d-path-parser

JavaScript parser for SVG <path>'s d attribute.

Reason

The syntax for the d attribute is compact and expressive, but unfortunately it's also dramatic to debug/maintain/read. This parser gives you a breakdown of the commands in the string, ready for you to read and manipulate.

There's another library with the same purpose around, maintained by Hugh Kennedy. Its main feature is that's generated from a formal grammar, so that's actually pretty neat. On the down size, there's its... size, and the fact that it's quite slow compared to this one. We're talking about 11x the size minified, 3.5 the size minified and gzipped (d-path-parser is less than 1K), and 6x-10x slower depending on the input (the longer, the slower) and the environment.

One may argue that size and speed aren't usually important features, and they might be right. d-path-parser also has 100% test coverage, by the way.

Installation

Via npm/yarn:

npm install d-path-parser
yarn add d-path-parser

Via bower;

bower install d-path-parser

Usage

As a CommonJS package:

const parse = require("d-path-parser");
const path = "M0,0 l10,10 A14.142 14.142 0 1 1 10,-10 Z";
const commands = parse(path);

This will yield the following result:

[{
    code: "M",
    relative: false,
    end: { x: 0, y: 0 }
}, {
    code: "l",
    relative: true,
    end: { x: 10, y: 10 }
}, {
    code: "A",
    relative: false,
    radii: { x: 14.142, y: 14.142 },
    rotation: 0,
    large: true,
    clockwise: true,
    end: { x: 10, y: -10 }
}, {
    code: "Z"
}]

The parser can also be loaded via AMD (define([ "d-path-parser", ... ], function(parse) { ... })) and, if no module loader is detected, a global function dPathParse will be defined.

Gotchas

d-path-parser does not assume the given string is the full path string of a d attribute. In short, it won't throw if the first command is not a moveTo.

Tests

Mocha and Chai are used for tests. Just run npm test (or mocha if it's globally installed).

License

MIT @ Massimo Artizzu 2016. See LICENSE.