restcharts

RESTCharts

Generate PNG images of charts easily through a simple REST-like API.

Charts generated by Highcharts

Example: https://api.restcharts.com/chart/area?data=1,2,6,4,10,7,4,5,2,9,8&color=f00

API

$ curl -X GET https://api.restcharts.com/chart/:type[?parameter1=val1&parameter2=val2]

or

$ curl -X POST https://api.restcharts.com/chart/:type -d '{"parameter1": "val1", "parameter2": "val2", ...}'

Parameters

Simple Params

URL parameters

• type: The type of the chart you want to generate. See all types here.

Body/query string parameters

• data: Comma-delimited list of your data that needs to be charted. This is a required parameter if the raw config option (see Advanced below) is not provided or it is but a series array within the raw config is not provided.
• color: The color of the line/bar/column/etc. of the chart.
• bg: The background color of the area surrounding the chart (default: transparent, i.e. rgba(0, 0, 0, 0))
• height: The height of the generated chart.
• width: The width of the generated chart.
• opacity: If an area chart (or variation), will be the opacity of the area.
• linewidth: If a line or spline chart, the line width of the lines.

Advanced Params

If you want to generate a chart using any Highcharts options (the relevant options are the ones in the Highcharts.chart() method), you can provide a raw config object with any available options you'd like to provide for the chart type desired. Any configuration you have in the raw parameter will override the default options. Examples can be seen here.

• raw: The JSON serialized config object. If the data parameter is not provided, a series array of data needs to be included here.

Default Configuration

The default Highcharts configuration object that is used if only simple parameters above are provided is as follows. We perform a deep Object.assign() with this object as the target and the raw object overwriting anything in this object if it's provided in a request:

{
  chart: {
    type: `type`,
    backgroundColor: `bg`,
    margin: [ 0, 0, 0, 0 ],
    height: `height`,
    width: `width`
  },
  plotOptions: {
    area: {
      fillOpacity: `opacity`
    }
  },
  credits: {
    enabled: false
  },
  xAxis: {
    visible: false
  },
  yAxis: {
    visible: false
  },
  legend: {
    enabled: false
  },
  exporting: {
    enabled: false
  },
  title: {
    text: '',
  },
  series: [{
    lineWidth: `linewidth`,
    color: `color`,
    data: `data`.map(d => ({ y: parseVal(d, 'integer'), marker: { enabled: false }}))
  }]
}

Development

Environment Variables

The following environment variables is required for the app to be deployed and Highcharts installed correctly without problems. Please make sure you have a Highcharts license per their licensing requirements :)

1. ACCEPT_HIGHCHARTS_LICENSE=YES

Build

$ # To build the distribution files for the server
$ gulp build
$ # To run the dev server via nodemon
$ npm run dev
$ # To run tests
$ npm test

AWS Lambda

As of 2020-01-26, AWS Lambda's Runtime image lacks a dependency for PhantomJS to work which is what highcharts-export-server uses under the hood (see the error). To work around this issue follow these instructions before deploying to AWS Lambda.

Don't forget about setting the FONTCONFIG_PATH environment to /var/task/lib in your Lambda environment variables.

https://github.com/tarkal/highchart-lambda-export-server#building-from-scratch