quickchartgo

README

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.

Documentation

Index

• type Chart
  • func New() *Chart
  • func (qc *Chart) GetShortUrl() (string, error)
  • func (qc *Chart) GetUrl() (string, error)
  • func (qc *Chart) Write(output io.Writer) error

Types

type Chart

type Chart struct {
	Width             int64   `json:"width"`
	Height            int64   `json:"height"`
	DevicePixelRation float64 `json:"devicePixelRatio"`
	Format            string  `json:"format"`
	BackgroundColor   string  `json:"backgroundColor"`
	Key               string  `json:"key"`
	Version           string  `json:"version,omitempty"`
	Config            string  `json:"chart"`

	Scheme  string        `json:"-"`
	Host    string        `json:"-"`
	Port    int64         `json:"-"`
	Timeout time.Duration `json:"-"`
}

func New

func New() *Chart

func (*Chart) GetShortUrl

func (qc *Chart) GetShortUrl() (string, error)

func (*Chart) GetUrl

func (qc *Chart) GetUrl() (string, error)

func (*Chart) Write

func (qc *Chart) Write(output io.Writer) error