Suresh
Suresh

Reputation: 105

How to create datasets dynamically for chart.js Line chart?

I want to create a Line chart with multiple datasets dynamically in the chart.js library.

I am able to assign the data dynamically. But I want to create the datasets itself dynamically. I saw the link below:

How to add the elements dynamically from the html table for chart.js

and tried this :

var datasetValue = [];
for (var j = 0; j < count; j++) {
datasetValue[j] = [
{
fillColor: 'rgba(220,220,220,0.5)',
strokeColor :'rgba(220,220,220,1)' ,
title :'2013',
data : [Math.round(Math.random() * 100),Math.round(Math.random() * 100)-10]
}]
}

var mydata = {
datasets : datasetValue
}

Here the count value is 3 and I want to display the 3 lines in the chart and the count value will vary. Even though the chart line color and title will be the same, I want to display the line first and will change the rest once this is solved.

I tried to access the data like so :

alert("Datasets:"+mydata.datasets[0].data);

It should show the data of the first dataset but it's showing undefined.

However in the below case:

var mydata1 = {
labels : ["January","February","March","April","May","June","July"],
datasets : [
    {
        fillColor : "rgba(220,220,220,0.5)",
        strokeColor : "rgba(220,220,220,1)",
        data : [95,53,99,73,27,82,40],
        title : "2014"
    },
    {
        fillColor : "rgba(151,187,205,0.5)",
        strokeColor : "rgba(151,187,205,1)",
        data : [35,43,59,31,50,66,55],
        title : "2013"
    }
 ]
}

alert("Datasets:"+mydata1.datasets[0].data);

I am able to get the data of first dataset. Could anyone please give me the solution?

Upvotes: 9

Views: 43103

Answers (2)

Bear GRiZZLY Xi
Bear GRiZZLY Xi

Reputation: 315

I think you are looking for something like the following solution. http://jsfiddle.net/5m63232a/

var datasetValue = [];
var count = 10;
for (var j=0; j<count; j++) {
    datasetValue[j] = {
        fillColor: 'rgba(220,220,220,0.5)',
        strokeColor :'rgba(220,220,220,1)',
        title :'2013',
        data : [Math.round(Math.random() * 100),Math.round(Math.random() * 100)-10]
    }
}
var mydata = {
    datasets : datasetValue
}
alert("Datasets: "+mydata.datasets[0].data);

Upvotes: 14

Bhuwan Prasad Upadhyay
Bhuwan Prasad Upadhyay

Reputation: 3056

Create service to fetch json formt like :

labels : ["January","February","March","April","May","June","July"],
        datasets : [
            {
                label: "My First dataset",
                fillColor : "rgba(220,220,220,0.2)",
                strokeColor : "rgba(220,220,220,1)",
                pointColor : "rgba(220,220,220,1)",
                pointStrokeColor : "#fff",
                pointHighlightFill : "#fff",
                pointHighlightStroke : "rgba(220,220,220,1)",
                data : [randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor()]
            },
            {
                label: "My Second dataset",
                fillColor : "rgba(151,187,205,0.2)",
                strokeColor : "rgba(151,187,205,1)",
                pointColor : "rgba(151,187,205,1)",
                pointStrokeColor : "#fff",
                pointHighlightFill : "#fff",
                pointHighlightStroke : "rgba(151,187,205,1)",
                data : [randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor()]
            }
        ]  

Then add following javascript code

var j = [];
$.ajax({
    type: 'GET',
    url: 'http://' + window.location.host.toString() + "/path",
    dataType: 'json',
    success: function (data) {
       j = data;
    },
    async: false
 });
 var chartData = {
     labels: j.labels,
     datasets: j.datasets
 };
 window.onload = function () {
     var ctx = document.getElementById("canvas").getContext("2d");
     window.myLine = new Chart(ctx).Line(chartData, {
         responsive: true,
         animation: true,
         tooltipFillColor: "rgba(0,0,0,0.8)",
         multiTooltipTemplate: "<%= datasetLabel %> - <%=value %>"
     });
 }

Upvotes: 6

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