Displaying data from simple html form to display in chartjs - javascript

I am trying to create a simple form to collect input from the user then display the user data in a bar chart using chartjs. Below is my current javascript code. I want the testValue1, testValue2, testValue3 and testValue4 to display as my data. Any help on what I am missing would be greatly appreciated.
function displayGraph () {
let testOutput = document.getElementById("welcome");
let testValue1 = document.getElementById("test1");
let testValue2 = document.getElementById("test2");
let testValue3 = document.getElementById("test3");
let testValue4 = document.getElementById("test4");
}
let barChart = new Chart(rateOfReturn, {
type: 'bar',
data: {
labels: ["Rate of Return", "Fee #1", "Fee #2", "Fee #3"],
datasets: [{
label: 'Balance by Year',
data: [],
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
}]
},
});

I am not sure your implementation. If you trying to get a value from an input into a chart. Won't something like this work?
<canvas id="myChart" width="400" height="400"></canvas>
<script>
var ctx = document.getElementById("myChart").getContext('2d');
var testOutput = document.getElementById("welcome").value;
var testValue1 = document.getElementById("test1").value;
var testValue2 = document.getElementById("test2").value;
var testValue3 = document.getElementById("test3").value;
var testValue4 = document.getElementById("test4").value;
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [testValue1, testValue2, testValue3, testValue4],
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>
Reference: http://www.chartjs.org/docs/latest/

Maybe you can pass data instead of the empty array
datasets: [{
label: 'Balance by Year',
data: [], // Empty Array
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
}]
You can first follow the latest Bar chart example and then reproduce it for yourself. http://www.chartjs.org/docs/latest/charts/bar.html

Here you go. This works.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>SimpleAdd</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.3/Chart.min.js" charset="utf-8"></script>
</head>
<body>
<form>
Test:<br>
<input id="test1" type="text">
<input type="button" value="Add data" onclick="adddata()">
</form>
<canvas id="myChart"></canvas>
<script type="text/javascript">
var ctx = document.getElementById("myChart").getContext('2d');
function adddata() {
let test1 = document.getElementById("test1").value;
// myChart.data.labels[1] = testName1;
myChart.data.datasets[0].data[0] = test1;
myChart.update();
}
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Red"],
datasets: [{
label: '# of Votes',
data: [test1],
backgroundColor: [
'rgba(255, 99, 132, 0.2)'
],
borderColor: [
'rgba(255,99,132,1)'
],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
</script>
</body>
</html>

Related

No chart appears - Chart.js

I am not very experienced with JavaScript and have a bit of difficulty with chart.js I can't get the chart.js graph to appear. I've tried everything, but nothing; below I have left you a part of the code and the photo of how the "graph" looks. Thanks in advance
<h5 class="card-title">Line Chart</h5>
<div style="height: 400px">
<canvas id="line-char"></canvas>
<script>
const ctx = document.getElementById('myChart');
const ctx = document.getElementById('myChart').getContext('2d');
const ctx = $('#myChart');
const ctx = 'myChart';
</script>
<canvas id="line-char"></canvas>
<script>
const ctx = document.getElementById('line-char');
const line_char = 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>
Image link
Your chart configuration contains invalid characters in backgroundColor and borderColor (‘ instead of ').
‘rgba(75, 192, 192, 0.2)',
Please take a look at your amended and runnable code below and see how it works now.
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.7.0/chart.js"></script>
<h5 class="card-title">Line Chart</h5>
<div style="height: 400px">
<canvas id="line-char"></canvas>
<script>
new Chart('line-char', {
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>
</div>

