# ember-weakmap

> ES2015 WeakMap polyfill for Ember.WeakMap

Latest version **3.3.2** (published 2019-02-21) · MIT license · 0 weekly downloads

## Install

```sh
npm install ember-weakmap
pnpm add ember-weakmap
yarn add ember-weakmap
bun add ember-weakmap
```

## Health

**Score 15/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 3.3.2 |
| Published | 2019-02-21 |
| First published | 2015-09-16 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | CommonJS |
| Node | 6.* \|\| 8.* \|\| >= 10.* |
| Dependencies | 3 |
| Unpacked size | 9.6 KB |
| Known vulnerabilities | 0 (+2 in 1 direct dependencies) |
| Install scripts | no |
| GitHub stars | 8 |
| Author | Travis Hoover |
| Maintainers | thoov |
| Keywords | polyfill, weakmap, ember, emberjs, ember-addon |

## Links

- npm: https://www.npmjs.com/package/ember-weakmap
- Repository: https://github.com/thoov/ember-weakmap
- Homepage: https://github.com/thoov/ember-weakmap#readme
- Issues: https://github.com/thoov/ember-weakmap/issues
- npm.io page: https://npm.io/package/ember-weakmap

## Dependencies (3)

- [debug](https://npm.io/package/debug.md) ^3.1.0
- [browserslist](https://npm.io/package/browserslist.md) ^3.1.1
- [ember-cli-babel](https://npm.io/package/ember-cli-babel.md) ^6.6.0

## Recent versions

- 3.3.2 (latest) — 2019-02-21
- 3.3.1 — 2018-08-24
- 3.3.0 — 2018-07-26
- 3.2.0 — 2018-04-09
- 3.1.1 — 2017-10-26
- 3.1.0 — 2017-10-24
- 3.0.1 — 2017-10-19
- 3.0.0 — 2017-08-10
- 2.0.0 — 2016-06-21
- 1.1.0 — 2016-04-23
- 1.0.0 — 2016-03-07
- 0.4.0 — 2015-09-18
- 0.3.0 — 2015-09-17
- 0.2.0 — 2015-09-17
- 0.1.0 — 2015-09-16

## 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
```

---
_Source: https://npm.io/package/ember-weakmap · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._