quickchartgo

quickchart-go

Go client for the quickchart.io chart API.

Installation

go get github.com/henomis/quickchart-go

Usage

This package is designed to implement quickchart.io API. Import and instantiate it. Then set properties on it and specify a Chart.js config:

chartConfig := `{
		type: 'bar',
		data: {
			labels: ['Q1', 'Q2', 'Q3', 'Q4'],
			datasets: [{
			label: 'Users',
			data: [50, 60, 70, 180]
			}]
		}
	}`

qc := quickchartgo.New()

qc.Config = chartConfig

qc.Width = 500;
qc.Height = 300;
qc.Version = "2.9.4";

Use GetUrl() on your Chart object to get the encoded URL that renders your chart:

fmt.Println(qc.GetUrl());
// https://quickchart.io/chart?c=%7B%22chart%22%3A+%7B%22type%22%3A+%22bar%22%2C+%22data%22%3A+%7B%22labels%22%3A+%5B%22Hello+world%22%2C+%22Test%22%5D%2C+%22datasets%22%3A+%5B%7B%22label%22%3A+%22Foo%22%2C+%22data%22%3A+%5B1%2C+2%5D%7D%5D%7D%7D%7D&w=600&h=300&bkg=%23ffffff&devicePixelRatio=2.0&f=png

If you have a long or complicated chart, use GetShortUrl() to get a fixed-length URL using the quickchart.io web service (note that these URLs only persist for a short time unless you have a subscription):

fmt.Println(qc.GetShortUrl());
// https://quickchart.io/chart/render/f-a1d3e804-dfea-442c-88b0-9801b9808401

The URLs will render an image of a chart:

Customizing your chart

You can set the following properties:

Config: string

The actual Chart.js chart configuration.

Width: int64

Width of the chart image in pixels. Defaults to 500

Height: int64

Height of the chart image in pixels. Defaults to 300

BackgroundColor: string

The background color of the chart. Any valid HTML color works. Defaults to #ffffff (white). Also takes rgb, rgba, and hsl values.

DevicePixelRatio: float64

The device pixel ratio of the chart. This will multiply the number of pixels by the value. This is usually used for retina displays. Defaults to 1.0.

Format: string

The output format of the chart. Defaults to "png"

Version: string

Chart.js version (not required)

Key: string

API key (not required)

Creating chart URLs

There are a few ways to get a URL for your chart object.

GetUrl(): (string, error)

Returns a URL that will display the chart image when loaded.

GetShortUrl(): (string, error)

Uses the quickchart.io web service to create a fixed-length chart URL that displays the chart image. Returns a URL such as https://quickchart.io/chart/render/f-a1d3e804-dfea-442c-88b0-9801b9808401.

Note that short URLs expire after a few days for users of the free service. You can subscribe to keep them around longer.

Other methods

Write(output io.Writer) error

Write your chart to the output io.Writer

More examples

Checkout the examples folder to see other usage.