I created an basic bar chart using chartjs and it works fine. Now I want to update the values on a time based interval. My problem is that after I created the chart, I do not know how to update its values correctly...
My code:
var ctx = $("#myChart").get(0).getContext("2d");
var dts = [
{
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,1)",
data: [0, 0, 0, 0, 0]
}
];
var data = {
labels: ["Core#1", "Core#2", "Core#3", "Core#4", "Total"],
datasets: dts
};
var chart = new Chart(ctx);
chart.Bar(data);
//test code
setInterval( function () {
data.datasets[0].data = [random(), random(), random(), random(), random()];
chart.Bar(data);
},2000);
in the test code, I am updating the values with datasets[0].data- is this the right way to do it? The problem with this is that everytime I call chart.Bar(), the values are reset to 0 then animated to the random value (like I am recreating the chart). This way, all animations are always from 0 to value which looks strange. I would expect that if I update a value from 50 to 10 the bar would go down to 10 from 50 and not setted to 0 then animated to 10.
I did not found anything in the docs about this... am I doing something wrong or this is impossible with this library?
Update: Looks like chartjs has been updated (see comment below). There are some examples up that look very nice:
Here's an example of updating a line chart using new data: http://jsbin.com/yitep/5/edit
Here's how we can update existing data on a line chart: http://jsbin.com/yitep/4/edit
Original Post
As of Nov 2013, there seem to be very few options for updating charts.
There is a good example here (duplicated below) of adding new points to a line chart. Still kind of jumpy but not too bad. However, I think the effect probably depends on the chart you are using.
It does look like this is somewhere in the development pipeline. I don't see any indication of a release date yet though: https://github.com/nnnick/Chart.js/issues/13 [Closed as of Jul 26, 2014]
JS
$(document).ready(function(){
var count = 10;
var data = {
labels : ["1","2","3","4","5", "6", "7", "8", "9", "10"],
datasets : [
{
fillColor : "rgba(220,220,220,0.5)",
strokeColor : "rgba(220,220,220,1)",
pointColor : "rgba(220,220,220,1)",
pointStrokeColor : "#fff",
data : [65,59,90,81,56,45,30,20,3,37]
},
{
fillColor : "rgba(151,187,205,0.5)",
strokeColor : "rgba(151,187,205,1)",
pointColor : "rgba(151,187,205,1)",
pointStrokeColor : "#fff",
data : [28,48,40,19,96,87,66,97,92,85]
}
]
}
// this is ugly, don't judge me
var updateData = function(oldData){
var labels = oldData["labels"];
var dataSetA = oldData["datasets"][0]["data"];
var dataSetB = oldData["datasets"][1]["data"];
labels.shift();
count++;
labels.push(count.toString());
var newDataA = dataSetA[9] + (20 - Math.floor(Math.random() * (41)));
var newDataB = dataSetB[9] + (20 - Math.floor(Math.random() * (41)));
dataSetA.push(newDataA);
dataSetB.push(newDataB);
dataSetA.shift();
dataSetB.shift(); };
var optionsAnimation = {
//Boolean - If we want to override with a hard coded scale
scaleOverride : true,
//** Required if scaleOverride is true **
//Number - The number of steps in a hard coded scale
scaleSteps : 10,
//Number - The value jump in the hard coded scale
scaleStepWidth : 10,
//Number - The scale starting value
scaleStartValue : 0
}
// Not sure why the scaleOverride isn't working...
