Alpine.js offers you the reactive and declarative nature of big frameworks like Vue or React at a much lower cost.
You get to keep your DOM, and sprinkle in behavior as you see fit.
Think of it like Tailwind for JavaScript.
Note: This tool's syntax is almost entirely borrowed from Vue (and by extension Angular). I am forever grateful for the gift they are to the web.
Language | Link for documentation |
---|---|
Arabic | التوثيق باللغة العربية |
Chinese Simplified | 简体中文文档 |
Chinese Traditional | 繁體中文說明文件 |
German | Dokumentation in Deutsch |
Indonesian | Dokumentasi Bahasa Indonesia |
Japanese | 日本語ドキュメント |
Portuguese | Documentação em Português |
Russian | Документация на русском |
Spanish | Documentación en Español |
Turkish | Türkçe Dokümantasyon |
Français | Documentation en Français |
Korean | 한국어 문서 |
From CDN: Add the following script to the end of your <head>
section.
<script src="https://cdn.jsdelivr.net/gh/alpinejs/[email protected]/dist/alpine.min.js" defer></script>
That's it. It will initialize itself.
For production environments, it's recommended to pin a specific version number in the link to avoid unexpected breakage from newer versions.
For example, to use version 2.8.1
(latest):
<script src="https://cdn.jsdelivr.net/gh/alpinejs/[email protected]/dist/alpine.min.js" defer></script>
From npm: Install the package from npm.
npm i alpinejs
Include it in your script.
import 'alpinejs'
For IE11 support Use the following scripts instead.
<script type="module" src="https://cdn.jsdelivr.net/gh/alpinejs/[email protected]/dist/alpine.min.js"></script>
<script nomodule src="https://cdn.jsdelivr.net/gh/alpinejs/[email protected]/dist/alpine-ie11.min.js" defer></script>
The pattern above is the module/nomodule pattern that will result in the modern bundle automatically loaded on modern browsers, and the IE11 bundle loaded automatically on IE11 and other legacy browsers.
Dropdown/Modal
<div x-data="{ open: false }">
<button @click="open = true">Open Dropdown</button>
<ul
x-show="open"
@click.away="open = false"
>
Dropdown Body
</ul>
</div>
Tabs
<div x-data="{ tab: 'foo' }">
<button :class="{ 'active': tab === 'foo' }" @click="tab = 'foo'">Foo</button>
<button :class="{ 'active': tab === 'bar' }" @click="tab = 'bar'">Bar</button>
<div x-show="tab === 'foo'">Tab Foo</div>
<div x-show="tab === 'bar'">Tab Bar</div>
</div>
You can even use it for non-trivial things: Pre-fetching a dropdown's HTML content on hover.
<div x-data="{ open: false }">
<button
@mouseenter.once="
fetch('/dropdown-partial.html')
.then(response => response.text())
.then(html => { $refs.dropdown.innerHTML = html })
"
@click="open = true"
>Show Dropdown</button>
<div x-ref="dropdown" x-show="open" @click.away="open = false">
Loading Spinner...
</div>
</div>
There are 14 directives available to you:
Directive | Description |
---|---|
x-data |
Declares a new component scope. |
x-init |
Runs an expression when a component is initialized. |
x-show |
Toggles display: none; on the element depending on expression (true or false). |
x-bind |
Sets the value of an attribute to the result of a JS expression. |
x-on |
Attaches an event listener to the element. Executes JS expression when emitted. |
x-model |
Adds "two-way data binding" to an element. Keeps input element in sync with component data. |
x-text |
Works similarly to x-bind , but will update the innerText of an element. |
x-html |
Works similarly to x-bind , but will update the innerHTML of an element. |
x-ref |
Convenient way to retrieve raw DOM elements out of your component. |
x-if |
Remove an element completely from the DOM. Needs to be used on a <template> tag. |
x-for |
Create new DOM nodes for each item in an array. Needs to be used on a <template> tag. |
x-transition |
Directives for applying classes to various stages of an element's transition. |
x-spread |
Allows you to bind an object of Alpine directives to an element for better reusability. |
x-cloak |
This attribute is removed when Alpine initializes. Useful for hiding pre-initialized DOM. |
And 6 magic properties:
Magic Properties | Description |
---|---|
$el |
Retrieve the root component DOM node. |
$refs |
Retrieve DOM elements marked with x-ref inside the component. |
$event |
Retrieve the native browser "Event" object within an event listener. |
$dispatch |
Create a CustomEvent and dispatch it using .dispatchEvent() internally. |
$nextTick |
Execute a given expression AFTER Alpine has made its reactive DOM updates. |
$watch |
Will fire a provided callback when a component property you "watched" gets changed. |
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- Alpine Devtools
- Alpine Magic Helpers
- Alpine Weekly Newsletter
- Spruce (State Management)
- Awesome Alpine
- Turbolinks Adapter
Example: <div x-data="{ foo: 'bar' }">...</div>
Structure: <div x-data="[object literal]">...</div>
x-data
declares a new component scope. It tells the framework to initialize a new component with the following data object.
