forked from zhurui/management
185 lines
4.5 KiB
Markdown
185 lines
4.5 KiB
Markdown
|
## @vue/babel-plugin-transform-vue-jsx
|
||
|
|
||
|
> Babel plugin for Vue 2.0 JSX
|
||
|
|
||
|
### Babel Compatibility Notes
|
||
|
|
||
|
- This repo is only compatible with Babel 7.x, for 6.x please use [vuejs/babel-plugin-transform-vue-jsx](https://github.com/vuejs/babel-plugin-transform-vue-jsx)
|
||
|
|
||
|
### Requirements
|
||
|
|
||
|
- Assumes you are using Babel with a module bundler e.g. Webpack, because the spread merge helper is imported as a module to avoid duplication.
|
||
|
|
||
|
- This is mutually exclusive with `babel-plugin-transform-react-jsx`.
|
||
|
|
||
|
### Usage
|
||
|
|
||
|
```bash
|
||
|
npm install @vue/babel-plugin-transform-vue-jsx --save-dev
|
||
|
npm install @vue/babel-helper-vue-jsx-merge-props --save
|
||
|
```
|
||
|
|
||
|
In your `.babelrc`:
|
||
|
|
||
|
```json
|
||
|
{
|
||
|
"plugins": ["transform-vue-jsx"]
|
||
|
}
|
||
|
```
|
||
|
|
||
|
However it is recommended to use the [configurable preset](../babel-preset-jsx/README.md) instead.
|
||
|
|
||
|
### Details
|
||
|
|
||
|
The plugin transpiles the following JSX:
|
||
|
|
||
|
```jsx
|
||
|
<div id="foo">{this.text}</div>
|
||
|
```
|
||
|
|
||
|
To the following JavaScript:
|
||
|
|
||
|
```js
|
||
|
h(
|
||
|
'div',
|
||
|
{
|
||
|
attrs: {
|
||
|
id: 'foo',
|
||
|
},
|
||
|
},
|
||
|
[this.text],
|
||
|
)
|
||
|
```
|
||
|
|
||
|
Note the `h` function, which is a shorthand for a Vue instance's `$createElement` method, must be in the scope where the JSX is. Since this method is passed to component render functions as the first argument, in most cases you'd do this:
|
||
|
|
||
|
```js
|
||
|
Vue.component('jsx-example', {
|
||
|
render(h) {
|
||
|
// <-- h must be in scope
|
||
|
return <div id="foo">bar</div>
|
||
|
},
|
||
|
})
|
||
|
```
|
||
|
|
||
|
### Difference from React JSX
|
||
|
|
||
|
First, Vue 2.0's vnode format is different from React's. The second argument to the `createElement` call is a "data object" that accepts nested objects. Each nested object will be then processed by corresponding modules:
|
||
|
|
||
|
```js
|
||
|
render (h) {
|
||
|
return h('div', {
|
||
|
// Component props
|
||
|
props: {
|
||
|
msg: 'hi'
|
||
|
},
|
||
|
// Normal HTML attributes
|
||
|
attrs: {
|
||
|
id: 'foo'
|
||
|
},
|
||
|
// DOM props
|
||
|
domProps: {
|
||
|
innerHTML: 'bar'
|
||
|
},
|
||
|
// Event handlers are nested under "on", though
|
||
|
// modifiers such as in v-on:keyup.enter are not
|
||
|
// supported. You'll have to manually check the
|
||
|
// keyCode in the handler instead.
|
||
|
on: {
|
||
|
click: this.clickHandler
|
||
|
},
|
||
|
// For components only. Allows you to listen to
|
||
|
// native events, rather than events emitted from
|
||
|
// the component using vm.$emit.
|
||
|
nativeOn: {
|
||
|
click: this.nativeClickHandler
|
||
|
},
|
||
|
// Class is a special module, same API as `v-bind:class`
|
||
|
class: {
|
||
|
foo: true,
|
||
|
bar: false
|
||
|
},
|
||
|
// Style is also same as `v-bind:style`
|
||
|
style: {
|
||
|
color: 'red',
|
||
|
fontSize: '14px'
|
||
|
},
|
||
|
// Other special top-level properties
|
||
|
key: 'key',
|
||
|
ref: 'ref',
|
||
|
// Assign the `ref` is used on elements/components with v-for
|
||
|
refInFor: true,
|
||
|
slot: 'slot'
|
||
|
})
|
||
|
}
|
||
|
```
|
||
|
|
||
|
The equivalent of the above in Vue 2.0 JSX is:
|
||
|
|
||
|
```jsx
|
||
|
render (h) {
|
||
|
return (
|
||
|
<div
|
||
|
// Component props
|
||
|
propsMsg="hi"
|
||
|
// Normal attributes or component props.
|
||
|
id="foo"
|
||
|
// DOM properties are prefixed with `domProps`
|
||
|
domPropsInnerHTML="bar"
|
||
|
// event listeners are prefixed with `on` or `nativeOn`
|
||
|
onClick={this.clickHandler}
|
||
|
nativeOnClick={this.nativeClickHandler}
|
||
|
// other special top-level properties
|
||
|
class={{ foo: true, bar: false }}
|
||
|
style={{ color: 'red', fontSize: '14px' }}
|
||
|
key="key"
|
||
|
ref="ref"
|
||
|
// assign the `ref` is used on elements/components with v-for
|
||
|
refInFor
|
||
|
slot="slot">
|
||
|
</div>
|
||
|
)
|
||
|
}
|
||
|
```
|
||
|
|
||
|
### Component Tip
|
||
|
|
||
|
If a custom element starts with lowercase, it will be treated as a string id and used to lookup a registered component. If it starts with uppercase, it will be treated as an identifier, which allows you to do:
|
||
|
|
||
|
```js
|
||
|
import Todo from './Todo.js'
|
||
|
|
||
|
export default {
|
||
|
render(h) {
|
||
|
return <Todo /> // no need to register Todo via components option
|
||
|
},
|
||
|
}
|
||
|
```
|
||
|
|
||
|
### JSX Spread
|
||
|
|
||
|
JSX spread is supported, and this plugin will intelligently merge nested data properties. For example:
|
||
|
|
||
|
```jsx
|
||
|
const data = {
|
||
|
class: ['b', 'c'],
|
||
|
}
|
||
|
const vnode = <div class="a" {...data} />
|
||
|
```
|
||
|
|
||
|
The merged data will be:
|
||
|
|
||
|
```js
|
||
|
{ class: ['a', 'b', 'c'] }
|
||
|
```
|
||
|
|
||
|
### Vue directives
|
||
|
|
||
|
Vue directives are usable the same way as in template with a few key differences:
|
||
|
|
||
|
1. You can use directives camelCased instead of kebab-cased (vMyDirective is treated as `v-my-directive`)
|
||
|
2. You have to use underscore sign instead of dots for modifiers because of JSXIdentifier limitation.
|
||
|
3. Only runtime directives work (only v-show and custom directives), compile-time directives are out of this project's scope.
|
||
|
|
||
|
A full example would be: `<MyComponent vMyDirective:argument_modifier1_modifier2={someExpression} />`
|