Scripting with NodeJS

In this guide, we are going to use the meta.json (explained below) file packaged with one of our icon libraries and in the end generates a single html file.


  • Empty Folder named "preview".
  • NodeJS Installed (for npm command line)

The NodeJS command line will allow us to pull down some helper scripts and execute our build.js we'll be writing.

NPM Init

The first step will require you to open a command line of your choice.

  • Run npm init in your /preview folder
  • Press enter a few times to accept all the defaults.
  • Run npm install @mdi/svg @mdi/util (or @mdi/svg-light for Material Design Icons Light)

Awesome, you will now see a folder called node_modules. This contains a copy of the latest version of the SVG's and the meta.json file.

What is meta.json?

The meta.json file is stored in the @mdi/svg package. This contains all the icon information. The data is normalized to cut down on the file size.

[ { "id": "039be9b8-08ad-11e4-bf19-842b2b6cfe1b", "name": "vector-square", "codepoint": "F001", "aliases": [ "mdi" ], "tags": [ "Vector" ], "author": "Austin Andrews", "version": "1.5.54" }, ... ]

Creating the Build Script

The build.js file is below. We'll break down what each part does and what the @mdi/util provides.

const util = require('@mdi/util'); const fileName = "./preview.html"; const version = util.getVersion(); const meta = util.getMeta(true); // withPaths const body = => ` <span onClick="a('${}')" title="${}"> <svg viewBox="0 0 24 24"> <path d="${icon.path}" /> </svg> </span> `).join(''); const template = ` <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Material Design Icons - Preview</title> <style> svg { width: 24px; height: 24px } </style> <script> window.a = x => alert(x); </script> </head> <body> <h1>MDI Preview</h1> ${body} </body> </html> `; util.write(fileName, template); console.log(`\u2714 Build ${version}`);

The @mdi/util includes a few helper methods for working with the @mdi/svg package's data with NodeJS.

  • util.getVersion() Get the semver formatted string of the current @mdi/svg release.
  • util.getMeta(true) Get the meta.json data. Passing true will parse the SVG folder for path data assigning it to .path.
  • util.write(file, data) Write data to a file.
  • Read data from a file.

View the util.js to understand these utilities.

Update package.json

In the package.json a new script needs to be added to handle build.

"scripts": { "test": "echo \"Error: no test specified\" && exit 1", "build": "node build.js" },

To run the build execute npm run build.


Hopefully, you found the above tutorial useful and it allows you to create more complex build scripts.