Vue composition API for AlpineJS
npm install alpine-composition_Vue composition API for AlpineJS._
``ts
import { defineComponent, registerComponent } from 'alpine-composition';
import { setAlpine } from 'alpine-reactivity';
// If the Alpine package is NOT available globally under
// window.Alpine, set it here
setAlpine(Alpine);
// Define component similarly to defining Vue components
const Button = defineComponent({
name: 'Button',
// Props are defined the same way as with Vue
props: {
name: {
type: String,
required: true,
},
startCount: {
type: Number,
default: 0,
},
},
// Instead of Alpine's init(), use setup()
// - Props are passed down as reactive props, same as in Vue
// - Second argument is the Alpine component instance.
// - Third argument is reactivity API that is scoped to destroy references
// when the component is destroyed.
// - Any additional args are inputs to x-data
setup(props, vm, reactivity, ...args) {
const { ref, toRefs, computed, watch, onBeforeUnmount } = reactivity;
const { name, startCount } = toRefs(props);
// Inside setup() you can use reactivity and composables
const counter = ref(startCount.value);
const { increaseCounter, disposeCounter } = useCounter(counter);
const countFormatted = computed(() => {
return Clicked button ${name.name} ${counter.value} times!
});
watch(counter, () => {
// NOTE: this is undefined in setup(). Instead, usevm
// the second argument to access the component instance.
vm.$dispatch('clicked', counter.value);
});
const onClick = () => {
increaseCounter();
};
// Instead of Alpine's destroy(), use $onBeforeUnmount().onBeforeUnmount
// This behaves like Vue's - it can be calleddestroy
// as many times as necessary.
// At component's event, all callbacks will be evaluated:
onBeforeUnmount(() => {
disposeCounter();
});
return {
counter,
countFormatted,
onClick,
};
},
});
`
This is where the magic happens. registerComponent is a wrapper for Alpine.data,setup
and it's thanks to this function that the component accepts props, has method,
and more.
`ts
import { registerComponent } from 'alpine-composition';
document.addEventListener('alpine:init', () => {
registerComponent(Alpine, Button);
});
`
` html
x-props="{ startCount: inputValue, name: 'MyButton' }"
>
Installation
$3
html
`js
const { defineComponent, registerComponent } = AlpineComposition;const Button = defineComponent({
name: 'Button',
props: { ... },
setup() { ... },
});
`$3
sh
npm install alpine-composition
`js
import { defineComponent, registerComponent } from 'alpine-composition';const Button = defineComponent({
name: 'Button',
props: { ... },
setup() { ... },
});
`Setup context and Magics
Inside of the
method, you can access the Alpine component instance
as the second argument. This instance has all Alpine magics.alpine-composition adds 8 more magics:-
$name - Name of the component. Readonly property.-
$props - Props passed to the component as reactive object.-
$attrs - HTML attributes (as object) of the element where the x-data was defined.-
$options - Component definition.-
$emitsOptions - Emits definition.-
$initState - Initial state, set via data-x-init, see below.-
$emit - Vue-like emit() method. Unlike $dispatch, $emit expects event handlers
to be set as props (e.g. onClickButton or onClickButtonOnce for event 'clickButton').
Thus, handlers for events emitted with $emit() must be explicitly defined on the component
that emits that event. In other words, the even does NOT bubble up. And when no event handler
is passed as a prop, the event is NOT sent. Similar to Vue, the
$emit method has the event names and inputs autoamtically inferred from
the component options when using TypeScript.-
$onBeforeUnmount - Equivalent of Vue's onBeforeUnmount.
Use this instead of Alpine's destroy hook.`ts
import { defineComponent } from 'alpine-composition';const Button = defineComponent({
name: 'Button',
setup(props, vm, reactivity) {
const { ref, computed, watch, onBeforeUnmount } = reactivity;
const nameEl = vm.$el.querySelector('input[name="name"]');
console.log(vm.$name);
onBeforeUnmount(() => {
doUnregisterSomething();
});
const inputVal = ref('');
watch(inputVal, (newVal, oldVal) => {
// Send an event that can be captured with
//
x-on:input directive
vm.$dispatch('input', newVal); // Send an event that can be captured with
//
onInput prop
vm.$emit('input', newVal);
}, { immediate: true });
},
});
`Component isolation
To make the Alpine components behave more like Vue, the components created by
are automatically isolated from outer components. This can
be disabled by setting isolated: false on the component.Normally when you have an Alpine components like so:
`html
`Then the inner component has access to the scope (data) from the outer components:
html
`However, to mimic Vue API, we need to explicitly pass down data as props.