Think of it like the data
property of a Vue component.
Extract Component Logic
You can extract data (and behavior) into reusable functions:
<div x-data="dropdown()">
<button x-on:click="open">Open</button>
<div x-show="isOpen()" x-on:click.away="close">
// Dropdown
</div>
</div>
<script>
function dropdown() {
return {
show: false,
open() { this.show = true },
close() { this.show = false },
isOpen() { return this.show === true },
}
}
</script>
For bundler users, note that Alpine.js accesses functions that are in the global scope (
window
), you'll need to explicitly assign your functions towindow
in order to use them withx-data
for examplewindow.dropdown = function () {}
(this is because with Webpack, Rollup, Parcel etc.function
's you define will default to the module's scope notwindow
).
You can also mix-in multiple data objects using object destructuring:
<div x-data="{...dropdown(), ...tabs()}">
Example: <div x-data="{ foo: 'bar' }" x-init="foo = 'baz'"></div>
Structure: <div x-data="..." x-init="[expression]"></div>
x-init
runs an expression when a component is initialized.
If you wish to run code AFTER Alpine has made its initial updates to the DOM (something like a mounted()
hook in VueJS), you can return a callback from x-init
, and it will be run after:
x-init="() => { // we have access to the post-dom-initialization state here // }"
Example: <div x-show="open"></div>
Structure: <div x-show="[expression]"></div>
x-show
toggles the display: none;
style on the element depending if the expression resolves to true
or false
.
x-show.transition
x-show.transition
is a convenience API for making your x-show
s more pleasant using CSS transitions.
<div x-show.transition="open">
These contents will be transitioned in and out.
</div>
Directive | Description |
---|---|
x-show.transition |
A simultaneous fade and scale. (opacity, scale: 0.95, timing-function: cubic-bezier(0.4, 0.0, 0.2, 1), duration-in: 150ms, duration-out: 75ms) |
x-show.transition.in |
Only transition in. |
x-show.transition.out |
Only transition out. |
x-show.transition.opacity |
Only use the fade. |
x-show.transition.scale |
Only use the scale. |
x-show.transition.scale.75 |
Customize the CSS scale transform transform: scale(.75) . |
x-show.transition.duration.200ms |
Sets the "in" transition to 200ms. The out will be set to half that (100ms). |
x-show.transition.origin.top.right |
Customize the CSS transform origin transform-origin: top right . |
x-show.transition.in.duration.200ms.out.duration.50ms |
Different durations for "in" and "out". |
Note: All of these transition modifiers can be used in conjunction with each other. This is possible (although ridiculous lol):
x-show.transition.in.duration.100ms.origin.top.right.opacity.scale.85.out.duration.200ms.origin.bottom.left.opacity.scale.95
Note:
x-show
will wait for any children to finish transitioning out. If you want to bypass this behavior, add the.immediate
modifier:
<div x-show.immediate="open">
<div x-show.transition="open">
</div>
Note: You are free to use the shorter ":" syntax:
:type="..."
.
Example: <input x-bind:type="inputType">
Structure: <input x-bind:[attribute]="[expression]">
x-bind
sets the value of an attribute to the result of a JavaScript expression. The expression has access to all the keys of the component's data object, and will update every-time its data is updated.
Note: attribute bindings ONLY update when their dependencies update. The framework is smart enough to observe data changes and detect which bindings care about them.
x-bind
for class attributes
x-bind
behaves a little differently when binding to the class
attribute.
