Dynamically Update Values of a Chartjs Chart

Dynamically update values of a chartjs chart

Update: Looks like chartjs has been updated (see comment below). There are some examples up that look very nice:

  1. Here's an example of updating a line chart using new data: http://jsbin.com/yitep/5/edit
  2. 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
  );
});

// ChartJS
var Chart=function(s){function v(a,c,b){a=A((a-c.graphMin)/(c.steps*c.stepValue),1,0);return b*c.steps*a}function x(a,c,b,e){function h(){g+=f;var k=a.animation?A(d(g),null,0):1;e.clearRect(0,0,q,u);a.scaleOverlay?(b(k),c()):(c(),b(k));if(1>=g)D(h);else if("function"==typeof a.onAnimationComplete)a.onAnimationComplete()}var f=a.animation?1/A(a.animationSteps,Number.MAX_VALUE,1):1,d=B[a.animationEasing],g=a.animation?0:1;"function"!==typeof c&&(c=function(){});D(h)}function C(a,c,b,e,h,f){var d;a=
Math.floor(Math.log(e-h)/Math.LN10);h=Math.floor(h/(1*Math.pow(10,a)))*Math.pow(10,a);e=Math.ceil(e/(1*Math.pow(10,a)))*Math.pow(10,a)-h;a=Math.pow(10,a);for(d=Math.round(e/a);d<b||d>c;)a=d<b?a/2:2*a,d=Math.round(e/a);c=[];z(f,c,d,h,a);return{steps:d,stepValue:a,graphMin:h,labels:c}}function z(a,c,b,e,h){if(a)for(var f=1;f<b+1;f++)c.push(E(a,{value:(e+h*f).toFixed(0!=h%1?h.toString().split(".")[1].length:0)}))}function A(a,c,b){return!isNaN(parseFloat(c))&&isFinite(c)&&a>c?c:!isNaN(parseFloat(b))&&
isFinite(b)&&a<b?b:a}function y(a,c){var b={},e;for(e in a)b[e]=a[e];for(e in c)b[e]=c[e];return b}function E(a,c){var b=!/\W/.test(a)?F[a]=F[a]||E(document.getElementById(a).innerHTML):new Function("obj","var p=[],print=function(){p.push.apply(p,arguments);};with(obj){p.push('"+a.replace(/[\r\t\n]/g," ").split("<%").join("\t").replace(/((^|%>)[^\t]*)'/g,"$1\r").replace(/\t=(.*?)%>/g,"',$1,'").split("\t").join("');").split("%>").join("p.push('").split("\r").join("\\'")+"');}return p.join('');");return c?
b(c):b}var r=this,B={linear:function(a){return a},easeInQuad:function(a){return a*a},easeOutQuad:function(a){return-1*a*(a-2)},easeInOutQuad:function(a){return 1>(a/=0.5)?0.5*a*a:-0.5*(--a*(a-2)-1)},easeInCubic:function(a){return a*a*a},easeOutCubic:function(a){return 1*((a=a/1-1)*a*a+1)},easeInOutCubic:function(a){return 1>(a/=0.5)?0.5*a*a*a:0.5*((a-=2)*a*a+2)},easeInQuart:function(a){return a*a*a*a},easeOutQuart:function(a){return-1*((a=a/1-1)*a*a*a-1)},easeInOutQuart:function(a){return 1>(a/=0.5)?
0.5*a*a*a*a:-0.5*((a-=2)*a*a*a-2)},easeInQuint:function(a){return 1*(a/=1)*a*a*a*a},easeOutQuint:function(a){return 1*((a=a/1-1)*a*a*a*a+1)},easeInOutQuint:function(a){return 1>(a/=0.5)?0.5*a*a*a*a*a:0.5*((a-=2)*a*a*a*a+2)},easeInSine:function(a){return-1*Math.cos(a/1*(Math.PI/2))+1},easeOutSine:function(a){return 1*Math.sin(a/1*(Math.PI/2))},easeInOutSine:function(a){return-0.5*(Math.cos(Math.PI*a/1)-1)},easeInExpo:function(a){return 0==a?1:1*Math.pow(2,10*(a/1-1))},easeOutExpo:function(a){return 1==
