The file lib/highcharts-convert.js is a PhantomJS script to convert SVG or Highcharts JSON options objects to chart images. It is ideal for batch processing Highcharts configurations for attaching to emails or reports. An online demo with a GUI can be viewed at export.highcharts.com/demo.

Note The Highcharts files are subjected to the Highcharts License.

Installation

• You can just install the module globally (preferred) or locally, and run it as a service.

# Global
sudo npm install -g highcharts-phantomjs
highcharts-phantomjs start
info: [highcharts-convert]    Started converter on 127.0.0.1:3030 (PID: 9351)

# Local
npm install highcharts-phantomjs
cd node_modules/highcharts-phantomjs
npm start
info: [highcharts-convert]    Started converter on 127.0.0.1:3030 (PID: 8342)

• Alternatively, you could clone this repository and run phantomjs manually.

git clone https://github.com/nfantone/highcharts-export-server
cd highcharts-export-server
npm install --production --no-optional
phantomjs lib/highcharts-convert.js -host 127.0.0.1 -port 3030

For this option to work, you need to have phantomjs binary in your PATH (see http://phantomjs.org/download.html).

Usage

Usage: highcharts-phantomjs start [-h HOST][-p PORT] -- [options]

Commands:
  start  Starts highcharts-convert HTTP server

Options:
  -h, --hostname, --host  Hostname of the server          [default: "127.0.0.1"]
  -p, --port              Port the server will listen on         [default: 3030]
  --help                  Show help                                    [boolean]
  --version               Show version number                          [boolean]

Options

Besides -h (hostname) and -p (port number), any other arguments specified after -- will be passed as is to the phantomjs script on lib/highcharts-convert.js.

The following are all the available options.

-infile

The file to convert, assumes it's either a JSON file, the script checks for the input file to have the extension '.json', or otherwise it assumes it to be an svg file.

-outfile

The file to output. Must be a filename with the extension .jpg, .png .pdf or .svg.

-scale

To set the zoomFactor of the page rendered by PhantomJS. For example, if the chart.width option in the chart configuration is set to 600 and the scale is set to 2, the output raster image will have a pixel width of 1200. So this is a convenient way of increasing the resolution without decreasing the font size and line widths in the chart. This is ignored if the -width parameter is set.

-width

Set the exact pixel width of the exported image or pdf. This overrides the -scale parameter.

-constr

The constructor name. Can be one of Chart or StockChart. This depends on whether you want to generate Highstock or basic Highcharts.

-callback

Filename of the callback. The callback is a function which will be called in the constructor of Highcharts to be executed on chart load. All code of the callback must be enclosed by a function. See this example of contents of the callback file:

function(chart) {
    chart.renderer.arc(200, 150, 100, 50, -Math.PI, 0).attr({
        fill : '#FCFFC5',
        stroke : 'black',
        'stroke-width' : 1
     }).add();
}

API

After starting the converter server, it will listen for POST request. You can use the same parameters as for command line usage, but wrap them in a JSON structure.

Here is an example of a valid request, given a JSON body in some file:

// example-request.json
{
    "infile": "{xAxis: {categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']},series: [{data: [29.9, 71.5, 106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4]}]};",
    "callback": "function(chart) {chart.renderer.arc(200, 150, 100, 50, -Math.PI, 0).attr({fill : '#FCFFC5',stroke : 'black','stroke-width' : 1}).add();}",
    "constr": "Chart"
}

highcharts-phantomjs start -p 3003
info: [highcharts-convert]    Started converter on 127.0.0.1:3030 (PID: 1350)

# On another terminal
curl -XPOST http://localhost:3003 -H 'Content-Type: application/json' -d @example-request.json