var optionsNoAnimation = {
animation : false,
//Boolean - If we want to override with a hard coded scale
scaleOverride : true,
//** Required if scaleOverride is true **
//Number - The number of steps in a hard coded scale
scaleSteps : 20,
//Number - The value jump in the hard coded scale
scaleStepWidth : 10,
//Number - The scale starting value
scaleStartValue : 0
}
//Get the context of the canvas element we want to select
var ctx = document.getElementById("myChart").getContext("2d");
var optionsNoAnimation = {animation : false}
var myNewChart = new Chart(ctx);
myNewChart.Line(data, optionsAnimation);
setInterval(function(){
updateData(data);
myNewChart.Line(data, optionsNoAnimation)
;}, 2000
);
});
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0;l<a.datasets[f].data.length;l++)a.datasets[f].data[l]>e&&(e=a.datasets[f].data[l]),a.datasets[f].data[l]<h&&(h=a.datasets[f].data[l]);f=Math.floor(g/(0.66*d));d=Math.floor(0.5*(g/d));l=c.scaleShowLabels?c.scaleLabel:"";c.scaleOverride?(j={steps:c.scaleSteps,stepValue:c.scaleStepWidth,graphMin:c.scaleStartValue,labels:[]},z(l,j.labels,j.steps,c.scaleStartValue,c.scaleStepWidth)):j=C(g,f,d,e,h,l);k=Math.floor(g/j.steps);d=1;if(c.scaleShowLabels){b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily;
for(e=0;e<j.labels.length;e++)h=b.measureText(j.labels[e]).width,d=h>d?h:d;d+=10}r=q-d-t;m=Math.floor(r/(a.labels.length-1));n=q-t/2-r;p=g+c.scaleFontSize/2;x(c,function(){b.lineWidth=c.scaleLineWidth;b.strokeStyle=c.scaleLineColor;b.beginPath();b.moveTo(q-t/2+5,p);b.lineTo(q-t/2-r-5,p);b.stroke();0<s?(b.save(),b.textAlign="right"):b.textAlign="center";b.fillStyle=c.scaleFontColor;for(var d=0;d<a.labels.length;d++)b.save(),0<s?(b.translate(n+d*m,p+c.scaleFontSize),b.rotate(-(s*(Math.PI/180))),b.fillText(a.labels[d],
0,0),b.restore()):b.fillText(a.labels[d],n+d*m,p+c.scaleFontSize+3),b.beginPath(),b.moveTo(n+d*m,p+3),c.scaleShowGridLines&&0<d?(b.lineWidth=c.scaleGridLineWidth,b.strokeStyle=c.scaleGridLineColor,b.lineTo(n+d*m,5)):b.lineTo(n+d*m,p+3),b.stroke();b.lineWidth=c.scaleLineWidth;b.strokeStyle=c.scaleLineColor;b.beginPath();b.moveTo(n,p+5);b.lineTo(n,5);b.stroke();b.textAlign="right";b.textBaseline="middle";for(d=0;d<j.steps;d++)b.beginPath(),b.moveTo(n-3,p-(d+1)*k),c.scaleShowGridLines?(b.lineWidth=c.scaleGridLineWidth,
b.strokeStyle=c.scaleGridLineColor,b.lineTo(n+r+5,p-(d+1)*k)):b.lineTo(n-0.5,p-(d+1)*k),b.stroke(),c.scaleShowLabels&&b.fillText(j.labels[d],n-8,p-(d+1)*k)},function(d){function e(b,c){return p-d*v(a.datasets[b].data[c],j,k)}for(var f=0;f<a.datasets.length;f++){b.strokeStyle=a.datasets[f].strokeColor;b.lineWidth=c.datasetStrokeWidth;b.beginPath();b.moveTo(n,p-d*v(a.datasets[f].data[0],j,k));for(var g=1;g<a.datasets[f].data.length;g++)c.bezierCurve?b.bezierCurveTo(n+m*(g-0.5),e(f,g-1),n+m*(g-0.5),
e(f,g),n+m*g,e(f,g)):b.lineTo(n+m*g,e(f,g));b.stroke();c.datasetFill?(b.lineTo(n+m*(a.datasets[f].data.length-1),p),b.lineTo(n,p),b.closePath(),b.fillStyle=a.datasets[f].fillColor,b.fill()):b.closePath();if(c.pointDot){b.fillStyle=a.datasets[f].pointColor;b.strokeStyle=a.datasets[f].pointStrokeColor;b.lineWidth=c.pointDotStrokeWidth;for(g=0;g<a.datasets[f].data.length;g++)b.beginPath(),b.arc(n+m*g,p-d*v(a.datasets[f].data[g],j,k),c.pointDotRadius,0,2*Math.PI,!0),b.fill(),b.stroke()}}},b)},L=function(a,
