## Notice
This helper is compatible with both Vue 2 (using `@vue/composition-api`) and Vue 3.
## Intro
Extend reactive object returned from composition function
with additional reactive object(such as getters), or additional methods to get these benefits:
- Simplify api of object returned by a composition function.
- Eliminate overhead thinking of whether to use or not to use `value` property of `ref` object to get its value.
## Table of Contents
1. [Installation](#Installation)
2. [Usage](#Usage)
3. [API Reference](#API-Reference)
4. [Motivation](#Motivation)
5. [License](#License)
## Installation
- Using NPM
```bash
npm install vue-extend-reactive
```
- Using Yarn
```bash
yarn add vue-extend-reactive
```
## Usage
```html
Hot Food!
Temperature: {{ hotFood.temperatureInCelcius }} C
Is it cool?: {{ hotFood.isCool ? 'Just cool. Into the mouth!' : 'Nope' }}
```
## API Reference
```ts
export default extend
export declare function extend(object: O, extension: E): O & E
interface Dictionary {
[key: string]: any
}
```
## Motivation
Both reactive and ref have quirk in terms of their syntax. Let's use hot food example above to show it.
### Return reactive object returned as is
```js
import { reactive, computed } from 'vue'
const coolTemperature = 22
export function useHotFood({ temperatureInCelcius }) {
const state = reactive({
temperatureInCelcius,
isHot: computed(() => state.temperatureInCelcius > coolTemperature),
})
function blow() {
state.temperatureInCelcius -= 10
}
// ...
return {
state,
blow,
}
}
```
State would lost reactivity if destructured, so it have to be returned as is.
```js
// Using reactive object named state
const hotFood = useHotFood({ temperatureInCelcius: 100 })
hotfood.state.temperatureInCelcius
hotfood.state.isHot
hotfood.blow()
```
### Return refs
```js
import { ref, computed } from 'vue'
const coolTemperature = 22
export function useHotFood(args) {
const temperatureInCelcius = ref(args.temperatureInCelcius)
const isHot = computed(() => temperatureInCelcius.value > coolTemperature
function blow() {
temperatureInCelcius.value -= 10
}
// ...
return {
temperatureInCelcius,
isHot,
blow,
}
}
```
Ref value have to be accessed through its value property.
Ref may be unwrapped in template,
but it causes syntax inconsistency,
between template and script block.
```js
// Using ref for each prop of state
const hotFood = useHotFood({ temperatureInCelcius: 100 })
hotFood.temperatureInCelcius.value
hotFood.isHot.value
hotFood.blow()
// or
const { temperatureInCelcius, isHot, blow } = useHotFood({ temperatureInCelcius: 100 })
temperatureInCelcius.value
isHot.value
blow()
```
### Enter vue-extend-reactive
To achieve terser syntax, reactive object needs to be extended,
maybe with another reactive object (like getters), or methods.
Reactive object can contain methods when using javascript,
but make it more verbose to call it in same block,
and create error when using typescript.
And thats why `vue-extend-reactive` is created,
to enable reactive object extension leveraging Proxy object,
especially in typescript.
```js
import { reactive, computed } from 'vue'
import { extend } from 'vue-extend-reactive'
const coolTemperature = 22
export function useHotFood({ temperatureInCelcius }) {
const state = reactive({
temperatureInCelcius,
isHot: computed(() => state.temperatureInCelcius > coolTemperature),
})
function blow() {
state.temperatureInCelcius -= 10
}
// ...
return extend(state, { blow })
}
```
Below is the end result after returning extended reactive object.
```js
const hotFood = useHotFood({ temperatureInCelcius: 100 })
hotFood.temperatureInCelcius
hotFood.isHot
hotFood.blow()
```
There is one caveat that returned reactive object cannot be destructured as it will lost reactivity,
but that is a sacrifice I am willing to make, to get terser and more consistent syntax.
## License
[MIT](http://opensource.org/licenses/MIT)
---
_Source: https://npm.io/package/vue-extend-reactive · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._