a?1:1*(-Math.pow(2,-10*a/1)+1)},easeInOutExpo:function(a){return 0==a?0:1==a?1:1>(a/=0.5)?0.5*Math.pow(2,10*(a-1)):0.5*(-Math.pow(2,-10*--a)+2)},easeInCirc:function(a){return 1<=a?a:-1*(Math.sqrt(1-(a/=1)*a)-1)},easeOutCirc:function(a){return 1*Math.sqrt(1-(a=a/1-1)*a)},easeInOutCirc:function(a){return 1>(a/=0.5)?-0.5*(Math.sqrt(1-a*a)-1):0.5*(Math.sqrt(1-(a-=2)*a)+1)},easeInElastic:function(a){var c=1.70158,b=0,e=1;if(0==a)return 0;if(1==(a/=1))return 1;b||(b=0.3);e<Math.abs(1)?(e=1,c=b/4):c=b/(2*
Math.PI)*Math.asin(1/e);return-(e*Math.pow(2,10*(a-=1))*Math.sin((1*a-c)*2*Math.PI/b))},easeOutElastic:function(a){var c=1.70158,b=0,e=1;if(0==a)return 0;if(1==(a/=1))return 1;b||(b=0.3);e<Math.abs(1)?(e=1,c=b/4):c=b/(2*Math.PI)*Math.asin(1/e);return e*Math.pow(2,-10*a)*Math.sin((1*a-c)*2*Math.PI/b)+1},easeInOutElastic:function(a){var c=1.70158,b=0,e=1;if(0==a)return 0;if(2==(a/=0.5))return 1;b||(b=1*0.3*1.5);e<Math.abs(1)?(e=1,c=b/4):c=b/(2*Math.PI)*Math.asin(1/e);return 1>a?-0.5*e*Math.pow(2,10*
(a-=1))*Math.sin((1*a-c)*2*Math.PI/b):0.5*e*Math.pow(2,-10*(a-=1))*Math.sin((1*a-c)*2*Math.PI/b)+1},easeInBack:function(a){return 1*(a/=1)*a*(2.70158*a-1.70158)},easeOutBack:function(a){return 1*((a=a/1-1)*a*(2.70158*a+1.70158)+1)},easeInOutBack:function(a){var c=1.70158;return 1>(a/=0.5)?0.5*a*a*(((c*=1.525)+1)*a-c):0.5*((a-=2)*a*(((c*=1.525)+1)*a+c)+2)},easeInBounce:function(a){return 1-B.easeOutBounce(1-a)},easeOutBounce:function(a){return(a/=1)<1/2.75?1*7.5625*a*a:a<2/2.75?1*(7.5625*(a-=1.5/2.75)*
a+0.75):a<2.5/2.75?1*(7.5625*(a-=2.25/2.75)*a+0.9375):1*(7.5625*(a-=2.625/2.75)*a+0.984375)},easeInOutBounce:function(a){return 0.5>a?0.5*B.easeInBounce(2*a):0.5*B.easeOutBounce(2*a-1)+0.5}},q=s.canvas.width,u=s.canvas.height;window.devicePixelRatio&&(s.canvas.style.width=q+"px",s.canvas.style.height=u+"px",s.canvas.height=u*window.devicePixelRatio,s.canvas.width=q*window.devicePixelRatio,s.scale(window.devicePixelRatio,window.devicePixelRatio));this.PolarArea=function(a,c){r.PolarArea.defaults={scaleOverlay:!0,
scaleOverride:!1,scaleSteps:null,scaleStepWidth:null,scaleStartValue:null,scaleShowLine:!0,scaleLineColor:"rgba(0,0,0,.1)",scaleLineWidth:1,scaleShowLabels:!0,scaleLabel:"<%=value%>",scaleFontFamily:"'Arial'",scaleFontSize:12,scaleFontStyle:"normal",scaleFontColor:"#666",scaleShowLabelBackdrop:!0,scaleBackdropColor:"rgba(255,255,255,0.75)",scaleBackdropPaddingY:2,scaleBackdropPaddingX:2,segmentShowStroke:!0,segmentStrokeColor:"#fff",segmentStrokeWidth:2,animation:!0,animationSteps:100,animationEasing:"easeOutBounce",
animateRotate:!0,animateScale:!1,onAnimationComplete:null};var b=c?y(r.PolarArea.defaults,c):r.PolarArea.defaults;return new G(a,b,s)};this.Radar=function(a,c){r.Radar.defaults={scaleOverlay:!1,scaleOverride:!1,scaleSteps:null,scaleStepWidth:null,scaleStartValue:null,scaleShowLine:!0,scaleLineColor:"rgba(0,0,0,.1)",scaleLineWidth:1,scaleShowLabels:!1,scaleLabel:"<%=value%>",scaleFontFamily:"'Arial'",scaleFontSize:12,scaleFontStyle:"normal",scaleFontColor:"#666",scaleShowLabelBackdrop:!0,scaleBackdropColor:"rgba(255,255,255,0.75)",
