lottie-web-parser

Utility functions for parsing color & text information from lottie-web JSONs.

Motivation

lottie-web is a great way of rendering After Effects animations natively on the Web. These animations are exported from After Effects as JSON files that hold all animation data: layers, shapes, colors, keyframes etc.

At Flixier we wanted to build an editor for these lottie animations, so you can customize yours as you please. Demo below:

The hardest part was understanding the JSON format and parsing/modifying it in such a way that

1. it's still valid
2. it produces the result we want.

Features

• determine if the lottie has text information or not
• find and replace all shape colors (fill or stroke), including those that have the color specified as an JavaScript expression
• parse texts

Installation

$ npm install lottie-web-parser

Then, import this package into your app (you might need a build tool like webpack if wanting to run in the browser.

API

hasTextLayers(animaitonData): boolean

Checks if the animation data passed as argument has text information or not.

import LottieWebParser from 'lottie-web-parser';
import animationData from './data.js';

LottieWebParser.hasTextLayers();

parseColors(animationData): Array<{ name: string, path: string, color: number[] }>

Parses the animationData and returns an array of color information, including the name of the shape/layer.

import LottieWebParser from 'lottie-web-parser';
import animationData from './data.js';

let colorInfo = LottieWebParser.parseColors(animationData);
console.log(colorInfo);

replaceColor(rgba, path, animationData)

Params:

• rgba: Array
• path: string
• animationData: JSON object

Modifies the animationData in place, by replacing the color value found at that path after it adjusts the values:

• if the current color values are in [0-1] then it will normalize to this interval
• otherwise it will use the real values

import LottieWebParser from 'lottie-web-parser';
import animationData from './data.js';

let colorInfo = LottieWebParser.parseColors(animationData);
LottieWebParser.replaceColor([255, 0, 0, 1], colorInfo[0].path, animationData);

replaceKeyframeColor(rgba, path, animationData)

Params:

• rgba: Array
• path: string
• animationData: JSON object

Modifies the animation data in place, by replacing the value found at that path. Similar to replaceColor above, it adjusts the values.

import LottieWebParser from 'lottie-web-parser';
import animationData from './data.js';

let path = 'layers.5.shapes.2.c.k.0';
LottieWebParser.replaceColor([255, 0, 0, 1], path, animationData);

getKeyframeColors(path, animationData)

Params:

• path: string
• animationData: JSON object

Returns the color values at path. If the values are in [0, 1] interval it will adjust them to the RGB interval [0-255].

parseTexts(animationData) : Array<{name: string, text: string, fontFamily: string, fontName: string, path: string}>

Parses the animationData and returns an array of text information.

import LottieWebParser from 'lottie-web-parser';
import animationData from './data.js';

if (LottieWebParser.hasTextLayers(animationData)) {
    let textInfo = LottieWebParser.parseTexts(animationData);
    console.log(textInfo);
}

// Example response
[{
    name: 't1',
    text: 'Type something here',
    fontName: 'Roboto-Black',
    fontFamily: 'Roboto',
    path: `layers.2.t.d.k.0.s.t`
}]

PS: special thanks to sonaye/lottie-editor, whose code was the foundation of this package.