Because of this, components don't have access to the outer scopes:
html
`To allow access to outer scopes, set
on the component definition:`ts
const Button = defineComponent({
name: 'Button',
props: { ... },
setup() { ... }, isolated: false,
});
`Initializing component state from HTML
Sometimes, you may want to initialize a component to a certain state,
without exposing the inner state as props.
Imagine we have a button component, and we want to set the button width
at page load. We want different buttons to have different width,
but we want the width to remain constant for the rest of its existence.
For this
allows to set the internal component state
from JSON, passed to the component as data-x-init attribute:`ts
import { defineComponent, registerComponent } from 'alpine-composition';const Button = defineComponent({
name: 'Button',
setup(props, vm) {
// Either use the value defined outside, or default to '20px'
const buttonWidth = vm.$initState.buttonWidth || '20px';
const buttonStyle =
width: ${buttonWidth}; height: 40px; background: yellow;; return {
buttonStyle,
};
},
});
`Where does the value
come from? This is taken from the
component's initial state. See below:`html
`You can change which data key is used for initial data by setting the
option.initKey should be a valid HTML attribute - it should be lowercase, and contain only
letters and dashes.initKey will be prefixed with x- to avoid conflicts.So, in the example below, we can define the initial state via the
data-x-my-init
attribute by setting the option to my-init:`ts
const Button = defineComponent({
name: 'Button',
initKey: 'my-init',
setup(props, vm) { ... },
});
`html
`Extending
comes with a plugin system that allows you to modify the Alpine instance
for each component registered with the respective registerComponent function.The example below is taken from Alpinui. Here, we defined a plugin for new magic
attribute
$aliasName accessible inside the setup() method. $aliasName returns
the value of aliasName component option.`ts
import {
createAlpineComposition,
defineComponent,
type Data,
type PluginFn,
} from 'alpine-composition';import type { Alpine as AlpineType } from 'alpinejs';
import type { Magics } from 'alpinejs';
export interface CreateAlpinuiOptions {
components?: Record;
}
// Extend the types, so we get type hints for
vm.$aliasName
// and can specify aliasName on the component definition.
declare module 'alpine-composition' {
interface AlpineInstance extends Magics
{
$aliasName?: string;
}
interface ComponentOptions {
aliasName?: string;
}
}
// Alpinui adds
$aliasName to the Alpine components
// Plugins receive the VM as the first arg, and context as second.
const aliasNamePlugin: PluginFn = (vm, { options }) => {
const { aliasName } = options; Object.defineProperty(vm, '$aliasName', {
get() {
return aliasName;
},
});
};
/* Register Alpinui components with Alpine /
export function createAlpinui(
options: CreateAlpinuiOptions = {},
) {
const { components = {} } = options;
// We pass the plugins to
createAlpineComposition.
// This returns an instance of registerComponent function.
// This behaves the same as the module-level registerComponent,
// except it also calls our plugins.
const { registerComponent } = createAlpineComposition({
plugins: [
aliasNamePlugin,
],
}); // Alpinui allows users to provide their own instance of Alpine
// via install()
const install = (Alpine: AlpineType) => {
for (const key in components) {
registerComponent(Alpine, components[key]);
}
};
return {
install,
registerComponent,
};
}
`After we have created
, we can register components with it like so:`ts
import { defineComponent } from 'alpine-composition';const Button = defineComponent({
name: 'Button',
props: { ... },
setup() { ... },
aliasName: 'ButtonAlias',
});
const alpinui = createAlpinui({
components: { ... },
});
// NOTE: We use the newly created
registerComponent,
// NOT the one from alpine-composition
alpinui.registerComponent(Alpine, Button);