c,b){var e,h,f,d,g,k,j,l,m,t,r,n,p,s,w=0;g=u;b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily;t=1;for(d=0;d<a.labels.length;d++)e=b.measureText(a.labels[d]).width,t=e>t?e:t;q/a.labels.length<t?(w=45,q/a.labels.length<Math.cos(w)*t?(w=90,g-=t):g-=Math.sin(w)*t):g-=c.scaleFontSize;d=c.scaleFontSize;g=g-5-d;e=Number.MIN_VALUE;h=Number.MAX_VALUE;for(f=0;f<a.datasets.length;f++)for(l=0;l<a.datasets[f].data.length;l++)a.datasets[f].data[l]>e&&(e=a.datasets[f].data[l]),a.datasets[f].data[l]<
h&&(h=a.datasets[f].data[l]);f=Math.floor(g/(0.66*d));d=Math.floor(0.5*(g/d));l=c.scaleShowLabels?c.scaleLabel:"";c.scaleOverride?(j={steps:c.scaleSteps,stepValue:c.scaleStepWidth,graphMin:c.scaleStartValue,labels:[]},z(l,j.labels,j.steps,c.scaleStartValue,c.scaleStepWidth)):j=C(g,f,d,e,h,l);k=Math.floor(g/j.steps);d=1;if(c.scaleShowLabels){b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily;for(e=0;e<j.labels.length;e++)h=b.measureText(j.labels[e]).width,d=h>d?h:d;d+=10}r=q-d-t;m=
Math.floor(r/a.labels.length);s=(m-2*c.scaleGridLineWidth-2*c.barValueSpacing-(c.barDatasetSpacing*a.datasets.length-1)-(c.barStrokeWidth/2*a.datasets.length-1))/a.datasets.length;n=q-t/2-r;p=g+c.scaleFontSize/2;x(c,function(){b.lineWidth=c.scaleLineWidth;b.strokeStyle=c.scaleLineColor;b.beginPath();b.moveTo(q-t/2+5,p);b.lineTo(q-t/2-r-5,p);b.stroke();0<w?(b.save(),b.textAlign="right"):b.textAlign="center";b.fillStyle=c.scaleFontColor;for(var d=0;d<a.labels.length;d++)b.save(),0<w?(b.translate(n+
d*m,p+c.scaleFontSize),b.rotate(-(w*(Math.PI/180))),b.fillText(a.labels[d],0,0),b.restore()):b.fillText(a.labels[d],n+d*m+m/2,p+c.scaleFontSize+3),b.beginPath(),b.moveTo(n+(d+1)*m,p+3),b.lineWidth=c.scaleGridLineWidth,b.strokeStyle=c.scaleGridLineColor,b.lineTo(n+(d+1)*m,5),b.stroke();b.lineWidth=c.scaleLineWidth;b.strokeStyle=c.scaleLineColor;b.beginPath();b.moveTo(n,p+5);b.lineTo(n,5);b.stroke();b.textAlign="right";b.textBaseline="middle";for(d=0;d<j.steps;d++)b.beginPath(),b.moveTo(n-3,p-(d+1)*
k),c.scaleShowGridLines?(b.lineWidth=c.scaleGridLineWidth,b.strokeStyle=c.scaleGridLineColor,b.lineTo(n+r+5,p-(d+1)*k)):b.lineTo(n-0.5,p-(d+1)*k),b.stroke(),c.scaleShowLabels&&b.fillText(j.labels[d],n-8,p-(d+1)*k)},function(d){b.lineWidth=c.barStrokeWidth;for(var e=0;e<a.datasets.length;e++){b.fillStyle=a.datasets[e].fillColor;b.strokeStyle=a.datasets[e].strokeColor;for(var f=0;f<a.datasets[e].data.length;f++){var g=n+c.barValueSpacing+m*f+s*e+c.barDatasetSpacing*e+c.barStrokeWidth*e;b.beginPath();
b.moveTo(g,p);b.lineTo(g,p-d*v(a.datasets[e].data[f],j,k)+c.barStrokeWidth/2);b.lineTo(g+s,p-d*v(a.datasets[e].data[f],j,k)+c.barStrokeWidth/2);b.lineTo(g+s,p);c.barShowStroke&&b.stroke();b.closePath();b.fill()}}},b)},D=window.requestAnimationFrame||window.webkitRequestAnimationFrame||window.mozRequestAnimationFrame||window.oRequestAnimationFrame||window.msRequestAnimationFrame||function(a){window.setTimeout(a,1E3/60)},F={}};
HTML
<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
</head>
<body>
<h1>Live Updating Chart.js</h1>
<canvas id="myChart" width="400" height="150"></canvas>
</body>
</html>
The update() triggers an update of the chart.
chart.update( )
.update(config)
Triggers an update of the chart. This can be safely called after updating the data object. This will update all scales, legends, and then re-render the chart. A config object can be provided with additional configuration for the update process.
update() can be safely called after updating values of one or more existing points within the the data object, rendering the changes in one animated render loop.
