Livewire Development

Livewire Development

When to Apply

Activate this skill when:

• Creating or modifying Livewire components
• Using wire: directives (model, click, loading, sort, intersect)
• Implementing islands or async actions
• Writing Livewire component tests

Documentation

Use search-docs for detailed Livewire 4 patterns and documentation.

Basic Usage

Creating Components

<code-snippet name="Component Creation Commands" lang="bash">

Single-file component (default in v4)

{{ $assist->artisanCommand('make:livewire create-post') }}

Multi-file component

{{ $assist->artisanCommand('make:livewire create-post --mfc') }}

Class-based component (v3 style)

{{ $assist->artisanCommand('make:livewire create-post --class') }}

With namespace

{{ $assist->artisanCommand('make:livewire Posts/CreatePost') }}

</code-snippet>

Converting Between Formats

Use php artisan livewire:convert create-post to convert between single-file, multi-file, and class-based formats.

Component Format Reference

Single-File Component Example

<code-snippet name="Single-File Component Example" lang="php">

<?php use Livewire\Component;

new class extends Component { public int $count = 0;

public function increment(): void { $this->count++; } } ?>

<div> <button wire:click="increment">Count: @{{ $count }}</button> </div>

</code-snippet>

Livewire 4 Specifics

Key Changes From Livewire 3

These things changed in Livewire 4, but may not have been updated in this application. Verify this application's setup to ensure you follow existing conventions.

• Use Route::livewire() for full-page components; config keys renamed: layout → component_layout, lazy_placeholder → component_placeholder.
• wire:model now ignores child events by default (use wire:model.deep for old behavior); wire:scroll renamed to wire:navigate:scroll.
• Component tags must be properly closed; wire:transition now uses View Transitions API (modifiers removed).
• JavaScript: $wire.$js('name', fn) → $wire.$js.name = fn; commit/request hooks → interceptMessage()/interceptRequest().

New Features

• Component formats: single-file (SFC), multi-file (MFC), view-based components.
• Islands (@island) for isolated updates; async actions (wire:click.async, #[Async]) for parallel execution.
• Deferred/bundled loading: defer, lazy.bundle for optimized component loading.

New Directives

• wire:sort, wire:intersect, wire:ref, .renderless, .preserve-scroll are available for use.
• data-loading attribute automatically added to elements triggering network requests.

Best Practices

• Always use wire:key in loops
• Use wire:loading for loading states
• Use wire:model.live for instant updates (default is debounced)
• Validate and authorize in actions (treat like HTTP requests)

Configuration

• smart_wire_keys defaults to true; new configs: component_locations, component_namespaces, make_command, csp_safe.

Alpine & JavaScript

• wire:transition uses browser View Transitions API; $errors and $intercept magic properties available.
• Non-blocking wire:poll and parallel wire:model.live updates improve performance.

For interceptors and hooks, see reference/javascript-hooks.md.

Testing

<code-snippet name="Testing Example" lang="php">

Livewire::test(Counter::class) ->assertSet('count', 0) ->call('increment') ->assertSet('count', 1);

</code-snippet>

Verification

1. Browser console: Check for JS errors 2. Network tab: Verify Livewire requests return 200 3. Ensure wire:key on all @foreach loops

Common Pitfalls

• Missing wire:key in loops → unexpected re-rendering
• Expecting wire:model real-time → use wire:model.live
• Unclosed component tags → syntax errors in v4
• Using deprecated config keys or JS hooks
• Including Alpine.js separately (already bundled in Livewire 4)

Livewire 4 JavaScript Integration

Interceptor System (v4)

Intercept Messages

Livewire.interceptMessage(({ component, message, onFinish, onSuccess, onError }) => {
    onFinish(() => { /* After response, before processing */ });
    onSuccess(({ payload }) => { /* payload.snapshot, payload.effects */ });
    onError(() => { /* Server errors */ });
});

Intercept Requests

Livewire.interceptRequest(({ request, onResponse, onSuccess, onError, onFailure }) => {
    onResponse(({ response }) => { /* When received */ });
    onSuccess(({ response, responseJson }) => { /* Success */ });
    onError(({ response, responseBody, preventDefault }) => { /* 4xx/5xx */ });
    onFailure(({ error }) => { /* Network failures */ });
});

Component-Scoped Interceptors

<script>
    this.$intercept('save', ({ component, onSuccess }) => {
        onSuccess(() => console.log('Saved!'));
    });
</script>

Magic Properties

• $errors - Access validation errors from JavaScript
• $intercept - Component-scoped interceptors