scaleBackdropPaddingY:2,scaleBackdropPaddingX:2,angleShowLineOut:!0,angleLineColor:"rgba(0,0,0,.1)",angleLineWidth:1,pointLabelFontFamily:"'Arial'",pointLabelFontStyle:"normal",pointLabelFontSize:12,pointLabelFontColor:"#666",pointDot:!0,pointDotRadius:3,pointDotStrokeWidth:1,datasetStroke:!0,datasetStrokeWidth:2,datasetFill:!0,animation:!0,animationSteps:60,animationEasing:"easeOutQuart",onAnimationComplete:null};var b=c?y(r.Radar.defaults,c):r.Radar.defaults;return new H(a,b,s)};this.Pie=function(a,
c){r.Pie.defaults={segmentShowStroke:!0,segmentStrokeColor:"#fff",segmentStrokeWidth:2,animation:!0,animationSteps:100,animationEasing:"easeOutBounce",animateRotate:!0,animateScale:!1,onAnimationComplete:null};var b=c?y(r.Pie.defaults,c):r.Pie.defaults;return new I(a,b,s)};this.Doughnut=function(a,c){r.Doughnut.defaults={segmentShowStroke:!0,segmentStrokeColor:"#fff",segmentStrokeWidth:2,percentageInnerCutout:50,animation:!0,animationSteps:100,animationEasing:"easeOutBounce",animateRotate:!0,animateScale:!1,
onAnimationComplete:null};var b=c?y(r.Doughnut.defaults,c):r.Doughnut.defaults;return new J(a,b,s)};this.Line=function(a,c){r.Line.defaults={scaleOverlay:!1,scaleOverride:!1,scaleSteps:null,scaleStepWidth:null,scaleStartValue:null,scaleLineColor:"rgba(0,0,0,.1)",scaleLineWidth:1,scaleShowLabels:!0,scaleLabel:"<%=value%>",scaleFontFamily:"'Arial'",scaleFontSize:12,scaleFontStyle:"normal",scaleFontColor:"#666",scaleShowGridLines:!0,scaleGridLineColor:"rgba(0,0,0,.05)",scaleGridLineWidth:1,bezierCurve:!0,
pointDot:!0,pointDotRadius:4,pointDotStrokeWidth:2,datasetStroke:!0,datasetStrokeWidth:2,datasetFill:!0,animation:!0,animationSteps:60,animationEasing:"easeOutQuart",onAnimationComplete:null};var b=c?y(r.Line.defaults,c):r.Line.defaults;return new K(a,b,s)};this.Bar=function(a,c){r.Bar.defaults={scaleOverlay:!1,scaleOverride:!1,scaleSteps:null,scaleStepWidth:null,scaleStartValue:null,scaleLineColor:"rgba(0,0,0,.1)",scaleLineWidth:1,scaleShowLabels:!0,scaleLabel:"<%=value%>",scaleFontFamily:"'Arial'",
scaleFontSize:12,scaleFontStyle:"normal",scaleFontColor:"#666",scaleShowGridLines:!0,scaleGridLineColor:"rgba(0,0,0,.05)",scaleGridLineWidth:1,barShowStroke:!0,barStrokeWidth:2,barValueSpacing:5,barDatasetSpacing:1,animation:!0,animationSteps:60,animationEasing:"easeOutQuart",onAnimationComplete:null};var b=c?y(r.Bar.defaults,c):r.Bar.defaults;return new L(a,b,s)};var G=function(a,c,b){var e,h,f,d,g,k,j,l,m;g=Math.min.apply(Math,[q,u])/2;g-=Math.max.apply(Math,[0.5*c.scaleFontSize,0.5*c.scaleLineWidth]);