// update the first dataset's value of 'March' to be 50
myBarChart.data.datasets[0].bars[2].value = 50;
// animate update of 'March' from 90 to 50.
myBarChart.update();
Here is how to do it in the last version of ChartJs:
setInterval(function(){
chart.data.datasets[0].data[5] = 80;
chart.data.labels[5] = "Newly Added";
chart.update();
}
Look at this clear video
or test it in jsfiddle
You also can use destroy() function. Like this
if( window.myBar!==undefined)
window.myBar.destroy();
var ctx = document.getElementById("canvas").getContext("2d");
window.myBar = new Chart(ctx).Bar(barChartData, {
responsive : true,
});
You just need to change the chartObject.data.datasets value and call update() like this:
chartObject.data.datasets = newData.datasets;
chartObject.data.labels = newData.labels;
chartObject.update();
Remove the canvas dom and add in again.
function renderChart(label,data){
$("#canvas-wrapper").html("").html('<canvas id="storeSends"></canvas>');
var lineChartData = {
labels : label,
datasets : [
{
fillColor : "rgba(49, 195, 166, 0.2)",
strokeColor : "rgba(49, 195, 166, 1)",
pointColor : "rgba(49, 195, 166, 1)",
pointStrokeColor : "#fff",
data : data
}
]
}
var canvas = document.getElementById("storeSends");
var ctx = canvas.getContext("2d");
myLine = new Chart(ctx).Line(lineChartData, {
responsive: true,
maintainAspectRatio: false
});
}
I think the easiest way is to write a function to update your chart including the chart.update()method. Check out this simple example I wrote in jsfiddle for a Bar Chart.
//value for x-axis
var emotions = ["calm", "happy", "angry", "disgust"];
//colours for each bar
var colouarray = ['red', 'green', 'yellow', 'blue'];
//Let's initialData[] be the initial data set
var initialData = [0.1, 0.4, 0.3, 0.6];
//Let's updatedDataSet[] be the array to hold the upadted data set with every update call
var updatedDataSet;
/*Creating the bar chart*/
var ctx = document.getElementById("barChart");
var barChart = new Chart(ctx, {
type: 'bar',
data: {
labels: emotions,
datasets: [{
backgroundColor: colouarray,
label: 'Prediction',
data: initialData
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true,
min: 0,
max: 1,
stepSize: 0.5,
}
}]
}
}
});
/*Function to update the bar chart*/
function updateBarGraph(chart, label, color, data) {
chart.data.datasets.pop();
chart.data.datasets.push({
label: label,
backgroundColor: color,
data: data
});
chart.update();
}
/*Updating the bar chart with updated data in every second. */
setInterval(function() {
updatedDataSet = [Math.random(), Math.random(), Math.random(), Math.random()];
updateBarGraph(barChart, 'Prediction', colouarray, updatedDataSet);
}, 1000);
<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.3.0/Chart.min.js"></script>
<body>
<div>
<h1>Update Bar Chart</h1>
<canvas id="barChart" width="800" height="450"></canvas>
</div>
<script src="barchart.js"></script>
</body>
</head>
</html>
Hope this helps.
If destroy() and clear() is not working (just like what i had experience) you can use jquery to remove the canvas and append it again.
$('#chartAmazon').remove();
$('#chartBar').append('<canvas id="chartAmazon"></canvas>');
var ctxAmazon = $("#chartAmazon").get(0).getContext("2d");
var AmazonChart = new Chart(ctxAmazon, {
type: 'doughnut',
data: dataAmazon,
options: optionsA
});
I don't think it's possible right now.
