@nodepit/svg-to-img

svg-to-img

A node.js library to convert SVGs to images built with Puppeteer.

NOTE: This is a fork from Etienne Martin’s svg-to-img which adds the possibility to connect to a Puppeteer endpoint (see here).

Getting Started

Installation

To use svg-to-img in your project, run:

npm install @nodepit/svg-to-img -S

Starting from v3.0.0, Chromium will no longer automatically be downloaded when installing this dependency (instead of depending on puppetteer, the library now depends on puppeteer-core; see here). We assume that you either have an existing local or remote Chromium, or that you explicitly install puppeteer within your project to to have Chromium downloaded.

Debian

If you're planning on running svg-to-img on Debian, you will need to manually install the following dependencies:

#!/bin/bash

apt-get update
apt-get install -yq gconf-service libasound2 libatk1.0-0 libc6 libcairo2 libcups2 libdbus-1-3 \
  libexpat1 libfontconfig1 libgcc1 libgconf-2-4 libgdk-pixbuf2.0-0 libglib2.0-0 libgtk-3-0 libnspr4 \
  libpango-1.0-0 libpangocairo-1.0-0 libstdc++6 libx11-6 libx11-xcb1 libxcb1 libxcomposite1 \
  libxcursor1 libxdamage1 libxext6 libxfixes3 libxi6 libxrandr2 libxrender1 libxss1 libxtst6 \
  ca-certificates fonts-liberation libappindicator1 libnss3 lsb-release xdg-utils wget

Usage

Example - converting a svg to png:

const svgToImg = require("svg-to-img");

(async () => {
  const image = await svgToImg.from("<svg xmlns='http://www.w3.org/2000/svg'/>").toPng();
  
  console.log(image);
})();

Example - converting a svg to jpeg and saving the image as example.jpeg:

const svgToImg = require("svg-to-img");

(async () => {
  await svgToImg.from("<svg xmlns='http://www.w3.org/2000/svg'/>").toJpeg({
    path: "./example.jpeg"
  });
})();

Example - resizing a svg proportionally and converting it to webp:

const svgToImg = require("svg-to-img");

(async () => {
  const image = await svgToImg.from("<svg xmlns='http://www.w3.org/2000/svg'/>").toWebp({
    width: 300
  });
  
  console.log(image);
})();

Example - converting a svg to base64-encoded png:

const svgToImg = require("svg-to-img");

(async () => {
  const image = await svgToImg.from("<svg xmlns='http://www.w3.org/2000/svg'/>").toPng({
    encoding: "base64"
  });
  
  console.log(image);
})();

Example - connect to Puppeteer browserWSEndpoint:

const svgToImg = require("svg-to-img");
const convert = svgToImg.connect({
  browserWSEndpoint: "ws://localhost:3000"
});

(async () => {
  const image = await convert.from("<svg xmlns='http://www.w3.org/2000/svg'/>").toPng();

  console.log(image);
})();

API Documentation

svgToImg.from(svg)

• svg <Buffer|string> SVG markup to be converted.
• returns: <[Svg]> a new Svg object.

The method returns a svg instance based on the given argument.

svgToImg.connect(options)

• options <[Object]> Puppeteer connect options object which will typically contain a browserWSEndpoint property.
• returns: <[SvgToImg]> an instance which is connected with the specified Puppeteer endpoint.

Use this method if you want to connect to a running Puppeteer endpoint (see here). Note that the actual connection is established lazily; this means this method will always return, even when the given browserWSEndpoint cannot be reached -- in this case, errors will be thrown later when calling one of the to functions.

svg.to([options])

• options <[Object]> Options object which might have the following properties:
  • path <[string]> The file path to save the image to. The image type will be inferred from file extension. If path is a relative path, then it is resolved relative to current working directory. If no path is provided, the image won't be saved to the disk.
  • type <[string]> Specify image type, can be either png, jpeg or webp. Defaults to png.
  • quality <[number]> The quality of the image, between 0-1. Defaults to 1. Not applicable to png images.
  • width <[number]> width of the output image. Defaults to the natural width of the SVG.
  • height <[number]> height of the output image. Defaults to the natural height of the SVG.
  • clip <[Object]> An object which specifies clipping region of the output image. Should have the following fields:
    • x <[number]> x-coordinate of top-left corner of clip area
    • y <[number]> y-coordinate of top-left corner of clip area
    • width <[number]> width of clipping area
    • height <[number]> height of clipping area
  • background <[string]> background color applied to the output image, must be a valid CSS color value.
  • encoding <[string]> Specify encoding, can be either base64, utf8, binary or hex. Returns a Buffer if this option is omitted.
• returns: <[Promise]<Buffer|String>> Promise which resolves to the output image.

svg.toPng([options])

• options <[Object]> Optional options object that can have the same properties as the to method except for the type property.
• returns: <[Promise]<Buffer|String>> Promise which resolves to the png image.

This method is simply a shorthand for the to method.

svg.toJpeg([options])

• options <[Object]> Optional options object that can have the same properties as the to method except for the type property.
• returns: <[Promise]<Buffer|String>> Promise which resolves to the jpeg image.

This method is simply a shorthand for the to method.

svg.toWebp([options])

• options <[Object]> Optional options object that can have the same properties as the to method except for the type property.
• returns: <[Promise]<Buffer|String>> Promise which resolves to the webp image.

This method is simply a shorthand for the to method.

Built with

• node.js - Cross-platform JavaScript run-time environment for executing JavaScript code server-side.
• Puppeteer - Headless Chrome Node API.
• TypeScript - Typed superset of JavaScript that compiles to plain JavaScript.
• Jest - Delightful JavaScript Testing.

Contributing

When contributing to this project, please first discuss the change you wish to make via issue, email, or any other method with the owners of this repository before making a change.

Update the README.md with details of changes to the library.

Execute npm run test and update the tests if needed.

Authors

• Etienne Martin - Initial work - etiennemartin.ca
• Philipp Katz - Connect to browser endpoint - gitlab.com/qqilihq

License

This project is licensed under the MIT License - see the LICENSE file for details.