@berryv/g2-ssr-node

The tool for G2 spec's SSR(Server-Side Rendering) in Node.js.

Installing

Install via a package manager such as Yarn or NPM.

$ npm install @berryv/g2-ssr-node

Use CLI to convert a G2 specification file named in bar.json into a png file named bar.png.

$ g2-ssr-node g2png -i ./bar.json -o bar.png

In Node, use render to convert a G2 specification into a png file named bar.png.

const fs = require("fs");
const { render } = require("@berry/g2-ssr-node");

const spec = {
  type: "interval",
  data: [
    { genre: "Sports", sold: 275 },
    { genre: "Strategy", sold: 115 },
    { genre: "Action", sold: 120 },
    { genre: "Shooter", sold: 350 },
    { genre: "Other", sold: 150 },
  ],
  encode: { x: "genre", y: "sold", color: "genre" },
};

render(spec).then((canvas) => {
  const out = fs.createWriteStream("./bar.png");
  const stream = canvas.createJPEGStream();
  stream.pipe(out);
  stream.on("finish", () => console.log("Convert successfully!"));
});

Development

$ npm i
$ npm link
$ npm run build
$ npm run test:png

API Reference

• CLI - Convert spec in command line.
• Node - Convert spec in Node.js.

CLI

# subcommand.g2png

Usage: g2-ssr-node g2png [options]

Convert a G2 spec to an PNG image

Options:
  -i, --input <filename>   filename for the input spec
  -o, --output <filename>  filename for the output image
  -h, --help               display help for command

For example, convert a G2 specification file named in bar.json into a png file named bar.png:

$ g2-ssr-node g2png -i ./bar.json -o bar.png

# subcommand.g2jpeg

Usage: g2-ssr-node g2pdf [options]

Convert a G2 spec to a PDF

Options:
  -i, --input <filename>   filename for the input spec
  -o, --output <filename>  filename for the output pdf
  -h, --help               display help for command

For example, convert a G2 specification file named in bar.json into a png file named bar.jpeg:

$ g2-ssr-node g2jpeg -i ./bar.json -o bar.jpeg

# subcommand.g2pdf

Usage: g2-ssr-node g2jpeg [options]

Convert a G2 spec to an JPEG image

Options:
  -i, --input <filename>   filename for the input spec
  -o, --output <filename>  filename for the output image
  -h, --help               display help for command

For example, convert a G2 specification file named in bar.json into a png file named bar.pdf:

$ g2-ssr-node g2pdf -i ./bar.json -o bar.pdf

Node

# node.renderImage(options)

Renders a G2 specification into a image canvas in node-canvas resolved by a promise. Then creates a stream from the returned canvas and write into a file, supporting the following stream types:

• canvas.createPNGStream
• canvas.createJPEGStream

For example, convert a G2 specification into a png file named bar.png.

const fs = require("fs");
const { render } = require("@berry/g2-ssr-node");

const spec = {
  type: "interval",
  data: [
    { genre: "Sports", sold: 275 },
    { genre: "Strategy", sold: 115 },
    { genre: "Action", sold: 120 },
    { genre: "Shooter", sold: 350 },
    { genre: "Other", sold: 150 },
  ],
  encode: { x: "genre", y: "sold", color: "genre" },
};

renderImage(spec).then((canvas) => {
  const out = fs.createWriteStream("./bar.png");
  const stream = canvas.createJPEGStream();
  stream.pipe(out);
  stream.on("finish", () => console.log("Convert successfully!"));
});

# node.renderPDF(options)

Renders a G2 specification into a pdf canvas in node-canvas resolved by a promise. Then creates a pdf stream from the returned canvas and write into a file:

• canvas.createPDFStream

For example, convert a G2 specification into a png file named bar.png.

const fs = require("fs");
const { render } = require("@berry/g2-ssr-node");

const spec = {
  type: "interval",
  data: [
    { genre: "Sports", sold: 275 },
    { genre: "Strategy", sold: 115 },
    { genre: "Action", sold: 120 },
    { genre: "Shooter", sold: 350 },
    { genre: "Other", sold: 150 },
  ],
  encode: { x: "genre", y: "sold", color: "genre" },
};

renderPDF(spec).then((canvas) => {
  const out = fs.createWriteStream("./bar.png");
  const stream = canvas.createPDFStream();
  stream.pipe(out);
  stream.on("finish", () => console.log("Convert successfully!"));
});