yUML to SVG

This project is a fork of jaime-olivares/yuml-diagram. You might want to check it out if you are more interested in a synchronous version of the API or you want to use an older version of Node.js.

Allows the creation of offline UML diagrams based on the yUML Syntax.

Support

• Node.js v12+ (yuml2svg v5 uses ECMAScript modules, support is still experimental at the time of writing).
• Browser support through import maps or bundling (WebPack, Rollup, etc.).
• Unofficial support for Node.js v10 LTS (with the --experimental-modules and --experimental-worker CLI flags).
• Experimental support for Deno.

Installation

You can install it with yarn:

yarn global add yuml2svg # For CLI usage
yarn add yuml2svg # As local dependency

Or with npm:

npm --global install yuml2svg # For CLI usage
npm install yuml2svg # As local dependency

Features

• Currently, the following diagram types are supported:
  • Class
  • Activity
  • Use-case
  • State
  • Deployment
  • Package
  • Sequence
• Additional directives for altering diagram type and orientation
• Embedded rendering engine: No need to call an external web service

yUML syntax

Please refer to the wiki page.

Usage

CLI

You can use the package to transform yUML diagrams to SVG via the Command-Line Interface.

# You can install the package globally (or use npx)
yarn global add yuml2svg

# Prints SVG document on the standard output
yuml2svg < diagram.yuml

# Note: On Windows Powershell, you may need to use cat command instead
cat diagram.yuml | yuml2svg

# Save SVG file to the disk
yuml2svg < diagram.yuml > diagram.svg

# Save SVG file to the disk using dark mode
yuml2svg --dark < diagram.yuml > diagram.svg

Node.JS API

The API exports a function that accepts as arguments:

1. A Readable stream, a Buffer or a string containing the yUML diagram.
2. An optional plain object containing the options for the rendering.
3. An optional plain object containing the options for Viz.js. Check it out if you are using this package in the browser.
4. An optional plain object containing the render options for Viz.js.

The API returns a Promise which resolves in a string containing SVG document as a string.

The options for the rendering are:

• dir: string The direction of the diagram "TB" (default) - topDown, "LR" - leftToRight, "RL" - rightToLeft
• type: string The type of SVG - "class" (default), "usecase", "activity", "state", "deployment", "package", "sequence".
• isDark: boolean Option to get dark or light diagram
• dotHeaderOverrides: object Option to customize output (not supported for sequence diagram)

Please check out Viz.js wiki to get more the documentation of the last two parameters.

Here are some examples of a simple usage you can make of the API:

import fs from "fs";
import yuml2svg from "yuml2svg";

/**
 * Renders a string or a Buffer into SVG with dark mode
 * @param {string | Buffer | Readable} yuml The yUML diagram
 * @returns {Promise<string>} callback The SVG document that represents the yUML diagram
 */
const renderDarkSVG = yuml => yuml2svg(yuml, { isDark: true });

/**
 * Renders a given file into a SVG string asynchronously
 * @param {string} filePath Path to the yUML diagram
 * @returns {Promise<string>} callback The SVG document that represents the yUML diagram
 */
const renderFile = filePath => yuml2svg(fs.createReadStream(filePath));

/**
 * Renders a given file into a SVG string asynchronously
 * @param {string} filePath Path to the yUML diagram
 * @param {{dir:string, type: string, isDark: boolean}} [options]
 * @param {object} [vizOptions] @see https://github.com/mdaines/viz.js/wiki/2.0.0-API
 * @returns {Promise<string>} callback The SVG document that represents the yUML diagram
 */
const renderFileWithOptions = (filePath, options, vizOptions) =>
  yuml2svg(fs.createReadStream(filePath), options, vizOptions);

/**
 * Generates a SVG file from a yUML file
 * @param {string} inputFile Path to the .yuml document to read
 * @param {string} outputFile Path to the .svg file to write
 * @returns {Promise<>} Promise that resolves once the SVG file is written
 */
const generateSVG = async (inputFile, outputFile) => {
  const svg = await yuml2svg(fs.createReadStream(filePath));

  return await fs.promises.writeFile(outputFile, svg);
};

N.B.: yuml2svg is written using ES modules, it means it cannot be required (require('yuml2svg') will throw); although you still can use it from a CJS script using dynamic import:

var fs = require("fs");

/**
 * Renders a given file into a SVG string asynchronously
 * @param {string} filePath Path to the yUML diagram
 * @param {(Error, string)=>any} callback Async callback
 */
function renderFile(filePath, callback) {
  import("yuml2svg")
    .then(function(module) {
      var yuml2svg = module.default;
      return yuml2svg(fs.createReadStream(filePath));
    })

    .then(function(svg) {
      callback(null, svg);
    })
    .catch(callback);
}

Run on the browser

You can find a working example of a browser implementation using webpack here: yuml2svg-playground.

If you want to use streams, pass a ReadableStreamDefaultReader or ReadableStreamBYOBReader object to the API:

import yuml2svg from "https://dev.jspm.io/yuml2svg@5";

const yumlOptions = {};
const vizOptions = {
  workerURL:
    "data:application/javascript,importScripts('https://unpkg.com/viz.js@2.1.2/full.render.js')",
};

fetch("https://raw.githubusercontent.com/aduh95/yuml2svg/master/test/test.yuml")
  .then(response =>
    response.ok
      ? yuml2svg(response.body.getReader(), yumlOptions, vizOptions)
      : Promise.reject(response.text())
  )
  .then(svg =>
    document.body.append(
      new DOMParser().parseFromString(svg, "text/xml").documentElement
    )
  )
  .catch(console.error);

Note: Only UTF-8 is supported when using streams.

Credits

• Thanks to the mdaines's port of Graphviz for JavaScript viz.js.
• Thanks to the jaime-olivares's VSCode extension.