However that's a feature which should come soon, as the author hinted here:
https://github.com/nnnick/Chart.js/issues/161#issuecomment-20487775
This is an example with ChartJs - 2.9.4
var maximumPoints = 5;// with this variable you can decide how many points are display on the chart
function addData(chart, label, data) {
chart.data.labels.push(label);
chart.data.datasets.forEach((dataset) => {
var d = data[0];
dataset.data.push(d);
data.shift();
});
var canRemoveData = false;
chart.data.datasets.forEach((dataset) => {
if (dataset.data.length > maximumPoints) {
if (!canRemoveData) {
canRemoveData = true;
chart.data.labels.shift();
}
dataset.data.shift();
}
});
chart.update();
}
window.onload = function () {
var canvas = document.getElementById('elm-chart'),
ctx = canvas.getContext('2d');
var myLineChart = new Chart(ctx, {
type: 'line',
data: {
labels: [],
datasets: [
{
data: [],
label: 'Dataset-1',
backgroundColor: "#36a2eb88",
borderColor: "#36a2eb",
},
{
data: [],
label: 'Dataset-2',
backgroundColor: "#ff638488",
borderColor: "#ff6384",
}
],
},
options: {
responsive: false,
maintainAspectRatio: false,
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
var index = 0;
setInterval(function () {
var data = [];
myLineChart.data.datasets.forEach((dataset) => {
data.push(Math.random() * 100);
});
addData(myLineChart, index, data);
index++;
}, 1000);
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.min.js"></script>
<canvas id="elm-chart" width="640" height="480"></canvas>
There are 2 ways to solve it:
chart.update()
Delete existing chart using chart.destroy() and create new chart object.
The simplest way is to replace the canvas element and then call new Chart() again:
function reloadMyChart() {
$('myChart').replaceWith('<canvas id="myChart"></canvas>');
new Chart(document.getElementById("myChart"), {
data: yourChartData,
type: yourChartType,
options: yourChartOptions
});
}
Of course, you must replace yourChartData, yourChartType and yourChartOptions with the correct values required to initialize Chart.js. See Chart.js Docs.
You can call reloadMyChart function on a button click or any other event you need. Probably you'll add parameters to this function and use these to make a REST call to dynamically update your chart, like this:
function reloadMyChart(param1, param2) {
$('myChart').replaceWith('<canvas id="myChart"></canvas>');
$.get("restUrl?param1=" + param1 + "¶m2=" + param2 + ",
function(data) {
// call new Chart() here and use returned data
}
);
Hope it helps! =)
Showing realtime update chartJS
function add_data(chart, label, data)
{
var today = new Date();
var time = today.getHours() + ":" + today.getMinutes() + ":" + today.getSeconds();
myLineChart.data.datasets[0].data.push(Math.random() * 100);
myLineChart.data.datasets[1].data.push(Math.random() * 100);
myLineChart.data.labels.push(time)
myLineChart.update();
}
setInterval(add_data, 10000); //milisecond
full code , you can download in description link
As of 2022 and using ChartJS v3.7.1 you can use the code below.
Note that it is based on the JSBin snippets in doub1ejack's answer but these were not up to date and wouldn't work with the latest ChartJS version, mainly because the path to charts' data changed (now being yourChart._metasets[0]._dataset.data).
var canvas = document.getElementById('updating-chart'),
ctx = canvas.getContext('2d'),
startingData = {
labels: [1, 2, 3, 4, 5, 6, 7],
datasets: [
{
fillColor: "rgba(220,220,220,0.2)",
strokeColor: "rgba(220,220,220,1)",
pointColor: "rgba(220,220,220,1)",
pointStrokeColor: "#fff",
data: [65, 59, 80, 81, 56, 55, 40]
},
{
fillColor: "rgba(151,187,205,0.2)",
strokeColor: "rgba(151,187,205,1)",
pointColor: "rgba(151,187,205,1)",
pointStrokeColor: "#fff",
data: [28, 48, 40, 19, 86, 27, 90]
}
]
};
// Reduce the animation steps for demo clarity.
const myLiveChart = new Chart(ctx, {
type: 'bar',
data: startingData,
options: {
scales: {
y: {
beginAtZero: true
}
},
maintainAspectRatio: false,
}
});
setInterval(function(){
// Get a random index point
var indexToUpdate = Math.round(Math.random() * startingData.labels.length);
// Update one of the points in the second dataset
myLiveChart._metasets[0]._dataset.data[indexToUpdate] = Math.random() * 100;
myLiveChart.update();
}, 5000);
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Updating chart example</title>
<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
</head>
<body>
<canvas id="updating-chart" width="500" height="300"></canvas>
</body>
</html>
You can check instance of Chart by using Chart.instances.
This will give you all the charts instances.
