Alpine 3.x Tips and Tricks

At the time of writing this article, Alpine Day has finished and Alpine 3.x has only been out a few hours. Some of the cool things that came with the new release are:

• An official website!
• First-party global stores.
• A new and improved reactivity engine.
• Improved CSP (Content-Security Policy) support.
• And much, much more...

I've only had my hands on it for a few hours, just like everybody else, but I've already had a big dive through the source code and here are a couple of things I've found.

1. Automatic init function calls

The new documentation states that components powered by Alpine.data declarations that contain an init function will automatically have the init function called. This is great and saves you some time since you don't need to hook up the x-init directive.

After reading through the source code, it turns out you can actually add an init function to any data object and Alpine will still call that function automatically.

<div x-data="{
    init() {
        console.log('Here we go!')
    }
}"></div>

When this component is initialized, the init function will be called automatically and the console.log will appear in your DevTools.

2. Clean up after yourself with destroy

Anybody familiar with PHP will likely know about the __destruct magic method. This method is called when an object is garbage collected, allowing you to clean up or free other resources manually.

Alpine 3.x also introduces a similar pattern for components through the use of destroy method. This method will be called when the component is removed from the DOM,

A good example might be a carousel or image gallery library that modifies the DOM outside of your component, or isn't handled directly by Alpine.

<div x-data="{
    init() {
        carouselLibrary.create();
    },
    destroy() {
        carouselLibrary.delete();
    }
}"></div>

Alpine will call the destroy method, allowing you to clean up after yourself.

This feature hasn't been documented yet. Please use with caution.

3. Interact with global stores from external JavaScript

This is something that Spruce supported to, so if you used that with Alpine 2.x you'll be familiar with this one.

Creating a store with Alpine.store allows you to access global state in your components using a $store property. That same Alpine.store method can be used to retrieve a store in your external scripts.

Alpine.store('counter', {
    count: 0
})

// In a different file or area.
Alpine.store('counter').count += 1

Calling Alpine.store with a single argument will return the Proxy instance for that particular store. Awesome, right?

4. Independent x-init directives

This one is mentioned in the documentation, but you can declare x-init on its own, inside or outside of an Alpine component.

This was a question that got asked so much previously -- people were getting frustrated with adding x-init and nothing happening.

<div x-data>
    <p x-init="console.log('I am ready!')"></p>
</div>

<img src="..." x-init="doSomeMagicHere()">

This is great for elements that don't need any state and just need to call another method or third-party library on initialisation.

5. Unfurl / unwrap Proxy with Alpine.raw

When debugging an issue in a component, 9 times out of 10 we turn to console.log(). This is fine in most cases. Other times, people get confused by the appearance of a Proxy in their console window.

This is somewhat annoying since expanding the object will give you [[Target]] and [[Handler]] which can be confusing.

To save you some confusion, you can use Alpine.raw inside of your console.log() calls. This method will unfurl / unwrap the Proxy instance created by Alpine and return the underlying value, i.e. the plain object, array, etc.

<div x-data="{ user: { name: 'Ryan' } }" x-init="console.log(user)">
    <!-- This produces a `Proxy` in the console -->
</div>

<div x-data="{ user: { name: 'Ryan' } }" x-init="console.log(Alpine.raw(user))">
    <!-- This produces the "real" `user` object in the console -->
</div>

And that's it from me, at least for now. I'll be working hard over the next couple of weeks trying to find other tips and tricks. In the meantime you can find me on Twitter and GitHub.