For classes, you pass in an object whose keys are class names, and values are boolean expressions to determine if those class names are applied or not.
For example:
<div x-bind:class="{ 'hidden': foo }"></div>
In this example, the "hidden" class will only be applied when the value of the foo
data attribute is true
.
x-bind
for boolean attributes
x-bind
supports boolean attributes in the same way as value attributes, using a variable as the condition or any JavaScript expression that resolves to true
or false
.
For example:
<!-- Given: -->
<button x-bind:disabled="myVar">Click me</button>
<!-- When myVar == true: -->
<button disabled="disabled">Click me</button>
<!-- When myVar == false: -->
<button>Click me</button>
This will add or remove the disabled
attribute when myVar
is true or false respectively.
Boolean attributes are supported as per the HTML specification, for example disabled
, readonly
, required
, checked
, hidden
, selected
, open
, etc.
Note: If you need a false state to show for your attribute, such as
aria-*
, chain.toString()
to the value while binding to the attribute. For example::aria-expanded="isOpen.toString()"
would persist whetherisOpen
wastrue
orfalse
.
.camel
modifier
Example: <svg x-bind:view-box.camel="viewBox">
The camel
modifier will bind to the camel case equivalent of the attribute name. In the example above, the value of viewBox
will be bound the viewBox
attribute as opposed to the view-box
attribute.
Note: You are free to use the shorter "@" syntax:
@click="..."
.
Example: <button x-on:click="foo = 'bar'"></button>
Structure: <button x-on:[event]="[expression]"></button>
x-on
attaches an event listener to the element it's declared on. When that event is emitted, the JavaScript expression set as its value is executed. You can use x-on
with any event available for the element you're adding the directive on, for a full list of events, see the Event reference on MDN for a list of possible values.
If any data is modified in the expression, other element attributes "bound" to this data, will be updated.
Note: You can also specify a JavaScript function name.
Example: <button x-on:click="myFunction"></button>
This is equivalent to: <button x-on:click="myFunction($event)"></button>
keydown
modifiers
Example: <input type="text" x-on:keydown.escape="open = false">
You can specify specific keys to listen for using keydown modifiers appended to the x-on:keydown
directive. Note that the modifiers are kebab-cased versions of Event.key
values.
Examples: enter
, escape
, arrow-up
, arrow-down
Note: You can also listen for system-modifier key combinations like:
x-on:keydown.cmd.enter="foo"
.away
modifier
Example: <div x-on:click.away="showModal = false"></div>
When the .away
modifier is present, the event handler will only be executed when the event originates from a source other than itself, or its children.
This is useful for hiding dropdowns and modals when a user clicks away from them.
.prevent
modifier
Example: <input type="checkbox" x-on:click.prevent>
Adding .prevent
to an event listener will call preventDefault
on the triggered event. In the above example, this means the checkbox wouldn't actually get checked when a user clicks on it.
.stop
modifier
Example: <div x-on:click="foo = 'bar'"><button x-on:click.stop></button></div>
Adding .stop
to an event listener will call stopPropagation
on the triggered event. In the above example, this means the "click" event won't bubble from the button to the outer <div>
. Or in other words, when a user clicks the button, foo
won't be set to 'bar'
.
.self
modifier
Example: <div x-on:click.self="foo = 'bar'"><button></button></div>
Adding .self
to an event listener will only trigger the handler if the $event.target
is the element itself. In the above example, this means the "click" event that bubbles from the button to the outer <div>
will not run the handler.
.window
modifier
Example: <div x-on:resize.window="isOpen = window.outerWidth > 768 ? false : open"></div>
Adding .window
to an event listener will install the listener on the global window object instead of the DOM node on which it is declared. This is useful for when you want to modify component state when something changes with the window, like the resize event. In this example, when the window grows larger than 768 pixels wide, we will close the modal/dropdown, otherwise maintain the same state.
Note: You can also use the
.document
modifier to attach listeners todocument
instead ofwindow
.once
modifier
Example: <button x-on:mouseenter.once="fetchSomething()"></button>
Adding the .once
modifier to an event listener will ensure that the listener will only be handled once. This is useful for things you only want to do once, like fetching HTML partials and such.