d=2*c.scaleFontSize;c.scaleShowLabelBackdrop&&(d+=2*c.scaleBackdropPaddingY,g-=1.5*c.scaleBackdropPaddingY);l=g;d=d?d:5;e=Number.MIN_VALUE;h=Number.MAX_VALUE;for(f=0;f<a.length;f++)a[f].value>e&&(e=a[f].value),a[f].value<h&&(h=a[f].value);f=Math.floor(l/(0.66*d));d=Math.floor(0.5*(l/d));m=c.scaleShowLabels?c.scaleLabel:null;c.scaleOverride?(j={steps:c.scaleSteps,stepValue:c.scaleStepWidth,graphMin:c.scaleStartValue,labels:[]},z(m,j.labels,j.steps,c.scaleStartValue,c.scaleStepWidth)):j=C(l,f,d,e,h,
m);k=g/j.steps;x(c,function(){for(var a=0;a<j.steps;a++)if(c.scaleShowLine&&(b.beginPath(),b.arc(q/2,u/2,k*(a+1),0,2*Math.PI,!0),b.strokeStyle=c.scaleLineColor,b.lineWidth=c.scaleLineWidth,b.stroke()),c.scaleShowLabels){b.textAlign="center";b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily;var e=j.labels[a];if(c.scaleShowLabelBackdrop){var d=b.measureText(e).width;b.fillStyle=c.scaleBackdropColor;b.beginPath();b.rect(Math.round(q/2-d/2-c.scaleBackdropPaddingX),Math.round(u/2-k*(a+
1)-0.5*c.scaleFontSize-c.scaleBackdropPaddingY),Math.round(d+2*c.scaleBackdropPaddingX),Math.round(c.scaleFontSize+2*c.scaleBackdropPaddingY));b.fill()}b.textBaseline="middle";b.fillStyle=c.scaleFontColor;b.fillText(e,q/2,u/2-k*(a+1))}},function(e){var d=-Math.PI/2,g=2*Math.PI/a.length,f=1,h=1;c.animation&&(c.animateScale&&(f=e),c.animateRotate&&(h=e));for(e=0;e<a.length;e++)b.beginPath(),b.arc(q/2,u/2,f*v(a[e].value,j,k),d,d+h*g,!1),b.lineTo(q/2,u/2),b.closePath(),b.fillStyle=a[e].color,b.fill(),
c.segmentShowStroke&&(b.strokeStyle=c.segmentStrokeColor,b.lineWidth=c.segmentStrokeWidth,b.stroke()),d+=h*g},b)},H=function(a,c,b){var e,h,f,d,g,k,j,l,m;a.labels||(a.labels=[]);g=Math.min.apply(Math,[q,u])/2;d=2*c.scaleFontSize;for(e=l=0;e<a.labels.length;e++)b.font=c.pointLabelFontStyle+" "+c.pointLabelFontSize+"px "+c.pointLabelFontFamily,h=b.measureText(a.labels[e]).width,h>l&&(l=h);g-=Math.max.apply(Math,[l,1.5*(c.pointLabelFontSize/2)]);g-=c.pointLabelFontSize;l=g=A(g,null,0);d=d?d:5;e=Number.MIN_VALUE;
h=Number.MAX_VALUE;for(f=0;f<a.datasets.length;f++)for(m=0;m<a.datasets[f].data.length;m++)a.datasets[f].data[m]>e&&(e=a.datasets[f].data[m]),a.datasets[f].data[m]<h&&(h=a.datasets[f].data[m]);f=Math.floor(l/(0.66*d));d=Math.floor(0.5*(l/d));m=c.scaleShowLabels?c.scaleLabel:null;c.scaleOverride?(j={steps:c.scaleSteps,stepValue:c.scaleStepWidth,graphMin:c.scaleStartValue,labels:[]},z(m,j.labels,j.steps,c.scaleStartValue,c.scaleStepWidth)):j=C(l,f,d,e,h,m);k=g/j.steps;x(c,function(){var e=2*Math.PI/
a.datasets[0].data.length;b.save();b.translate(q/2,u/2);if(c.angleShowLineOut){b.strokeStyle=c.angleLineColor;b.lineWidth=c.angleLineWidth;for(var d=0;d<a.datasets[0].data.length;d++)b.rotate(e),b.beginPath(),b.moveTo(0,0),b.lineTo(0,-g),b.stroke()}for(d=0;d<j.steps;d++){b.beginPath();if(c.scaleShowLine){b.strokeStyle=c.scaleLineColor;b.lineWidth=c.scaleLineWidth;b.moveTo(0,-k*(d+1));for(var f=0;f<a.datasets[0].data.length;f++)b.rotate(e),b.lineTo(0,-k*(d+1));b.closePath();b.stroke()}c.scaleShowLabels&&
