microtype

A JavaScript package that implements LaTeX-like text justification, hyphenation, and other micro-typographic adjustments. The name of course is borrowed from the microtype LaTeX package.

Usage

The package can be installed via npm, and imported as an ES module:

npm install microtypejs

import microtype from "microtypejs";

Or loaded directly via a CDN:

<script src="https://unpkg.com/microtypejs/dist/microtype.js"></script>

Once the package is loaded, the most basic usage is just to call the microtype function with an array of elements you want to format.

At present, the elements you want to format must contain nothing but text. Paragraphs containing inline elements are not supported. This is something I want to improve in the future.

microtype({
  elements: document.querySelectorAll("p")
});

More on other configuration options below.

Options

The full list of available options and their defaults are as follows:

type MicrotypeOptions = {
  elements: HTMLElement[];
  maxSpaceShrink: number;
  maxSpaceGrow: number;
  maxTrackingShrink: number;
  maxTrackingGrow: number;
  protrusion: { [key: string]: number };
  hyphenate: boolean;
  showFrame: boolean;
};

const defaultOptions: MicrotypeOptions = {
  elements: [], // The array of elements to format
  maxSpaceShrink: 0.15, // How much space characters can shrink (em)
  maxSpaceGrow: 0.25, // How much space characters can grow (em)
  maxTrackingShrink: 0.01, // How much letter spacing can shrink (em)
  maxTrackingGrow: 0.01, // How much letter spacing can grow (em)
  protrusion: {
    // How much certain characters may protrude from the right margin (em)
    ",": 0.1,
    ".": 0.15,
    "!": 0.1,
    "-": 0.2,
  },
  hyphenate: true, // Whether or not words may hyphenate across lines
  showFrame: false, // Whether or not to show the target frame for formatted elements (for debugging)
};

Demo

TODO