ReferenceError: HTMLCanvasElement is not defined

Trying to apply this library to code ported from the front end:

const ChartjsNode = require('chartjs-node')

let chart = new ChartjsNode(300, 200)

let result = require('./data.json')

let data = {
  labels: result.map(d => d.date[ 2 ] + '-' + d.date[ 1 ]),
  datasets: [
    {
      label: 'x',
      backgroundColor: 'rgba(255, 99, 132, 0.7)',
      borderColor: 'rgba(255, 99, 132, 0.7)',
      data: result.map(d => d.x)
    },
    {
      label: 'y',
      backgroundColor: 'rgba(54, 162, 235, 0.7)',
      borderColor: 'rgba(54, 162, 235, 0.7)',
      data: result.map(d => d.y)
    },
    {
      label: 'z',
      backgroundColor: 'rgba(255, 206, 86, 0.7)',
      borderColor: 'rgba(255, 206, 86, 0.7)',
      data: result.map(d => d.z)
    }
  ]
}

let options = {
  fill: false,
  legend: {
    position: 'bottom'
  },
  elements: {
    line: {
      tension: 0,
      fill: false
    }
  }
}

chart.drawChart({ type: 'line', data: data, options: options })
  .then(() => {
    chart.writeImageToFile('image/png', './chart.png')
    chart.destroy()
  })
  .catch(error => console.log(error))

This results in ReferenceError: HTMLCanvasElement is not defined.

[sedouard]

Published an updated version chartjs-node@1.1.1 with the updated peerDependency. Originally I had chart.js as a peerDependency because I wanted to give some flexibility on the version of chart.js you could use with this package 😕.

We’ll see if we can figure out what’s going on with the newer versions of chart.js.

[sedouard]

Not sure whats different in chart.js@2.40 vs chart.js@2.30. To be honest that’s just the version I tested against and set CI up for. I’ll change the peerDependencies to use chart.js@2.3.*. So that the npm install indicates an unmet dependency.

Won’t have time to see what the deal is with 2.4.0. But I’ll open another issue to support it.