(b.textAlign="center",b.font=c.scaleFontStyle+" "+c.scaleFontSize+"px "+c.scaleFontFamily,b.textBaseline="middle",c.scaleShowLabelBackdrop&&(f=b.measureText(j.labels[d]).width,b.fillStyle=c.scaleBackdropColor,b.beginPath(),b.rect(Math.round(-f/2-c.scaleBackdropPaddingX),Math.round(-k*(d+1)-0.5*c.scaleFontSize-c.scaleBackdropPaddingY),Math.round(f+2*c.scaleBackdropPaddingX),Math.round(c.scaleFontSize+2*c.scaleBackdropPaddingY)),b.fill()),b.fillStyle=c.scaleFontColor,b.fillText(j.labels[d],0,-k*(d+
1)))}for(d=0;d<a.labels.length;d++){b.font=c.pointLabelFontStyle+" "+c.pointLabelFontSize+"px "+c.pointLabelFontFamily;b.fillStyle=c.pointLabelFontColor;var f=Math.sin(e*d)*(g+c.pointLabelFontSize),h=Math.cos(e*d)*(g+c.pointLabelFontSize);b.textAlign=e*d==Math.PI||0==e*d?"center":e*d>Math.PI?"right":"left";b.textBaseline="middle";b.fillText(a.labels[d],f,-h)}b.restore()},function(d){var e=2*Math.PI/a.datasets[0].data.length;b.save();b.translate(q/2,u/2);for(var g=0;g<a.datasets.length;g++){b.beginPath();
b.moveTo(0,d*-1*v(a.datasets[g].data[0],j,k));for(var f=1;f<a.datasets[g].data.length;f++)b.rotate(e),b.lineTo(0,d*-1*v(a.datasets[g].data[f],j,k));b.closePath();b.fillStyle=a.datasets[g].fillColor;b.strokeStyle=a.datasets[g].strokeColor;b.lineWidth=c.datasetStrokeWidth;b.fill();b.stroke();if(c.pointDot){b.fillStyle=a.datasets[g].pointColor;b.strokeStyle=a.datasets[g].pointStrokeColor;b.lineWidth=c.pointDotStrokeWidth;for(f=0;f<a.datasets[g].data.length;f++)b.rotate(e),b.beginPath(),b.arc(0,d*-1*
v(a.datasets[g].data[f],j,k),c.pointDotRadius,2*Math.PI,!1),b.fill(),b.stroke()}b.rotate(e)}b.restore()},b)},I=function(a,c,b){for(var e=0,h=Math.min.apply(Math,[u/2,q/2])-5,f=0;f<a.length;f++)e+=a[f].value;x(c,null,function(d){var g=-Math.PI/2,f=1,j=1;c.animation&&(c.animateScale&&(f=d),c.animateRotate&&(j=d));for(d=0;d<a.length;d++){var l=j*a[d].value/e*2*Math.PI;b.beginPath();b.arc(q/2,u/2,f*h,g,g+l);b.lineTo(q/2,u/2);b.closePath();b.fillStyle=a[d].color;b.fill();c.segmentShowStroke&&(b.lineWidth=
c.segmentStrokeWidth,b.strokeStyle=c.segmentStrokeColor,b.stroke());g+=l}},b)},J=function(a,c,b){for(var e=0,h=Math.min.apply(Math,[u/2,q/2])-5,f=h*(c.percentageInnerCutout/100),d=0;d<a.length;d++)e+=a[d].value;x(c,null,function(d){var k=-Math.PI/2,j=1,l=1;c.animation&&(c.animateScale&&(j=d),c.animateRotate&&(l=d));for(d=0;d<a.length;d++){var m=l*a[d].value/e*2*Math.PI;b.beginPath();b.arc(q/2,u/2,j*h,k,k+m,!1);b.arc(q/2,u/2,j*f,k+m,k,!0);b.closePath();b.fillStyle=a[d].color;b.fill();c.segmentShowStroke&&
(b.lineWidth=c.segmentStrokeWidth,b.strokeStyle=c.segmentStrokeColor,b.stroke());k+=m}},b)},K=function(a,c,b){var e,h,f,d,g,k,j,l,m,t,r,n,p,s=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?(s=45,q/a.labels.length<Math.cos(s)*t?(s=90,g-=t):g-=Math.sin(s)*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-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>

