Add data to chart dynamically - Javascript Chart.js

Javascript examples for Chart.js:Chart Data

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Description

Add data to chart dynamically

Demo Code

ResultView the demo in separate window 

<html>
   <head> 
      <title>ChartJS Line Chart</title> 
      <meta name="viewport" content="width=device-width, initial-scale=1"> 
      <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.3.0/Chart.js"></script> 
      <style id="compiled-css" type="text/css">

canvas { background-color : #eee;
}


      </style> 
      <script type="text/javascript">
    window.onload=function(){// w w  w . java2s .  c om
// Init chart
const values = []
const ctx = document.getElementById('chartContainer').getContext('2d');
const chart = new Chart(ctx, {
  type: 'line',
  data: {
    labels: ['start'],
    datasets: [
       {
         label: 'mm of rain',
         data: [1],
         borderWidth: 1
       }
      ]
  }
});
// Push 1 item every 100ms (10 Hz), simulates
// your data coming through at a faster
// rate than you can render
setInterval(() => {
   values.push(Math.random())
}, 100)
// Pull last 4 items every 1 second (1 Hz)
setInterval(() => {
  // splice last 4 items, add them to the chart's data
   values.splice(values.length - 4, 4)
     .forEach((value, index) => {
      chart.data.labels.push(index)
      chart.data.datasets[0].data.push(value)
    })
  // finally, command the chart to update once!
  chart.update()
}, 1000)
    }

      </script> 
   </head> 
   <body>  
      <canvas id="chartContainer" width="600" height="400"></canvas>   
   </body>
</html>

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