
stacked: true
},
x: {
stacked: true
}
}
}
}
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>
Now i have something like this but i need to add space between each column
Show only the data points that have a change.
In order to reduce the clutter, I want to not show the circles when the prev value or next are the same. Still when you hover over them to show the label with information.
This is how I want it to look:
The second and third circles are the same, they must be hidden and only show on hover:
you can use the following options to style the points...
pointBackgroundColor, pointBorderColor, pointBorderWidth
but instead of providing a single value...
pointBackgroundColor: '#ffffff',
pointBorderColor: 'rgb(102, 187, 106)',
pointBorderWidth: 2,
you'll need to provide an array, with values for each point in the dataset,
then you can change the value for the points in question.
for the points you do not want to show, use color such as 'transparent'.
this will hide the point, but still show tooltip on hover.
pointBackgroundColor: ['#ffffff', '#ffffff', 'transparent', 'transparent', '#ffffff', '#ffffff'],
pointBorderColor: ['rgb(102, 187, 106)', 'rgb(102, 187, 106)', 'transparent', 'transparent', 'rgb(102, 187, 106)', 'rgb(102, 187, 106)'],
pointBorderWidth: [2, 2, 0, 0, 2, 2]
see following working snippet...
new Chart(document.getElementById('myChart').getContext('2d'), {
type: 'line',
data: {
labels: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
datasets: [{
backgroundColor: 'rgba(102, 187, 106, 0.2)',
borderColor: 'rgb(102, 187, 106)',
borderWidth: 2,
data: [5, 6, 6, 6, 6, 7, 6, 6, 5, 4],
label: 'y',
lineTension: 0,
pointBackgroundColor: ['#ffffff', '#ffffff', 'transparent', 'transparent', '#ffffff', '#ffffff', '#ffffff', '#ffffff', '#ffffff', '#ffffff'],
pointBorderColor: ['rgb(102, 187, 106)', 'rgb(102, 187, 106)', 'transparent', 'transparent', 'rgb(102, 187, 106)', 'rgb(102, 187, 106)', 'rgb(102, 187, 106)', 'rgb(102, 187, 106)', 'rgb(102, 187, 106)', 'rgb(102, 187, 106)'],
pointBorderWidth: [2, 2, 0, 0, 2, 2, 2, 2, 2, 2]
}]
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.bundle.min.js"></script>
<canvas id="myChart"></canvas>
A slightly different approach to WhiteHat's (ninja'd!) that iterates the series via .forEach to build the colour options:
Edit: Minor tweak to if to account for previous and next value in deciding point visibility and added hover colour settings to show hidden point on hover.
let labels = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'],
series = [10, 5, 5, 5, 5, 2, 3, 3, 3, 10],
pointBackgroundColor = [],
pointBorderColor = [],
pointHoverBackgroundColor = 'white',
pointHoverBorderColor = 'red';
series.forEach(
(value, index) => {
if (value == series[index - 1] && value == series[index + 1]) {
pointBackgroundColor.push('transparent');
pointBorderColor.push('transparent');
} else {
pointBackgroundColor.push('white');
pointBorderColor.push('red');
}
});
myChart = new Chart(document.getElementById('chart'), {
type: 'line',
data: {
labels: labels,
datasets: [{
label: 'series1',
data: series,
pointBackgroundColor: pointBackgroundColor,
pointBorderColor: pointBorderColor,
pointHoverBackgroundColor: pointHoverBackgroundColor,
pointHoverBorderColor: pointHoverBorderColor
}]
},
options: {
maintainAspectRatio: false,
tooltips: {
mode: 'index',
intersect: false
},
hover: {
intersect: false
}
}
});
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.min.js"></script>
<canvas id="chart"></canvas>
WhiteHat solution is good but doesn't achieve the desired effect. When you hover over a hidden data point circle it should make the circle visible.
Here is how I did it
Step 1:
In the backend using PHP, I check if the prev and next point are different, and made a point radius 0.
$countPoints = count($points);
for ($i=1; $i < $countPoints-1; $i++) {
$prevVal = $chartChange[$i-1];
$nextVal = $chartChange[$i+1];
if($chartChange[$i] == $prevVal && $chartChange[$i] == $nextVal){
$points[$i] = 0;
}
}
Step 2 :
Add and pass the imploded array to the options object. Using [3,0,3,3] format
pointRadius: [{/literal}{$points}{literal}]
Edit:
Using only js
let labels = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'],
series = [10, 5, 5, 5, 5, 2, 3, 3, 3, 10],
pointRadius = [],
pointBackgroundColor = "rgb(230, 247, 238)",
pointBorderColor = "rgb(47, 186, 117)";
series.forEach(
(value, index) => {
if (value == series[index - 1] && value == series[index + 1]) {
pointRadius.push(0);
} else {
pointRadius.push(4);
}
});
myChart = new Chart(document.getElementById('myChart'), {
type: 'line',
data: {
labels: labels,
datasets: [{
label: 'series1',
fill: 'start',
pointRadius: pointRadius,
data: series,
backgroundColor:pointBackgroundColor,
borderColor:pointBorderColor,
pointHoverRadius: 4,
pointBackgroundColor: pointBackgroundColor,
pointBorderColor: pointBorderColor,
}]
},
options: {
tooltips: {
// mode: 'index',
intersect: false
},
tooltips: {
mode: 'index',
axis: 'x',
intersect: false
},
hover: {
intersect: false
},
maintainAspectRatio: false
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.bundle.min.js"></script>
<canvas id="myChart"></canvas>
I have a bar chart with a title on top. How can I go about changing the legend’s position to right of the chart. I searched on other forums but couldn’t find anything. Here is my code:
let ctx = document.getElementById('canvas');
let chart = new Chart(ctx, {
type: 'bar',
data: {
labels: [1, 2, 3, 4, 5],
datasets: [{
label: 'Votes',
data: [1, 2, 3, 4, 5],
backgroundColor: 'rgba(255, 0, 0, 0.2)'
}, {
label: 'Score',
data: [1, 2, 3, 4, 5],
backgroundColor: 'rgba(0, 255, 0, 0.2)'
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
You could set legend's position property to right in your chart options, to place the legend at the right side of the chart ...
options: {
legend: {
position: 'right'
},
...
}
ᴅᴇᴍᴏ
let ctx = document.getElementById('canvas').getContext('2d');
let chart = new Chart(ctx, {
type: 'bar',
data: {
labels: [1, 2, 3, 4, 5],
datasets: [{
label: 'Votes',
data: [1, 2, 3, 4, 5],
backgroundColor: 'rgba(255, 0, 0, 0.2)'
}, {
label: 'Score',
data: [1, 2, 3, 4, 5],
backgroundColor: 'rgba(0, 255, 0, 0.2)'
}]
},
options: {
legend: {
position: 'right'
},
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.5.0/Chart.min.js"></script>
<canvas id="canvas"></canvas>