Updating chartJS with dynamic data

This answer will depend on how you are trying to update the information. Assuming you are using exactly as you gave, you will put a timer for every 3 hours and run this function:

function updateWeatherChart(){
    WeatherChart.data.datasets[0].data = [1, 2, 3, 4];
    WeatherChart.update();  
}

You can have something that, like in the documentation says, runs through the data and deletes it first. Or, you can just reassign it with the new information you want to update the existing chart with.

Keep in mind that instead of [1, 2, 3, 4] you will have to run code before to get the new information and replace the array with your own array. [1, 2, 3, 4] was just a test case.

Dynamically update chart in chartJs

EDIT
http://www.chartjs.org/docs/

The chartjs library is now the most updated and useful. Use the link above.

I think what you need to do is download the updated Chart.Js library, ChartNew.js at: https://github.com/FVANCOP/ChartNew.js/ . This updated library has an update function among many other improvements that make things much easier. You can download the zip file using the link above and find tons great example files that will help you figure out most issues. There is also some pretty good documentation at: https://github.com/FVANCOP/ChartNew.js/wiki/100.Available_options .

I will add a full example from the above library that you can copy and paste into an html file in order to see exactly how you can create a dynamic chart. Just take a look and play around with the examples until you start to see how things work.

     <!doctype html>

<!--[if lte IE 8]><SCRIPT src='source/excanvas.js'></script><![endif]--><SCRIPT src='../ChartNew.js'></script>
<SCRIPT src='../Add-ins/format.js'></script>

<SCRIPT>

function setColor(area,data,config,i,j,animPct,value)
{
  if(value > 35)return("rgba(220,0,0,"+animPct);
  else return("rgba(0,220,0,"+animPct);

}

var charJSPersonnalDefaultOptions = { decimalSeparator : "," , thousandSeparator : ".", roundNumber : "none", graphTitleFontSize: 2 };

defCanvasWidth=600;
defCanvasHeight=300;

var mydata = {
    labels : [],
    datasets : [
        {
            fillColor : "rgba(220,220,220,0.5)",
            strokeColor : "rgba(220,220,220,1)",
            pointColor : "rgba(220,220,220,1)",
            pointstrokeColor : "yellow",
            xPos : [],
            data : [],
                title : "2014"
        }
    ]
}               

var startWithDataset =1;
var startWithData =1;

var opt = {
      animationStartWithDataset : startWithDataset,
      animationStartWithData : startWithData,
      animation : true,
      animationLeftToRight : true,
      animationSteps : 20,
      animationEasing: "linear",
      canvasBorders : true,
      canvasBordersWidth : 3,
      canvasBordersColor : "black",
      graphTitle : "animation With Update",
      legend : true,
//      inGraphDataShow : true,
      annotateDisplay : true,
      onAnimationComplete : startUpdate,
      graphTitleFontSize: 18, 
    responsive : true,
    scaleOverride: true,
    scaleSteps: 10,
    scaleStepWidth: 10,
    scaleStartValue: 0,
    fmtXLabel : "fmttime hh:mm:ss",
    animationCount: 1,
    animationPauseTime : 0,
    animationBackward: true

};

function startUpdate(ctx, config, data, tp, count) {
    setTimeout(function (){updt(ctx,data,config);}, 1000+Math.random()*500);
//  setTimeout(function (){updt(ctx,data,config);}, 1000);
};

function updt(ctx,data,config) {
    updtData(data);
        config.animationSteps = 50*data.datasets[0].xPos.length;
    config.animationStartValue=1-(2/data.datasets[0].xPos.length);
    deleteHighLight(ctx,data);
    updateChart(ctx,data,config,true,true);
}

function updtData(data) {
    var i;

    var t=new Date();

    var coeff = 1000 ;
    var rounded = new Date(Math.round(t.getTime() / coeff) * coeff + coeff);

    for(i=0;i<10;i++)
    {
        var t2 = new Date(rounded - (18-2*i) * 1000);
        data.labels[i]=t2;
    } 

    data.xBegin=data.labels[0];
    data.xEnd=data.labels[9];

    data.datasets[0].xPos[data.datasets[0].xPos.length]=t;
    vl=Math.random()*100;
    data.datasets[0].data[data.datasets[0].data.length]=vl;

