chartist-to-image


Generating chart images from "Chartist" charts was a bit of challange, but now by using this module you can render images of your chartist chart without any hassle.

Installation

``
$ npm install chartist-to-image --save
`

Usage

Following will describes to how to use chartist-to-image on Angular 2-5,
but also you can take insight from following to implement in js

Import



import chartist2image from 'chartist-to-image';
or
import * as chartist2image from 'chartist-to-image';

Calling

chartistChart = new Chartist.Line/Pie('chart name',data,chartOptions);
let options = {
outputImage: {
quality: 0.35,
bgcolor: '#000000',
name: 'my-chartist-charts'
},
format: 'jpeg',
download: true,
log: true,

};
let base64;
async genImage(){
this.chartist2image = chartist2image;
await chartist2image.toJpeg('HTML div ID which contains chartist chart',options,chartistChart).then(
(res) => {
base64 = res;
console.log('Logged >>>>>>>>',base64);
}
);
}
It is better to use chartist-to-image with async and wait since it takes some time to render the image.

After it generates the 'base64' value you can easily use it on an HTML
like


Currently chartist-to-image generates only .jpeg's, but in future we will add other formats as well.

Attention!

(if you are passing the Chartist instance to chartist2image.toJpeg() you don't want to worry about this)
Most of the image rendering packages not compatible with "Chartist" because
chartist uses <foreignObject> in their svgs.
So becuase of that you have to replace <foreignObject> by using <text>
This can be easily done like,
> var chartistLineChart = new Chartist.Line('.ct-chart', data, options);
> chartistLineChart.supportsForeignObject = false;

if you are using angular 2-5
> this.chartistLineChart = new Chartist.Line('.ct-chart', data, options);
> this.chartistLineChart.supportsForeignObject = false;

Or you can pass your Chartist chart instance to chartist2image function, it will do that for you.

chartistChart = new Chartist.Line/Pie('chart name',data,options);
async genImage(){
this.chartist2image = chartist2image;
await chartist2image.toJpeg('pie-chart-content',options,chartistChart).then(
(res) => {
base64 = res;
console.log('Logged >>>>>>>>',base64)
});}

Options

'chartist-to-image' accepts a 'json' object which is having following attributes

| Attribute | Default |Other |
|----------------|-------------------------------|-----------------------------|
|outputImage|json Attributes quality: 1.00,bgcolor: '#000000', name: 'Chart Image' |'quality: 0-1 bgcolor: {#anyColor} name: {your's name to chart} |
|format |.jpeg |More formats in further releases |
|download |true auto download the image after rendering|false|

Credits

The rendering of the image done suing 'dom-to-image' library. It is a great module to render images from HTML and SVGs. 'chartist-to-image' has been modified according to support for Chartist charts rendering. Since the source is embedded to this module, you don't have to download it as a dependency.