.passive
modifier
Example: <button x-on:mousedown.passive="interactive = true"></button>
Adding the .passive
modifier to an event listener will make the listener a passive one, which means preventDefault()
will not work on any events being processed, this can help, for example with scroll performance on touch devices.
.debounce
modifier
Example: <input x-on:input.debounce="fetchSomething()">
The debounce
modifier allows you to "debounce" an event handler. In other words, the event handler will NOT run until a certain amount of time has elapsed since the last event that fired. When the handler is ready to be called, the last handler call will execute.
The default debounce "wait" time is 250 milliseconds.
If you wish to customize this, you can specify a custom wait time like so:
<input x-on:input.debounce.750="fetchSomething()">
<input x-on:input.debounce.750ms="fetchSomething()">
.camel
modifier
Example: <input x-on:event-name.camel="doSomething()">
The camel
modifier will attach an event listener for the camel case equivalent event name. In the example above, the expression will be evaluated when the eventName
event is fired on the element.
Example: <input type="text" x-model="foo">
Structure: <input type="text" x-model="[data item]">
x-model
adds "two-way data binding" to an element. In other words, the value of the input element will be kept in sync with the value of the data item of the component.
Note:
x-model
is smart enough to detect changes on text inputs, checkboxes, radio buttons, textareas, selects, and multiple selects. It should behave how Vue would in those scenarios.
.number
modifier
Example: <input x-model.number="age">
The number
modifier will convert the input's value to a number. If the value cannot be parsed as a valid number, the original value is returned.
.debounce
modifier
Example: <input x-model.debounce="search">
The debounce
modifier allows you to add a "debounce" to a value update. In other words, the event handler will NOT run until a certain amount of time has elapsed since the last event that fired. When the handler is ready to be called, the last handler call will execute.
The default debounce "wait" time is 250 milliseconds.
If you wish to customize this, you can specifiy a custom wait time like so:
<input x-model.debounce.750="search">
<input x-model.debounce.750ms="search">
Example: <span x-text="foo"></span>
Structure: <span x-text="[expression]"
x-text
works similarly to x-bind
, except instead of updating the value of an attribute, it will update the innerText
of an element.
Example: <span x-html="foo"></span>
Structure: <span x-html="[expression]"
x-html
works similarly to x-bind
, except instead of updating the value of an attribute, it will update the innerHTML
of an element.
⚠️ Only use on trusted content and never on user-provided content.⚠️ Dynamically rendering HTML from third parties can easily lead to XSS vulnerabilities.
Example: <div x-ref="foo"></div><button x-on:click="$refs.foo.innerText = 'bar'"></button>
Structure: <div x-ref="[ref name]"></div><button x-on:click="$refs.[ref name].innerText = 'bar'"></button>
x-ref
provides a convenient way to retrieve raw DOM elements out of your component. By setting an x-ref
attribute on an element, you are making it available to all event handlers inside an object called $refs
.
This is a helpful alternative to setting ids and using document.querySelector
all over the place.
Note: you can also bind dynamic values for x-ref:
<span :x-ref="item.id"></span>
if you need to.
Example: <template x-if="true"><div>Some Element</div></template>
Structure: <template x-if="[expression]"><div>Some Element</div></template>
For cases where x-show
isn't sufficient (x-show
sets an element to display: none
if it's false), x-if
can be used to actually remove an element completely from the DOM.
It's important that x-if
is used on a <template></template>
tag because Alpine doesn't use a virtual DOM. This implementation allows Alpine to stay rugged and use the real DOM to work its magic.
Note:
x-if
must have a single root element inside the<template></template>
tag.
Note: When using
template
in asvg
tag, you need to add a polyfill that should be run before Alpine.js is initialized.
Example:
<template x-for="item in items" :key="item">
<div x-text="item"></div>
</template>
Note: the
:key
binding is optional, but HIGHLY recommended.
x-for
is available for cases when you want to create new DOM nodes for each item in an array. This should appear similar to v-for
in Vue, with one exception of needing to exist on a template
tag, and not a regular DOM element.