    // remove data outside first time;
    while(data.datasets[0].xPos[0]<data.labels[0]) {
        data.datasets[0].xPos.splice(0,1);
        data.datasets[0].data.splice(0,1);
    }

}

updtData(mydata);
updtData(mydata);
updtData(mydata);
mydata.datasets[0].xPos[0]=new Date(mydata.datasets[0].xPos[0]-2000);
mydata.datasets[0].xPos[1]=new Date(mydata.datasets[0].xPos[1]-1000);

</SCRIPT>

<html>
  <meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
    <head>
        <title>Demo ChartNew.js</title>
    </head>
    <body>

  <center>
    <FONT SIZE=6><B>Demo of ChartNew.js !</B></FONT>    <BR>

    <script>

    document.write("<canvas id=\"canvas_Line\" height=\""+defCanvasHeight+"\" width=\""+defCanvasWidth+"\"></canvas>");
window.onload = function() {
    var myLine = new Chart(document.getElementById("canvas_Line").getContext("2d")).Line(mydata,opt);

 }
    </script>
  </body>
</html>

The provided code example is taken directly from the GitHub download folder. They provide a great deal of examples to help make sense of the the documentation.

Update data of chartjs chart

The first time you run your function, you're placing the chart (a.k.a "the returned value of new Chart()") inside the outterChart variable.

If you instantiate that variable outside of your function (in this case, outside chartRender), its value will be preserved across multiple runs of the function, and you'll be able to choose whether or not to create the chart or just update it based on current value of outterChart.

In principle:

let outterChart; // undefined at first...

let chartRender = () => {
  ...
  http.onLoad = () => {
    ...

    if (outterChart) {
      // update outterChart here. it has already been created

      /* 
       * The update syntax depends on the structure of the data returned by server
       * docs here: https://www.chartjs.org/docs/3.5.0/developers/updates.html
       */

    } else {
      outterChart = new Chart({
        ...
      });
    }
  }
}

Edit: after having a look at your mcve, here's the bit that you need:

  ...
  if (outterChart) {
    data.datasets.forEach((ds, i) => {
      outterChart.data.datasets[i].data = ds.data;
    })
    outterChart.update();
  } else {
    outterChart = new Chart(chart, { ... })
  }
...

I could have simply done:

if (outterChart) {
  outterChart.data = data;
} else {
  outterChart = new Chart(chart, { ... })
}

..., but this would have completely replaced your datasets, instead of updating their data. If you replace any of the current datasets, the chart will perform an "enter" animation (will animate from scratch); whereas if you only replace the dataset's data it will animate from current values to the new ones.


Related Topics

Invariant Violation: _Registercomponent(...): Target Container Is Not a Dom Element

How Is JavaScript Single Threaded

How to Stop a Window.Setinterval in JavaScript

Convert Time Interval Given in Seconds into More Human Readable Form

Jasmine: Async Callback Was Not Invoked Within Timeout Specified by Jasmine.Default_Timeout_Interval

How to Access a Child's State in React

What Is the Meaning of Symbol $ in Jquery

How to Filter Array When Object Key Value Is in Array

Why Use Object.Prototype.Hasownproperty.Call(Myobj, Prop) Instead of Myobj.Hasownproperty(Prop)

Lodash - Difference Between .Extend()/.Assign() and .Merge()

Sorting Objects by Property Values

How to Filter JSON Data in JavaScript or Jquery

How to Set the Prototype of a JavaScript Object That Has Already Been Instantiated

Js Search in Object Values

Using Number as "Index" (JSON)

Using Jquery to Find an Element at a Particular Position

Dynamically Arrange Some Elements Around a Circle

Jquery - Script Tags in the HTML Are Parsed Out by Jquery and Not Executed


Leave a reply



Submit