yoga-layout

What is yoga-layout?

The yoga-layout npm package is a cross-platform layout engine that implements Flexbox. It is designed to be fast and efficient, making it suitable for use in performance-critical applications. Yoga-layout allows developers to create complex layouts with ease, using a simple and intuitive API.

What are yoga-layout's main functionalities?

Basic Flexbox Layout

This code demonstrates how to create a basic Flexbox layout using yoga-layout. It creates a root node with two child nodes, sets their dimensions, and calculates the layout.

const { Node, Yoga } = require('yoga-layout');

const root = Node.create();
root.setWidth(500);
root.setHeight(500);

const child1 = Node.create();
child1.setWidth(100);
child1.setHeight(100);
root.insertChild(child1, 0);

const child2 = Node.create();
child2.setWidth(100);
child2.setHeight(100);
root.insertChild(child2, 1);

root.calculateLayout(Yoga.UNDEFINED, Yoga.UNDEFINED, Yoga.DIRECTION_LTR);

console.log(root.getComputedLayout());
console.log(child1.getComputedLayout());
console.log(child2.getComputedLayout());

Align Items

This code demonstrates how to align items within a container using yoga-layout. The root node is set to align its children to the center.

const { Node, Yoga } = require('yoga-layout');

const root = Node.create();
root.setWidth(500);
root.setHeight(500);
root.setAlignItems(Yoga.ALIGN_CENTER);

const child = Node.create();
child.setWidth(100);
child.setHeight(100);
root.insertChild(child, 0);

root.calculateLayout(Yoga.UNDEFINED, Yoga.UNDEFINED, Yoga.DIRECTION_LTR);

console.log(root.getComputedLayout());
console.log(child.getComputedLayout());

Justify Content

This code demonstrates how to justify content within a container using yoga-layout. The root node is set to justify its children to the center.

const { Node, Yoga } = require('yoga-layout');

const root = Node.create();
root.setWidth(500);
root.setHeight(500);
root.setJustifyContent(Yoga.JUSTIFY_CENTER);

const child = Node.create();
child.setWidth(100);
child.setHeight(100);
root.insertChild(child, 0);

root.calculateLayout(Yoga.UNDEFINED, Yoga.UNDEFINED, Yoga.DIRECTION_LTR);

console.log(root.getComputedLayout());
console.log(child.getComputedLayout());

Other packages similar to yoga-layout

flexbox-layout

The flexbox-layout package provides a similar Flexbox layout engine for JavaScript. It is designed to be easy to use and integrates well with web development frameworks. Compared to yoga-layout, flexbox-layout is more focused on web applications and may not be as performant in cross-platform scenarios.

react-native-flexbox

The react-native-flexbox package is a Flexbox layout engine specifically designed for React Native applications. It provides a similar API to yoga-layout but is tailored for use with React Native components. It is a good alternative for developers working within the React Native ecosystem.

css-layout

The css-layout package is another Flexbox layout engine that implements the CSS Flexbox specification. It is designed to be lightweight and fast, making it suitable for performance-critical applications. Compared to yoga-layout, css-layout is more focused on adhering strictly to the CSS Flexbox specification.

README

yoga-layout

This package provides prebuilt JavaScript bindings for the Yoga layout engine. Both WebAssembly and asm.js variants are packaged, with the optimal loaded based on platform.

Usage

The default entrypoint provides an asynchronous loader function to return a Yoga instance.

import {loadYoga, Align} from 'yoga-layout';

const Yoga = await loadYoga();

const node = Yoga.Node.create();
node.setAlignContent(Align.Center);

An alternative synchronous API is provided for compatibility, but requires using asm.js in browsers instead of WebAssembly, leading to worse performance and larger assets.

import Yoga, {Align} from 'yoga-layout/sync';

const node = Yoga.Node.create();
node.setAlignContent(Align.Center);

Objects created by Yoga.<>.create() are not automatically garbage collected and should be freed once they are no longer in use.

// Free a config
config.free();

// Free a tree of Nodes
node.freeRecursive();

// Free a single Node
node.free();

Selecting WebAssembly or asm.js

For better performance and smaller packages, WebAssembly is preferred to asm.js where available. yoga-layout tries to provide the right default using export maps so that platforms which can take advantage of WebAssembly use it by default.

Different entrypoints are exposed to choose a flavor explicitly.

import {loadYoga} from 'yoga-layout/wasm-async';

Using TypeScript

This package provides out-of-the-box TypeScript typings so long as tsc is configured to support ESM resolution. It is recommended to set moduleResolution: 'bundler' or moduleResolution: node16 in your tsconfig.json according to your environment.

Contributing

Requirements

1. Emscripten SDK
2. CMake >= 3.13
3. (Optional) ninja, for faster builds

Building

git clone https://github.com/facebook/yoga.git
cd yoga/javascript
yarn install
yarn build

Testing

# Build and test all entrypoints
yarn test

# Build and test a specific entrypoint
yarn test:asmjs-sync