Vue Demi (half in French) is a developing utility
allows you to write Universal Vue Libraries for Vue 2 & 3
See more details in this blog post
## Strategies
- `<=2.6`: exports from `vue` + `@vue/composition-api` with plugin auto installing.
- `2.7`: exports from `vue` (Composition API is built-in in Vue 2.7).
- `>=3.0`: exports from `vue`, with polyfill of Vue 2's `set` and `del` API.
## Usage
Install this as your plugin's dependency:
```bash
npm i vue-demi
# or
yarn add vue-demi
# or
pnpm i vue-demi
```
Add `vue` and `@vue/composition-api` to your plugin's peer dependencies to specify what versions you support.
```jsonc
{
"dependencies": {
"vue-demi": "latest"
},
"peerDependencies": {
"@vue/composition-api": "^1.0.0-rc.1",
"vue": "^2.0.0 || >=3.0.0"
},
"peerDependenciesMeta": {
"@vue/composition-api": {
"optional": true
}
},
"devDependencies": {
"vue": "^3.0.0" // or "^2.6.0" base on your preferred working environment
},
}
```
Import everything related to Vue from it, it will redirect to `vue@2` + `@vue/composition-api` or `vue@3` based on users' environments.
```ts
import { ref, reactive, defineComponent } from 'vue-demi'
```
Publish your plugin and all is done!
> When using with [Vite](https://vitejs.dev), you will need to opt-out the pre-bundling to get `vue-demi` work properly by
> ```js
> // vite.config.js
> export default defineConfig({
> optimizeDeps: {
> exclude: ['vue-demi']
> }
> })
> ```
### Extra APIs
`Vue Demi` provides extra APIs to help distinguish users' environments and to do some version-specific logic.
### `isVue2` `isVue3`
```ts
import { isVue2, isVue3 } from 'vue-demi'
if (isVue2) {
// Vue 2 only
} else {
// Vue 3 only
}
```
### `Vue2`
To avoid bringing in all the tree-shakable modules, we provide a `Vue2` export to support access to Vue 2's global API. (See [#41](https://github.com/vueuse/vue-demi/issues/41).)
```ts
import { Vue2 } from 'vue-demi'
if (Vue2) {
Vue2.config.ignoredElements.push('x-foo')
}
```
### `install()`
Composition API in Vue 2 is provided as a plugin and needs to be installed on the Vue instance before using. Normally, `vue-demi` will try to install it automatically. For some usages where you might need to ensure the plugin gets installed correctly, the `install()` API is exposed to as a safe version of `Vue.use(CompositionAPI)`. `install()` in the Vue 3 environment will be an empty function (no-op).
```ts
import { install } from 'vue-demi'
install()
```
## CLI
### Manually Switch Versions
To explicitly switch the redirecting version, you can use these commands in your project's root.
```bash
npx vue-demi-switch 2
# or
npx vue-demi-switch 3
```
### Package Aliasing
If you would like to import `vue` under an alias, you can use the following command
```bash
npx vue-demi-switch 2 vue2
# or
npx vue-demi-switch 3 vue3
```
Then `vue-demi` will redirect APIs from the alias name you specified, for example:
```ts
import * as Vue from 'vue3'
var isVue2 = false
var isVue3 = true
var Vue2 = undefined
export * from 'vue3'
export {
Vue,
Vue2,
isVue2,
isVue3,
}
```
### Auto Fix
If the `postinstall` hook doesn't get triggered or you have updated the Vue version, try to run the following command to resolve the redirecting.
```bash
npx vue-demi-fix
```
### Isomorphic Testings
You can support testing for both versions by adding npm alias in your dev dependencies. For example:
```json
{
"scripts": {
"test:2": "vue-demi-switch 2 vue2 && jest",
"test:3": "vue-demi-switch 3 && jest",
},
"devDependencies": {
"vue": "^3.0.0",
"vue2": "npm:vue@2"
},
}
```
or
```json
{
"scripts": {
"test:2": "vue-demi-switch 2 && jest",
"test:3": "vue-demi-switch 3 vue3 && jest",
},
"devDependencies": {
"vue": "^2.6.0",
"vue3": "npm:vue@3"
},
}
```
## Examples
See [examples](./examples).
## Who is using this?
- [VueUse](https://github.com/vueuse/vueuse) - Collection of Composition API utils
- [@vue/apollo-composable](https://github.com/vuejs/vue-apollo/tree/v4/packages/vue-apollo-composable) - Apollo GraphQL functions for Vue Composition API
- [vuelidate](https://github.com/vuelidate/vuelidate) - Simple, lightweight model-based validation
- [vue-composition-test-utils](https://github.com/ariesjia/vue-composition-test-utils) - Simple vue composition api unit test utilities
- [vue-use-stripe](https://github.com/frandiox/vue-use-stripe) - Stripe Elements wrapper for Vue.js
- [@opd/g2plot-vue](https://github.com/open-data-plan/g2plot-vue) - G2plot for vue
- [vue-echarts](https://github.com/ecomfe/vue-echarts) - Vue.js component for Apache ECharts.
- [fluent-vue](https://github.com/Demivan/fluent-vue) - Vue.js integration for [Fluent.js](https://github.com/projectfluent/fluent.js) - JavaScript implementation of [Project Fluent](https://projectfluent.org)
- [vue-datatable-url-sync](https://github.com/socotecio/vue-datatable-url-sync) - Synchronize datatable options and filters with the url to keep user preference even after refresh or navigation
- [vue-insta-stories](https://github.com/UnevenSoftware/vue-insta-stories) - Instagram stories in your vue projects.
- [vue-tiny-validate](https://github.com/FrontLabsOfficial/vue-tiny-validate) - Tiny Vue Validate Composition
- [v-perfect-signature](https://github.com/wobsoriano/v-perfect-signature) - Pressure-sensitive signature drawing for Vue 2 and 3
- [vue-winbox](https://github.com/wobsoriano/vue-winbox) - A wrapper component for WinBox.js that adds the ability to mount Vue components.
- [vue-word-highlighter](https://github.com/kawamataryo/vue-word-highlighter) - The word highlighter library for Vue 2 and Vue 3
- [vue-chart-3](https://github.com/victorgarciaesgi/vue-chart-3) - Vue.js component for Chart.js
- [json-editor-vue](https://github.com/cloydlau/json-editor-vue) - JSON editor & viewer for Vue 2 and 3.
- [kidar-echarts](https://github.com/kidarjs/kidar-echarts) - A simpler echarts component for Vue 2 and 3.
- [vue3-sketch-ruler](https://github.com/kakajun/vue3-sketch-ruler) - The zoom operation used for page presentation for Vue 2 and 3( Replace render function with template )
- [vue-rough-notation](https://github.com/Leecason/vue-rough-notation) - RoughNotation wrapper component for Vue 2 and 3.
- [vue-request](https://github.com/AttoJS/vue-request) - Vue composition API for data fetching, supports SWR, polling, error retry, cache request, pagination, etc.
- [vue3-lazyload](https://github.com/murongg/vue3-lazyload) - A vue3.x image lazyload plugin.
- [vue-codemirror6](https://github.com/logue/vue-codemirror6) - CodeMirror6 component for Vue2 and 3.
- [@tanstack/vue-query](https://github.com/TanStack/query) - TanStack Query for Vue.
> open a PR to add your library ;)
## Underhood
See [the blog post](https://antfu.me/posts/make-libraries-working-with-vue-2-and-3/#-introducing-vue-demi).
## License
MIT License © 2020 [Anthony Fu](https://github.com/antfu)