Django - Chart.js doesn't return nothing

I'm new on js and i'm trying to build something simple. I've no error in the console but chart doesn't display on my Django website.
If someone can help me, please, would be great.
{% extends 'account/main.html' %}
<script>
{% block jquery %}
var endpoint = '/api/chart/data/'
var defaultData = []
var labels = [];
$.ajax({
method: "GET",
url: endpoint,
success: function(data){
labels = data.labels
defaultData = data.default
setChart()
},
error: function(error_data){
console.log("error")
console.log(error_data)
}
})
function setChart(){
var ctx = document.getElementById("myChart");
var ctx2 = document.getElementById("myChart2");
var myChart = new Chart(ctx2, {
type: 'bar',
data: {
labels: labels,
datasets: [{
label: '# of Votes',
data: defaultData,
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
}
}]
}
}
});
var myChart = new Chart(ctx, {
type: 'polarArea',
data: {
labels: labels,
datasets: [{
label: '# of Votes',
data: defaultData,
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
}
}]
}
}
});
}
// var ctx = document.getElementById("myChart");
{% endblock %}
</script>
{% block content %}
<head>
<title>Home</title>
</head>
<body>
<canvas id="myChart" width="400" height="400"></canvas>
<form method="GET" action="" name="myform" value="home" id="subform">
{% csrf_token %}
</form>

Chart.js Cannot read property 'fontSize' of undefined

Html
<div class="chart-container" style="height:315px">
<canvas id="test"></canvas>
</div>
I've included these files
<script src="/assets/vendors/jquery/dist/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.8.0/Chart.min.js" type="text/javascript"></script>
<script src="/assets/js/test.js"></script>
test.js
$(document).ready(function() {
var ctx = document.getElementById('test').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
}
}]
}
}
});
});
I used the sample code from https://www.chartjs.org/docs/latest/ for test.js. I'm also using laravel if that could have something to do with it.
Here's the error I'm getting.
Chart.min.js:7 Uncaught TypeError: Cannot read property 'fontSize' of
undefined
at Object._parseFont (Chart.min.js:7)
at i.fit (Chart.min.js:7)
at i.update (Chart.min.js:7)
at Chart.min.js:7
at Object.each (Chart.min.js:7)
at Object.update (Chart.min.js:7)
at ni.updateLayout (Chart.min.js:7)
at ni.update (Chart.min.js:7)
at ni.construct (Chart.min.js:7)
at new ni (Chart.min.js:7)
EDIT
Removing $(document).ready() fixed the problem
Please check this example jquery 2.2.4
// find elements
var ctx = document.getElementById('myChart');
var ctx = document.getElementById('myChart').getContext('2d');
var ctx = $('#myChart');
var ctx = 'myChart';
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
}
}]
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<canvas id="myChart" width="400" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.8.0/Chart.min.js" type="text/javascript"></script>
It works perfectly fine if you properly source the jQuery library.
Check here https://jsfiddle.net/g7qmh8wL/1/
// no code changes required.

HTML 5 chartjs not working as static file

I am trying to use the chartjs to draw charts using HTML5. Does it not work if I open the HTML file by right-clicking on it and open in google chrome. I am seeing a blank screen for the following code:
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.js"/>
<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>
<body>
<div style="width:75%;">
<canvas id="myChart" width="400" height="400"></canvas>
</div>
</body>
</html>
Am I doing something wrong in code or do I need a server(eg. apache) to run the page?
There were basically two problems:
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.js" /> is not a valid script. It should be <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.js"></script>
Your second script must be loaded once HTML/DOM is rendered. getContext () was not able to find canvas id.
Below is working example:
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.js"></script>
<body>
<div style="width:75%;">
<canvas id="myChart" width="400" height="400"></canvas>
</div>
</body>
<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>
</html>

Chartjs – change tooltip border radius

I have created a simple horizontal bar chart using chartjs.
var ctx = $('#myChart');
var myChart = new Chart(ctx, {
type: 'horizontalBar',
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
}]
},
});
Now my requirement is to change the border radius of tooltip to make it rectangle. I have tried changing the border radius property but It doesn’t seem to work. Does anyone know how can I change radius of tooltip?
Thanks in advance.
This can be achieved by setting cornerRadius property to 0 (or any number) for tooltips in your chart options.
options: {
tooltips: {
cornerRadius: 0
},
...
}
working example
var ctx = $('#myChart');
var myChart = new Chart(ctx, {
type: 'horizontalBar',
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: {
tooltips: {
cornerRadius: 0 //<- set this
},
scales: {
xAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<canvas id="myChart"></canvas>

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