css-line-break

What is css-line-break?

The css-line-break npm package provides utilities for handling line breaking in text according to the CSS Text Module Level 3 specification. It is useful for developers who need to manage text rendering and line breaking in a way that is consistent with web standards.

What are css-line-break's main functionalities?

Line Break Iterator

This feature allows you to create an iterator that breaks a string into segments according to CSS line breaking rules. The code sample demonstrates how to use the LineBreaker to iterate over the break points in a given text.

const { LineBreaker } = require('css-line-break');
const breaker = LineBreaker('This is a sample text.');
let bk;
while (!(bk = breaker.next()).done) {
  console.log(bk.value);
}

Line Break Opportunities

This feature allows you to collect all possible line break opportunities in a string. The code sample shows how to gather all break points into an array.

const { LineBreaker } = require('css-line-break');
const breaker = LineBreaker('This is a sample text.');
const breakPoints = [];
let bk;
while (!(bk = breaker.next()).done) {
  breakPoints.push(bk.value);
}
console.log(breakPoints);

Custom Line Break Rules

This feature allows you to apply custom line break rules, such as 'strict' or 'normal'. The code sample demonstrates how to use the 'strict' line break rule.

const { LineBreaker } = require('css-line-break');
const breaker = LineBreaker('This is a sample text.', { lineBreak: 'strict' });
let bk;
while (!(bk = breaker.next()).done) {
  console.log(bk.value);
}

Other packages similar to css-line-break

linebreak

The linebreak package provides Unicode line breaking algorithms. It is similar to css-line-break but focuses more on Unicode standards rather than CSS-specific rules.

wordwrapjs

The wordwrapjs package offers text wrapping and line breaking functionalities. It is more general-purpose compared to css-line-break, which is specifically tailored to CSS Text Module Level 3 specifications.

README

css-line-break

A JavaScript library for Line Breaking and identifying Word Boundaries, implementing the Unicode Line Breaking Algorithm (UAX #14)

Line breaking, also known as word wrapping, is the process of breaking a section of text into lines such that it will fit in the available width of a page, window or other display area. The Unicode Line Breaking Algorithm performs part of this process. Given an input text, it produces a set of positions called "break opportunities" that are appropriate points to begin a new line. The selection of actual line break positions from the set of break opportunities is not covered by the Unicode Line Breaking Algorithm, but is in the domain of higher level software with knowledge of the available width and the display size of the text.

In addition, the module implements CSS specific tailoring options to line breaking as defined in CSS Text Module Level 3.

Installing

You can install the module via npm:

npm install css-line-break

Usage

The LineBreaker creates an iterator that returns Breaks for a given text.

LineBreaker(text, [options]);

Example

JSFiddle

import {LineBreaker} from 'css-line-break';

const breaker = LineBreaker('Lorem ipsum lol.', {
    lineBreak: 'strict',
    wordBreak: 'normal'
});

const words = [];
let bk;

while (!(bk = breaker.next()).done) {
    words.push(bk.value.slice());
}

assert.deepEqual(words, ['Lorem ', 'ipsum ', 'lol.']);

Options

The following parameters are available for the options:

• lineBreak: normal | strict
• wordBreak: normal | break-all | break-word | keep-all

For more information how they affect the line breaking algorithms, check out CSS Text Module Level 3.

Testing

You can run the test suite with:

npm test

The library implements all the LineBreakTest.txt tests and a number of CSS web-platform-tests.

Changelog

2.1.0 (2022-01-22)

feat

• update to use utrie dep (#20) (18adab4), closes #20

fix

• source maps (#19) (60cdede), closes #19