2ea4c043fd
Summary: I am about to embark on supporting `position: static` in Yoga. The enum exists already (and is the default position type, lol) but does not actually do anything and just behaves like `position: relative`. My approach here is to write a bunch of tests to test for the various behaviors of static positions and then develop on Yoga afterwards to get those tests passing. To do this, we need to make a few changes to the gentest files as there is not support for adding `position: static` at the moment: * Make it so that the gentest code can physically write `YGPositionTypeStatic` if it encounters `position: static` in the style * Make it so that gentest.js knows that Yoga's default is actually static. This way the code generated in the tests will actually label nodes for non default values * Explicitly label the position type even when it is not declared in the style prop (with the exception of the default) * Regenerate all the tests Additionally I added the first, basic test: making sure insets do nothing on a statically positioned element. Reviewed By: NickGerleman Differential Revision: D50437855 fbshipit-source-id: 0e8bbf1c224d477ea4592b7563d0b70d2ffa79c8
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