If you want to access the current index of the iteration, use the following syntax:
<template x-for="(item, index) in items" :key="index">
<!-- You can also reference "index" inside the iteration if you need. -->
<div x-text="index"></div>
</template>
If you want to access the array object (collection) of the iteration, use the following syntax:
<template x-for="(item, index, collection) in items" :key="index">
<div>
<!-- You can also reference "collection" inside the iteration if you need. -->
<!-- Current item. -->
<div x-text="item"></div>
<!-- Same as above. -->
<div x-text="collection[index]"></div>
<!-- Previous item. -->
<div x-text="collection[index - 1]"></div>
</div>
</template>
Note:
x-for
must have a single root element inside of the<template></template>
tag.
Note: When using
template
in asvg
tag, you need to add a polyfill that should be run before Alpine.js is initialized.
You can nest x-for
loops, but you MUST wrap each loop in an element. For example:
<template x-for="item in items">
<div>
<template x-for="subItem in item.subItems">
<div x-text="subItem"></div>
</template>
</div>
</template>
Alpine supports the i in n
syntax, where n
is an integer, allowing you to iterate over a fixed range of elements.
<template x-for="i in 10">
<span x-text="i"></span>
</template>
Example:
<div
x-show="open"
x-transition:enter="transition ease-out duration-300"
x-transition:enter-start="opacity-0 transform scale-90"
x-transition:enter-end="opacity-100 transform scale-100"
x-transition:leave="transition ease-in duration-300"
x-transition:leave-start="opacity-100 transform scale-100"
x-transition:leave-end="opacity-0 transform scale-90"
>...</div>
<template x-if="open">
<div
x-transition:enter="transition ease-out duration-300"
x-transition:enter-start="opacity-0 transform scale-90"
x-transition:enter-end="opacity-100 transform scale-100"
x-transition:leave="transition ease-in duration-300"
x-transition:leave-start="opacity-100 transform scale-100"
x-transition:leave-end="opacity-0 transform scale-90"
>...</div>
</template>
The example above uses classes from Tailwind CSS.
Alpine offers 6 different transition directives for applying classes to various stages of an element's transition between "hidden" and "shown" states. These directives work both with x-show
AND x-if
.
These behave exactly like VueJS's transition directives, except they have different, more sensible names:
Directive | Description |
---|---|
:enter |
Applied during the entire entering phase. |
:enter-start |
Added before element is inserted, removed one frame after element is inserted. |
:enter-end |
Added one frame after element is inserted (at the same time enter-start is removed), removed when transition/animation finishes. |
:leave |
Applied during the entire leaving phase. |
:leave-start |
Added immediately when a leaving transition is triggered, removed after one frame. |
:leave-end |
Added one frame after a leaving transition is triggered (at the same time leave-start is removed), removed when the transition/animation finishes. |
Example:
<div x-data="dropdown()">
<button x-spread="trigger">Open Dropdown</button>
<span x-spread="dialogue">Dropdown Contents</span>
</div>
<script>
function dropdown() {
return {
open: false,
trigger: {
['@click']() {
this.open = true
},
},
dialogue: {
['x-show']() {
return this.open
},
['@click.away']() {
this.open = false
},
}
}
}
</script>
x-spread
allows you to extract an element's Alpine bindings into a reusable object.
The object keys are the directives (Can be any directive including modifiers), and the values are callbacks to be evaluated by Alpine.
Note: There are a couple of caveats to x-spread:
- When the directive being "spread" is
x-for
, you should return a normal expression string from the callback. For example:['x-for']() { return 'item in items' }
.x-data
andx-init
can't be used inside a "spread" object.
Example: <div x-data="{}" x-cloak></div>
x-cloak
attributes are removed from elements when Alpine initializes. This is useful for hiding pre-initialized DOM. It's typical to add the following global style for this to work:
<style>
[x-cloak] {
display: none !important;
}
</style>
With the exception of
$el
, magic properties are not available withinx-data
as the component isn't initialized yet.
Example:
<div x-data>
<button @click="$el.innerHTML = 'foo'">Replace me with "foo"</button>
</div>
$el
is a magic property that can be used to retrieve the root component DOM node.
Example:
<span x-ref="foo"></span>
<button x-on:click="$refs.foo.innerText = 'bar'"></button>
$refs
is a magic property that can be used to retrieve DOM elements marked with x-ref
inside the component. This is useful when you need to manually manipulate DOM elements.
