How to read and plot json with Chart.js - javascript

I have an html file like this:
<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.1.6/Chart.min.js"></script>
<script src="https://code.jquery.com/jquery-3.1.0.min.js"></script>
</head>
<body>
<canvas id="myChart" width="400" height="400"></canvas>
<script>
function drawChart() {
console.log("start");
$.getJSON("test.json", function (data) {
console.log("loaded");
var ctx = document.getElementById("myChart");
var myChart = new Chart(ctx, {
type: 'bar',
data: data,
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero:true
}
}]
}
}
});
}).fail(function(){
console.log("fail")
});
}
drawChart()
</script>
</body>
</html>
... and a json file like this:
{
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [20, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
}
... and the json load always fails.
I tried several methods to read json and draw chart with Chart.js, but always failed.
I tried to plot the json with php without success:
<?php
header("Content-Type: application/json");
$filename = "test.json";
$fp = fopen($filename, "r");
$content = fread($fp, filesize($filename));
explode("\n", $content);
fclose($fp);
print_r($content);
?>
What's wrong with this?

The problem is with the JSON file. You should use quotation marks (").
Here is the correct JSON file:
{
"labels": ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
"datasets": [{
"label": "# of Votes",
"data": [20, 19, 3, 5, 2, 3],
"backgroundColor": [
"rgba(255, 99, 132, 0.2)",
"rgba(54, 162, 235, 0.2)",
"rgba(255, 206, 86, 0.2)",
"rgba(75, 192, 192, 0.2)",
"rgba(153, 102, 255, 0.2)",
"rgba(255, 159, 64, 0.2)"
],
"borderColor": [
"rgba(255,99,132,1)",
"rgba(54, 162, 235, 1)",
"rgba(255, 206, 86, 1)",
"rgba(75, 192, 192, 1)",
"rgba(153, 102, 255, 1)",
"rgba(255, 159, 64, 1)"
],
"borderWidth": 1
}]
}

Please change your PHP to:
<?php
header("Content-Type: application/json");
echo file_get_contents("test.json");

Related

How i can use chart.js script in function.php as a short code, Please fixed the issue in my code

I want to create a shortcode for chart.js, when I add this code without function in a page then it works fine, however, When I add this code in fuction.php it breaks the site. I already have tried my methods.
function chartJS_shortcode(){
?><canvas id="myChart" width="400" height="400"></canvas><?php
<script>
const ctx = document.getElementById('myChart').getContext('2d');
const myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255, 99, 132, 1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
y: {
beginAtZero: true
}
}
}
});
</script>
}
add_shortcode("chartJS", "chartJS_shortcode");
Always use return with shortcodes, try following it will work
<?php function chartJS_shortcode(){
ob_start();
?><canvas id="myChart" width="400" height="400"></canvas>
<script>
const ctx = document.getElementById('myChart').getContext('2d');
const myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255, 99, 132, 1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
y: {
beginAtZero: true
}
}
}
});
</script>
<?php
return ob_get_clean();
}
add_shortcode("chartJS", "chartJS_shortcode"); ?>

how do I make chart.js smaller? (html, chart.js)

I am trying to make my chart smaller but couldn't figure out how.
<canvas id="myChart"
style="position: relative" width="200" height="100">
</canvas>
My chart.js html code.
<script>
var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero:true
}
}]
}
}
});
</script>
and the js script.
So the width and height in my canvas is set to 200 and 100 (been trying out different values but not success).
I want it to be smaller so i can put it next to my div but it just gets way to big.
thanks in advance.
Wrap it in a <div>, i.e:
<div style="width:100px; height:100px">
<canvas id="myChart"></canvas>
</div>
Example below:
var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero:true
}
}]
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.3/Chart.min.js"></script>
<div style="width:300px; height:300px">
<canvas id="myChart"></canvas>
</div>

Chart Js reduce text size for label on X axis

I'm using Chart.js (http://www.chartjs.org/) and it's working fine, but I have too big X labels also with 45 degrees orientation (is auto adjusting).
I would like to reduce the size of that text, is it possible to do only for X axis?
thanks
Yes in the ticks.fontSize configuration you can do it only for the x-axis. For example
var ctx = document.getElementById("myChart");
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}],
xAxes: [{
ticks: {
fontSize: 8
}
}]
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.bundle.min.js"></script>
<canvas id="myChart" width="400" height="400"></canvas>

How to shorten Chart.js label

The problem I'm facing is I have 2 charts, made with Chart.js, them contains dynamics labels descriptions, if some label descriptions is too long, chart is turning smaller, but I need that both charts contain same height.
How can I configure Chart.js to shorten labels, and shows complete label like HTML title when mouse hover, to maintain the label area height?
What I need is maintain height of chart area, no matter how long the label is.
var options = {
//maintainAspectRatio: false,
responsive:true,
scales: {
yAxes: [{
ticks: {
beginAtZero:true
}
}]
}
};
var ctx = document.getElementById("myCanvas1");
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red", "Blue yjfid ", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: options
});
var ctx = document.getElementById("myCanvas2");
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: options
});
div{
display: inline-block;
width: 49%;
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>JS Bin</title>
</head>
<body>
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.js"></script>
<div>
<canvas id="myCanvas1" ></canvas>
</div>
<div>
<canvas id="myCanvas2"></canvas>
</div>
</body>
</html>
This answer reference from post.On mouse hover you can see tooltip showing full label name
var options = {
scales: {
xAxes: [{
ticks: {
callback: function(value) {
if (value.length > 4) {
return value.substr(0, 4) + '...'; //truncate
} else {
return value
}
},
}
}],
yAxes: [{}]
},
tooltips: {
enabled: true,
mode: 'label',
callbacks: {
title: function(tooltipItems, data) {
var idx = tooltipItems[0].index;
return 'Title:' + data.labels[idx]; //do something with title
},
label: function(tooltipItems, data) {
//var idx = tooltipItems.index;
//return data.labels[idx] + ' €';
return tooltipItems.xLabel + ' €';
}
}
},
};
var ctx = document.getElementById("myCanvas1");
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red", "Blue mbkjbjkbjlkbk", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: options
});
var ctx = document.getElementById("myCanvas2");
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: options
});
div {
display: inline-block;
width: 49%;
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>JS Bin</title>
</head>
<body>
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.js"></script>
<div>
<canvas id="myCanvas1"></canvas>
</div>
<div>
<canvas id="myCanvas2"></canvas>
</div>
</body>
</html>

ChartJS 'Hello World' not animating

I've been trying to get the ChartJS example from http://www.chartjs.org/docs/latest/ working, but I'm running into two unexpected issues:
The graph is not animating
The graph is huge (it seems to be ignoring the height/width properties on the canvas element).
Snippet (copied from the documentation) is here: https://codepen.io/anon/pen/KmOQoj
<html>
<head>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.js">
</script>
<script>
function load() {
var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero:true
}
}]
}
}
});
}
</script>
</head>
<body onload="load()">
<canvas id="myChart" width="400" height="400"></canvas>
</body>
</html>
here is working code
keep canvas inside div and set height and width for div and make chart as responsive
function load() {
var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
type: 'bar',
responsive:true,
maintainAspectRatio: false,
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero:false
}
}]
}
}
});
}
<html>
<head>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.js"></script>
</head>
<body onload="load()">
<div style="width:400px;height:400px">
<canvas id="myChart" width="400" height="400"></canvas>
</div>
</body>
</html>

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