https://github.com/thoov/ember-weakmap

Ember.WeakMap Polyfill Addon
https://github.com/thoov/ember-weakmap

ember-addon ember-weakmap emberjs polyfill weakmap

Last synced: 19 days ago
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Ember.WeakMap Polyfill Addon

• Host: GitHub
• URL: https://github.com/thoov/ember-weakmap
• Owner: thoov
• License: mit
• Created: 2015-09-15T20:21:32.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2022-12-08T18:18:01.000Z (almost 2 years ago)
• Last Synced: 2024-10-19T17:57:48.539Z (about 1 month ago)
• Topics: ember-addon, ember-weakmap, emberjs, polyfill, weakmap
• Language: JavaScript
• Homepage: https://github.com/emberjs/rfcs/blob/master/text/0091-weakmap.md
• Size: 1.07 MB
• Stars: 8
• Watchers: 2
• Forks: 7
• Open Issues: 18
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
# Ember WeakMap

This addon is a polyfill for the [Ember.WeakMap RFC](https://github.com/emberjs/rfcs/blob/master/text/0091-weakmap.md).

A WeakMap provides a mechanism for storing and retrieving private state. The WeakMap

itself does not retain a reference to the state, allowing the state to be reclaimed

when the key is reclaimed.

A traditional WeakMap (and the one that will be part of the ES2015 language) allows for

weakness from key -> map, and also from map -> key. This allows either the Map,

or the key being reclaimed to also release the state.

Unfortunately, this bi-directional weakness is problematic to polyfill.

Luckily, uni-directional weakness, in either direction, "just works". A polyfill

must just choose a direction.

Note: Just like ES2015 WeakMap, only non null Objects can be used as keys

## Installation

```shell

ember install ember-weakmap

```

## Usage

```js

import Ember from 'ember';

const myWeakMap = new Ember.WeakMap();

```

### Set

```js

/*

 * @method set

 * @param key {Object}

 * @param value {Any}

 * @return {Any} stored value

 */

 

const emailObj = { id: 1, subject: 'Hello World' };

myWeakMap.set(emailObj, {read: true});

```

The key **must be an object**.

### Get

```js

/*

 * @method get

 * @param key {Object}

 * @return {*} stored value

*/

myWeakMap.get(emailObj); // => { read: true }

myWeakMap.get(someObjThatWasNotSet); // => undefined

```

### Has

```js

/*

 * @method has

 * @param key {Object}

 * @return {Boolean} if the key exists

*/

myWeakMap.has(emailObj); // => true

myWeakMap.has(someObjThatWasNotSet); // => false

```

### Delete

```js

/*

 * @method delete

 * @param key {Object}

 */

myWeakMap.delete(emailObj);

myWeakMap.get(emailObj); // => undefined

myWeakMap.has(emailObj); // false

```