e60ae290ea
Summary: Yoga has a known bug where marginStart and marginEnd will swap with row-reverse flex direction. This is not the intended behavior. On Paper this is also an issue with marginLeft and marginRight (at least we think Paper is the culprit, not exactly clear yet). margin-start (and end) is not actually valid css. The gentest.rb script will just turn this into margin-left, but the cpp generated will properly test marginStart. This seems a bit weird to be since marginStart != marginLeft AFAIK. Things like RTL and LTR modes might make this test not exactly right. But given how many other tests depend on this quirk I think it is fine to add as is - the end result is the same after all. If not, a followup would be to add support for mapping margin-inline-start (valid css) to marginStart. Anyway, this diff is to add test coverage for this scenario. Next stop is to actually try to fix this problem, which may be a bit harder :P See https://github.com/facebook/yoga/issues/1208 for more info. Reviewed By: NickGerleman Differential Revision: D49744271 fbshipit-source-id: 75b8dd0cc5c53b2f338476fb70b60006aaa89054
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
- 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