README

A PHP client for the quickchart.io chart image API.

Installation

Use the QuickChart.php library in this project, or install from packagist.

composer require ianw/quickchart

Usage

This library provides a QuickChart class. Import and instantiate it. Then set properties on it and specify a Chart.js config:

$chart = new QuickChart(array(
  'width' => 500,
  'height' => 300
));

$chart->setConfig('{
  type: "bar",
  data: {
    labels: ["Hello world", "Test"],
    datasets: [{
      label: "Foo",
      data: [1, 2]
    }]
  }
}');

Use getUrl() on your QuickChart object to get the encoded URL that renders your chart:

echo $chart->getUrl();
// https://quickchart.io/chart?c=%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%2C2%5D%7D%5D%7D%7D&w=500&h=300

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):

echo $chart->getShortUrl();
// https://quickchart.io/chart/render/f-a1d3e804-dfea-442c-88b0-9801b9808401

The URLs will render an image of a chart:

Creating the chart object

The QuickChart class constructor accepts an array containing the following keys. All are optional and can be set after object creation:

config: array or string

The actual Chart.js chart configuration.

width: int

Width of the chart image in pixels. Defaults to 500

height: int

Height of the chart image in pixels. Defaults to 300

format: string

Format of the chart. Defaults to png.

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: float

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.

version: string

The Chart.js version to use. See documentation for supported versions.

apiKey: string

Your QuickChart API key, if you have one.

Setting properties

Each option above has an associated function call that you can invoke on your QuickChart object:

• setConfig($config)
• setWidth($width)
• setHeight($height)
• setFormat($format)
• setBackgroundColor($backgroundColor)
• setDevicePixelRatio($devicePixelRatio)
• setVersion($version)
• setApiKey($apiKey)

Getting URLs

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

getUrl: string

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

getShortUrl: string

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 outputs

toBinary: binary string

Returns a binary string representing the chart image

toFile($path: string)

Write the image to a file

For example:

$chart->toFile('/tmp/myfile.png')

More examples

Checkout the examples directory to see other usage.

Troubleshooting

PHP5 users: This package requires curl and json modules.

sslv3 handshake alert failure: You are using an outdated version of curl. Please upgrade curl on your machine.