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