104646d8ca
Summary: Pull Request resolved: https://github.com/facebook/yoga/pull/1285 Enums are currently exposed to the JS package as constants (e.g. `import {ERRATA_NONE} from 'yoga-layout'`). This exports enums in the form of `import {Errata} from 'yoga-layout'` then `Errata.None`. It would be more ergonomic for these to be string union based enums instead, but right now it is a pretty thin wrapper around the native API, we need ordinal values to do things with bit masks, and folks have wanted to serialize them before. Reviewed By: yungsters Differential Revision: D45570417 fbshipit-source-id: dbfd330e939051d0c16460a4d2a996f88f98875c
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.
A specific entrypoint may be specified on platforms which do not understand export conditions.
import {loadYoga} from 'yoga-layout/dist/entrypoint/wasm-async';
Contributing
Requirements
- Emscripten SDK
- CMake >= 3.13
- (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