Example:
<input x-on:input="alert($event.target.value)">
$event
is a magic property that can be used within an event listener to retrieve the native browser "Event" object.
Note: The $event property is only available in DOM expressions.
If you need to access $event inside of a JavaScript function you can pass it in directly:
<button x-on:click="myFunction($event)"></button>
Example:
<div @custom-event="console.log($event.detail.foo)">
<button @click="$dispatch('custom-event', { foo: 'bar' })">
<!-- When clicked, will console.log "bar" -->
</div>
Note on Event Propagation
Notice that, because of event bubbling, when you need to capture events dispatched from nodes that are under the same nesting hierarchy, you'll need to use the .window
modifier:
Example:
<div x-data>
<span @custom-event="console.log($event.detail.foo)"></span>
<button @click="$dispatch('custom-event', { foo: 'bar' })">
<div>
This won't work because when
custom-event
is dispatched, it'll propagate to its common ancestor, thediv
.
Dispatching to Components
You can also take advantage of the previous technique to make your components talk to each other:
Example:
<div x-data @custom-event.window="console.log($event.detail)"></div>
<button x-data @click="$dispatch('custom-event', 'Hello World!')">
<!-- When clicked, will console.log "Hello World!". -->
$dispatch
is a shortcut for creating a CustomEvent
and dispatching it using .dispatchEvent()
internally. There are lots of good use cases for passing data around and between components using custom events. Read here for more information on the underlying CustomEvent
system in browsers.
You will notice that any data passed as the second parameter to $dispatch('some-event', { some: 'data' })
, becomes available through the new events "detail" property: $event.detail.some
. Attaching custom event data to the .detail
property is standard practice for CustomEvent
s in browsers. Read here for more info.
You can also use $dispatch()
to trigger data updates for x-model
bindings. For example:
<div x-data="{ foo: 'bar' }">
<span x-model="foo">
<button @click="$dispatch('input', 'baz')">
<!-- After the button is clicked, `x-model` will catch the bubbling "input" event, and update foo to "baz". -->
</span>
</div>
Note: The $dispatch property is only available in DOM expressions.
If you need to access $dispatch inside of a JavaScript function you can pass it in directly:
<button x-on:click="myFunction($dispatch)"></button>
Example:
<div x-data="{ fruit: 'apple' }">
<button
x-on:click="
fruit = 'pear';
$nextTick(() => { console.log($event.target.innerText) });
"
x-text="fruit"
></button>
</div>
$nextTick
is a magic property that allows you to only execute a given expression AFTER Alpine has made its reactive DOM updates. This is useful for times you want to interact with the DOM state AFTER it's reflected any data updates you've made.
Example:
<div x-data="{ open: false }" x-init="$watch('open', value => console.log(value))">
<button @click="open = ! open">Toggle Open</button>
</div>
You can "watch" a component property with the $watch
magic method. In the above example, when the button is clicked and open
is changed, the provided callback will fire and console.log
the new value.
If you find a security vulnerability, please send an email to [email protected].
Alpine relies on a custom implementation using the Function
object to evaluate its directives. Despite being more secure then eval()
, its use is prohibited in some environments, such as Google Chrome App, using restrictive Content Security Policy (CSP).
If you use Alpine in a website dealing with sensitive data and requiring CSP, you need to include unsafe-eval
in your policy. A robust policy correctly configured will help protecting your users when using personal or financial data.
Since a policy applies to all scripts in your page, it's important that other external libraries included in the website are carefully reviewed to ensure that they are trustworthy and they won't introduce any Cross Site Scripting vulnerability either using the eval()
function or manipulating the DOM to inject malicious code in your page.
- Move from
x-ref
toref
for Vue parity? - Add
Alpine.directive()
- Add
Alpine.component('foo', {...})
(With magic__init()
method) - Dispatch Alpine events for "loaded", "transition-start", etc... (#299) ?
- Remove "object" (and array) syntax from
x-bind:class="{ 'foo': true }"
(#236 to add support for object syntax for thestyle
attribute) - Improve
x-for
mutation reactivity (#165) - Add "deep watching" support in V3 (#294)
- Add
$el
shortcut - Change
@click.away
to@click.outside
?
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