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
77 lines
1.8 KiB
Markdown
77 lines
1.8 KiB
Markdown
# yoga-layout
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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.
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## Usage
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The default entrypoint provides an asynchronous loader function to return a Yoga instance.
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```ts
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import {loadYoga, Align} from 'yoga-layout';
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const Yoga = await loadYoga();
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const node = Yoga.Node.create();
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node.setAlignContent(Align.Center);
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```
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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.
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```ts
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import Yoga, {Align} from 'yoga-layout/sync';
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const node = Yoga.Node.create();
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node.setAlignContent(Align.Center);
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```
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Objects created by `Yoga.<>.create()` are not automatically garbage collected and should be freed once they are no longer in use.
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```ts
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// Free a config
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config.free();
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// Free a tree of Nodes
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node.freeRecursive();
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// Free a single Node
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node.free();
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```
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## Selecting WebAssembly or asm.js
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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](https://webpack.js.org/guides/package-exports/#conditional-syntax) so that platforms which can take advantage of WebAssembly use it by default.
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A specific entrypoint may be specified on platforms which do not understand export conditions.
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```ts
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import {loadYoga} from 'yoga-layout/dist/entrypoint/wasm-async';
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```
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## Contributing
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### Requirements
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1. Emscripten SDK
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1. CMake >= 3.13
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1. (Optional) ninja, for faster builds
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### Building
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```bash
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git clone https://github.com/facebook/yoga.git
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cd yoga/javascript
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yarn install
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yarn build
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```
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### Testing
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```bash
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# Build and test all entrypoints
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yarn test
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# Build and test a specific entrypoint
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yarn test:asmjs-sync
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```
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