88 lines
1.7 KiB
Markdown
88 lines
1.7 KiB
Markdown
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# babel-plugin-transform-class-properties
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> This plugin transforms es2015 static class properties as well as properties declared with the es2016 property initializer syntax.
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## Example
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Below is a class with four class properties which will be transformed.
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```js
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class Bork {
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//Property initializer syntax
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instanceProperty = "bork";
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boundFunction = () => {
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return this.instanceProperty;
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}
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//Static class properties
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static staticProperty = "babelIsCool";
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static staticFunction = function() {
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return Bork.staticProperty;
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}
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}
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let myBork = new Bork;
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//Property initializers are not on the prototype.
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console.log(myBork.prototype.boundFunction); // > undefined
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//Bound functions are bound to the class instance.
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console.log(myBork.boundFunction.call(undefined)); // > "bork"
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//Static function exists on the class.
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console.log(Bork.staticFunction()); // > "babelIsCool"
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```
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## Installation
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```sh
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npm install --save-dev babel-plugin-transform-class-properties
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```
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## Usage
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### Via `.babelrc` (Recommended)
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**.babelrc**
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```json
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// without options
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{
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"plugins": ["transform-class-properties"]
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}
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// with options
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{
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"plugins": [
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["transform-class-properties", { "spec": true }]
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]
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}
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```
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### Via CLI
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```sh
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babel --plugins transform-class-properties script.js
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```
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### Via Node API
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```javascript
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require("babel-core").transform("code", {
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plugins: ["transform-class-properties"]
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});
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```
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## Options
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### `spec`
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`boolean`, defaults to `false`.
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Class properties are compiled to use `Object.defineProperty`. Static fields are now defined even if they are not initialized.
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## References
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* [Proposal: ES Class Fields & Static Properties](https://github.com/jeffmo/es-class-static-properties-and-fields)
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