Now you can iterate on that instances and and change the data, which is present inside config.
suppose you have only one chart in your page.
for (var _chartjsindex in Chart.instances) {
/*
* Here in the config your actual data and options which you have given at the
time of creating chart so no need for changing option only you can change data
*/
Chart.instances[_chartjsindex].config.data = [];
// here you can give add your data
Chart.instances[_chartjsindex].update();
// update will rewrite your whole chart with new value
}
My solve was to actually store the charts outside of the state of Vue. Store the charts in a const variable in like a utility.js file. Then I was able to simply do this:
const PVR_CANVASES = {}
//This was my vue method for building the charts
build_metrics() {
this.votingResults.metrics.forEach(metric => {
const el = document.getElementById(metric.metric_data.canvas);
const n_chart = new Chart(el, {
type: 'line',
data: metric.chart.data,
options: {
responsive: true,
maintainAspectRatio: true,
layout: {
autoPadding: false
},
plugins: {
legend: {
display: false,
}
},
scales: {
x: {
display: false
},
y: {
display: false
}
},
elements: {
line: {
tension: 0.4
},
point: {
backgroundColor: 'rgba(0, 0, 0, 0.1)'
}
}
}
});
PVR_CANVASES[metric.chart.id] = n_chart;
})
}
//UPDATE CHART IS THIS SIMPLE
this.votingResults.metrics.forEach(metric => {
const n_chart = PVR_CANVASES[metric.chart.id];
n_chart.data = metric.chart.data;
n_chart.update();
});
So simple, Just replace the chart canvas element.
$('#canvas').replaceWith(' id="canvas" height="200px"
width="368px">');
I'm trying to make a Graph which has to show the Account movement from each Customer.
What I'm trying to do
I've tree lines ;
First line : The minimum balance, if the customer has less than the min. balance, his balance will auto load from his bank account.
Second Line : The current balance
Third Line: The maximum balance : If the customer has more than the max. balance he will become the difference from the system on his bank account.
My Problem
Link to the picture : chartjs tooltip problem
As you see in the tooltip are the all 3 values. The values of the straight lines are irrelevant for the customer because the Limits (max and min are setted from the customer his own) .
To achieve this you can extend the line graph to add an option to show/hide tool-tips on a per dataset basses. The annoying thing is there are only a few changes but whole methods have to be overridden to get the changes in there so the below looks like a lot but its basically 3 changes to the following methods
Initialize - added option to store showTooltip option in each point
getPointsAtEvent - added check to make sure we want to disaply a tool tip when getting points
showTooltip - added check again to make sure we want to dispaly a tool tip
to then use it the chart is set up the same but instead you make it a LineTooltip (thats what i have called the extended chart) and pass anextra option in the datasets call showToolip.
datasets: [{
label: "My First dataset",
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,0.8)",
highlightFill: "rgba(220,220,220,0.75)",
highlightStroke: "rgba(220,220,220,1)",
showTooltip: false, //NEW OPTION DON"T NEED TO INCLUDE IT IF YOU WANT TO DISPLAY BUT WON"T HURT IF YOU DO
data: [15, 10, 10, 10, 10, 10, 10]
}, {
label: "My second dataset",
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,0.8)",
highlightFill: "rgba(220,220,220,0.75)",
highlightStroke: "rgba(220,220,220,1)",
showTooltip: false, //NEW OPTION DON"T NEED TO INCLUDE IT IF YOU WANT TO DISPLAY BUT WON"T HURT IF YOU DO
data: [100, 100, 100, 100, 100, 100, 100]
}, {
label: "My third dataset",
fillColor: "rgba(151,187,205,0.5)",
strokeColor: "rgba(151,187,205,0.8)",
highlightFill: "rgba(151,187,205,0.75)",
highlightStroke: "rgba(151,187,205,1)",
data: [28, 48, 40, 19, 86, 27, 90]
}]
i have added bigger comment banners in the below code to try and highlight where the changes got made. I have also added this feature to my fork of chartjs as this could be useful to more people https://github.com/leighquince/Chart.js, using this you can just use a normal line chart and add the showTooltip
Below is the example of extending the Line into a custom chart to include this feature, ive called in LineTooltip as but could be called anything you like that.
