https://github.com/trakkasure/babel-plugin-transform-private-properties

Provides private properties by using WeakMap
https://github.com/trakkasure/babel-plugin-transform-private-properties

Last synced: 3 months ago
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Provides private properties by using WeakMap

• Host: GitHub
• URL: https://github.com/trakkasure/babel-plugin-transform-private-properties
• Owner: Trakkasure
• Created: 2016-07-18T01:22:28.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2016-08-21T18:47:44.000Z (over 8 years ago)
• Last Synced: 2024-10-11T23:04:14.233Z (3 months ago)
• Language: JavaScript
• Size: 19.5 KB
• Stars: 4
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# babel-plugin-transform-private-properties

Compile private variables into classes utilizing weak maps.

## Installation

```sh

$ npm install babel-plugin-transform-private-properties

```

## Usage

### Via `.babelrc` (Recommended)

**.babelrc**

```json

{

  "plugins": ["babel-plugin-transform-private-properties"]

}

```

### Via CLI

```sh

$ babel --plugins babel-plugin-transform-private-properties script.js

```

### Via Node API

```javascript

require("babel-core").transform("code", {

  plugins: ["babel-plugin-transform-private-properties"]

});

```

## Implementation

```javascript

class TestClass {

    @Private

    p=1; // Decalare private var. Very important, @Private is on it's own line, and is capitalized.

    @Private

    s;

    // Declare non-private class property.

    j=2;

    constructor() {

        this.p = 2; // Setting private.

        var self = this // Yes, we follow copying this scope.

          , other="gone";

        self.p = this.p.g; // Setting private (p) self is assigned to "this" so assign p to value of p.g

        this.func1("constructor",this.p); // Call func1 (which is private) with options. Can't call fun1 outside of this class.

 

        var me;

        me = self; // Yes, we follow copying this scope too.

        me.s = 5;

        me.p = 7;

        me.j = 8;

        self = me;

        self.p = me.p;

    }

    // You can create public functions with same name as private variable as a way to access the private in a controlled way.

    p() {

        return this.p;

    }

    // Getters can be the same as a private variable to gate-keep access.

    get s { // this probably shouldn't be allowed to work.

	    return this.s;

    }

    @Private

    func1(fromWhere) {

        console.log("This is the first function called from ",fromWhere);

    }

}

```

This results in the usage such as: 

```javascript

var t = new TestClass();

t.func1("Outside"); // t.func1 is not a function

t.s = "hi" // TypeError: Cannot set property s of # which has only a getter

console.log(t.s); //outputs "5"

console.log(t.p()) // outputs "7"

```