8c3e01166b
Summary: Pull Request resolved: https://github.com/facebook/yoga/pull/1547 X-link: https://github.com/facebook/react-native/pull/42251 Yoga has an odd behavior, where `start`/`end` edges under row-reverse are relative to flex-direction, instead of writing direction. While Yoga doesn't actually document what this behavior is supposed to be, it goes against CK documentation, historic RN documentation, and the behavior valid on the web. It is also applied inconsistently (e.g. sometimes only on container, sometimes on child). It really is a bug, instead of an intended behavior. We changed the default behavior for Yoga, but left the existing one behind an errata (so existing fbsource users got old behavior). We have previously seen this behavior show up in product code, including CK when running on FlexLayout. `row-reverse` is surprisingly uncommon though: 1. Litho has <40 usages 2. RN has ~40 usages in `RKJSModules`,~30 in `arvr/js`, ~6 in `xplat/archon` 3. CK has ~80 usages 4. NT has ~40 usages There are few enough, mostly simple components, that we can inspect through each of them, looking for signs they will hit the issue (at the potential chance of missing some). CK accounts for 10/14 usages that I could tell would trigger the issue, since it only exposes start/end edge, and not left/right. It might make sense to make it preserve behavior instead, to reduce risk a bit. FlexLayout is now separately powering Bloks, which wasn't surveyed, so I didn't touch CK behavior under Bloks. There could also be other usages in other frameworks/bespoke usages, and this has implications for OSS users. But based on our own usage, of many, many components, this seems rare. Changelog: [General][Breaking] - Make `start/end` in styles always refer to writing direction Reviewed By: pentiumao, joevilches Differential Revision: D52698130 fbshipit-source-id: 2a9ac47e177469f30dc988d916b6c0ad95d53461
yoga-layout
This package provides prebuilt WebAssembly bindings for the Yoga layout engine.
Usage
import {Yoga, Align} from 'yoga-layout';
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();
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.
ES Modules
yoga-layout is only provided as an ES Module, relying on top-level await. This allows providing a synchronous API, while still allowing async WebAssembly compilation in browsers, and will allow eventual usage of ESM/WASM interop.
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