for
x-for
Alpine's x-for
directive allows you to create DOM elements by iterating through a list. Here's a simple example of using it to create a list of colors based on an array.
<ul x-data="{ colors: ['Red', 'Orange', 'Yellow'] }">
<template x-for="color in colors">
<li x-text="color"></li>
</template>
</ul>
<div class="demo">
<ul x-data="{ colors: ['Red', 'Orange', 'Yellow'] }">
<template x-for="color in colors">
<li x-text="color"></li>
</template>
</ul>
</div>
There are two rules worth noting about x-for
:
x-for
MUST be declared on a<template>
element- That
<template>
element MUST have only one root element
Keys
It is important to specify unique keys for each x-for
iteration if you are going to be re-ordering items. Without dynamic keys, Alpine may have a hard time keeping track of what re-orders and will cause odd side-effects.
<ul x-data="{ colors: [
{ id: 1, label: 'Red' },
{ id: 2, label: 'Orange' },
{ id: 3, label: 'Yellow' },
]}">
<template x-for="color in colors" :key="color.id">
<li x-text="color.label"></li>
</template>
</ul>
Now if the colors are added, removed, re-ordered, or their "id"s change, Alpine will preserve or destroy the iterated <li>
elements accordingly.
Accessing indexes
If you need to access the index of each item in the iteration, you can do so using the ([item], [index]) in [items]
syntax like so:
<ul x-data="{ colors: ['Red', 'Orange', 'Yellow'] }">
<template x-for="(color, index) in colors">
<li>
<span x-text="index + ': '"></span>
<span x-text="color"></span>
</li>
</template>
</ul>
You can also access the index inside a dynamic :key
expression.
<template x-for="(color, index) in colors" :key="index">
Iterating over a range
If you need to simply loop n
number of times, rather than iterate through an array, Alpine offers a short syntax.
<ul>
<template x-for="i in 10">
<li x-text="i"></li>
</template>
</ul>
i
in this case can be named anything you like.