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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>

There are two rules worth noting about x-for:

Keys

It is important to specify 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.