Chart.types.Line.extend({
name: "LineTooltip",
/*
* we have to add one item in the init so need to rewrite it again here with the one edit
*/
initialize: function(data) {
//have to get the helpers as we are using this outside chart where it was declared
var helpers = Chart.helpers;
//Declare the extension of the default point, to cater for the options passed in to the constructor
this.PointClass = Chart.Point.extend({
strokeWidth: this.options.pointDotStrokeWidth,
radius: this.options.pointDotRadius,
display: this.options.pointDot,
hitDetectionRadius: this.options.pointHitDetectionRadius,
ctx: this.chart.ctx,
inRange: function(mouseX) {
return (Math.pow(mouseX - this.x, 2) < Math.pow(this.radius + this.hitDetectionRadius, 2));
}
});
this.datasets = [];
//Set up tooltip events on the chart
if (this.options.showTooltips) {
helpers.bindEvents(this, this.options.tooltipEvents, function(evt) {
var activePoints = (evt.type !== 'mouseout') ? this.getPointsAtEvent(evt) : [];
this.eachPoints(function(point) {
point.restore(['fillColor', 'strokeColor']);
});
helpers.each(activePoints, function(activePoint) {
activePoint.fillColor = activePoint.highlightFill;
activePoint.strokeColor = activePoint.highlightStroke;
});
this.showTooltip(activePoints);
});
}
//Iterate through each of the datasets, and build this into a property of the chart
helpers.each(data.datasets, function(dataset) {
var datasetObject = {
label: dataset.label || null,
fillColor: dataset.fillColor,
strokeColor: dataset.strokeColor,
pointColor: dataset.pointColor,
pointStrokeColor: dataset.pointStrokeColor,
showTooltip: dataset.showTooltip,
points: []
};
this.datasets.push(datasetObject);
helpers.each(dataset.data, function(dataPoint, index) {
//Add a new point for each piece of data, passing any required data to draw.
datasetObject.points.push(new this.PointClass({
/*
* set wether to show the tooltip or not, left this as being able to be undfined
* and default to true
*/
showTooltip: dataset.showTooltip === undefined ? true : dataset.showTooltip,
value: dataPoint,
label: data.labels[index],
datasetLabel: dataset.label,
strokeColor: dataset.pointStrokeColor,
fillColor: dataset.pointColor,
highlightFill: dataset.pointHighlightFill || dataset.pointColor,
highlightStroke: dataset.pointHighlightStroke || dataset.pointStrokeColor
}));
}, this);
this.buildScale(data.labels);
this.eachPoints(function(point, index) {
helpers.extend(point, {
x: this.scale.calculateX(index),
y: this.scale.endPoint
});
point.save();
}, this);
}, this);
this.render();
},
/*
* need to edit how points at event works so it only uses points that we want to show the tool tip for
*/
getPointsAtEvent: function(e) {
//have to get the helpers as we are using this outside chart where it was declared
var helpers = Chart.helpers;
var pointsArray = [],
eventPosition = helpers.getRelativePosition(e);
helpers.each(this.datasets, function(dataset) {
helpers.each(dataset.points, function(point) {
if (point.inRange(eventPosition.x, eventPosition.y) && point.showTooltip) pointsArray.push(point);
});
}, this);
return pointsArray;
},
/*
* also need to change how the core showTooltip functions as otherwise, it trys to be helpful
* and grab any points it thinks also need to be displayed
*/
showTooltip: function(ChartElements, forceRedraw) {
//have to get the helpers as we are using this outside chart where it was declared
var helpers = Chart.helpers;
var each = helpers.each;
var indexOf = helpers.indexOf;
var min = helpers.min;
var max = helpers.min;
// Only redraw the chart if we've actually changed what we're hovering on.
if (typeof this.activeElements === 'undefined') this.activeElements = [];
var isChanged = (function(Elements) {
var changed = false;
if (Elements.length !== this.activeElements.length) {
changed = true;
return changed;
}
each(Elements, function(element, index) {
if (element !== this.activeElements[index]) {
changed = true;
}
}, this);
return changed;
}).call(this, ChartElements);
if (!isChanged && !forceRedraw) {
return;
} else {
this.activeElements = ChartElements;
}
this.draw();
if (ChartElements.length > 0) {
// If we have multiple datasets, show a MultiTooltip for all of the data points at that index
if (this.datasets && this.datasets.length > 1) {
var dataArray,
dataIndex;
for (var i = this.datasets.length - 1; i >= 0; i--) {
dataArray = this.datasets[i].points || this.datasets[i].bars || this.datasets[i].segments;
dataIndex = indexOf(dataArray, ChartElements[0]);
if (dataIndex !== -1) {
break;
}
}
var tooltipLabels = [],
tooltipColors = [],
medianPosition = (function(index) {
// Get all the points at that particular index
var Elements = [],
dataCollection,
xPositions = [],
yPositions = [],
xMax,
yMax,
xMin,
yMin;
helpers.each(this.datasets, function(dataset) {
dataCollection = dataset.points || dataset.bars || dataset.segments;
/*
*check to make sure we want to show the point
*/
if (dataCollection[dataIndex] && dataCollection[dataIndex].hasValue() && (dataCollection[dataIndex].showTooltip === undefined || dataCollection[dataIndex].showTooltip)) {
Elements.push(dataCollection[dataIndex]);
}
});
helpers.each(Elements, function(element) {
xPositions.push(element.x);
yPositions.push(element.y);
//Include any colour information about the element
tooltipLabels.push(helpers.template(this.options.multiTooltipTemplate, element));
tooltipColors.push({
fill: element._saved.fillColor || element.fillColor,
stroke: element._saved.strokeColor || element.strokeColor
});
}, this);
yMin = min(yPositions);
yMax = max(yPositions);
xMin = min(xPositions);
xMax = max(xPositions);
return {
x: (xMin > this.chart.width / 2) ? xMin : xMax,
y: (yMin + yMax) / 2
};
}).call(this, dataIndex);
new Chart.MultiTooltip({
x: medianPosition.x,
y: medianPosition.y,
xPadding: this.options.tooltipXPadding,
yPadding: this.options.tooltipYPadding,
xOffset: this.options.tooltipXOffset,
fillColor: this.options.tooltipFillColor,
textColor: this.options.tooltipFontColor,
fontFamily: this.options.tooltipFontFamily,
fontStyle: this.options.tooltipFontStyle,
fontSize: this.options.tooltipFontSize,
titleTextColor: this.options.tooltipTitleFontColor,
titleFontFamily: this.options.tooltipTitleFontFamily,
titleFontStyle: this.options.tooltipTitleFontStyle,
titleFontSize: this.options.tooltipTitleFontSize,
cornerRadius: this.options.tooltipCornerRadius,
labels: tooltipLabels,
legendColors: tooltipColors,
legendColorBackground: this.options.multiTooltipKeyBackground,
title: ChartElements[0].label,
chart: this.chart,
ctx: this.chart.ctx
}).draw();
} else {
each(ChartElements, function(Element) {
var tooltipPosition = Element.tooltipPosition();
new Chart.Tooltip({
x: Math.round(tooltipPosition.x),
y: Math.round(tooltipPosition.y),
xPadding: this.options.tooltipXPadding,
yPadding: this.options.tooltipYPadding,
fillColor: this.options.tooltipFillColor,
textColor: this.options.tooltipFontColor,
fontFamily: this.options.tooltipFontFamily,
fontStyle: this.options.tooltipFontStyle,
fontSize: this.options.tooltipFontSize,
caretHeight: this.options.tooltipCaretSize,
cornerRadius: this.options.tooltipCornerRadius,
text: template(this.options.tooltipTemplate, Element),
chart: this.chart
}).draw();
}, this);
}
}
return this;
},
});
var ctx = document.getElementById("chart").getContext("2d");
var data = {
labels: ["January", "February", "March", "April", "May", "June", "July"],
datasets: [{
label: "My First dataset",
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,0.8)",
highlightFill: "rgba(220,220,220,0.75)",
highlightStroke: "rgba(220,220,220,1)",
showTooltip: false, //TO USE JUST ADD THIS NEW OPTION ONLY REALLY NEEDS TO PRESENT IF SETTING TO FALSE
data: [15, 10, 10, 10, 10, 10, 10]
}, {
label: "My second dataset",
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,0.8)",
highlightFill: "rgba(220,220,220,0.75)",
highlightStroke: "rgba(220,220,220,1)",
showTooltip: false, //TO USE JUST ADD THIS NEW OPTION ONLY REALLY NEEDS TO PRESENT IF SETTING TO FALSE
data: [100, 100, 100, 100, 100, 100, 100]
}, {
label: "My third dataset",
fillColor: "rgba(151,187,205,0.5)",
strokeColor: "rgba(151,187,205,0.8)",
highlightFill: "rgba(151,187,205,0.75)",
highlightStroke: "rgba(151,187,205,1)",
data: [28, 48, 40, 19, 86, 27, 90]
}]
};
var myBarChart = new Chart(ctx).LineTooltip(data);
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/1.0.2/Chart.min.js"></script>
<canvas id="chart" width="600px"></canvas>
and a fiddle if you find that easy to view http://jsfiddle.net/leighking2/1Lammwpt/