Livewire component design

Livewire Component Design

Every Livewire interaction is a network round-trip carrying component state. Good component design minimizes what crosses the wire and who owns what.

When to use

• Creating or splitting Livewire components ("one big component or three small?")
• State desync, unexpected re-renders, or lost input
• A Livewire page feels sluggish (too many/too heavy requests)
• Deciding Livewire vs Alpine for an interaction

Principles

• Components own state; children receive data and emit events. Two components owning the same state will disagree.
• Alpine for the browser, Livewire for the server. Toggles, tabs, dropdowns = Alpine (zero round-trips). Anything touching data/authorization = Livewire.
• Public properties are the payload — and the attack surface. Everything public crosses the wire every request and can be tampered with client-side. Keep it minimal, validate/authorize server-side always.
• A component is a unit of update, not a unit of markup. Split where update frequency differs, not where the design grid does.

Process

1. Decide what's a component

• Split when a region updates independently (search results vs filters vs cart badge)
• Don't split static markup into components — Blade partials/components are free, Livewire components are not
• Page-level component + small interactive islands beats a deep nesting tree

2. Assign state ownership

• The owner mutates; everyone else reads
• Parent → child: pass data as props (child re-renders when parent re-renders)
• Child → parent: dispatch events ($this->dispatch('order-updated')), parent listens with #[On('order-updated')]
• Cross-component shared state (cart count in navbar): events, or re-fetch in the listener — don't mirror writable copies

3. Keep the payload lean

• Public properties: scalars, arrays, IDs. Prefer passing IDs + #[Computed] lookups over fat serialized models
• #[Computed] for derived data — cached per request, doesn't ride the payload
• #[Locked] on IDs and anything the client must not change (public #[Locked] int $orderId)
• Never put secrets or other users' data in public properties — view-source shows them

4. Control the round-trips

Pattern	Use
wire:model.live.debounce.300ms	Search-as-you-type (default wire:model is deferred — already cheap)
wire:model.blur	Validate a field on blur
Alpine (x-show, x-data)	Pure UI state — no server trip at all
#[Lazy] component	Below-the-fold or expensive components; loads after page paint
Polling wire:poll.10s	Sparingly; prefer events/broadcasts for real-time
wire:loading / optimistic UI	Mask unavoidable latency

5. Forms

• Form objects (UserForm extends Form) once a form exceeds a few fields — validation rules, state, and save() live together
• Real-time validation: wire:model.blur + $this->validateOnly($field)
• Always re-validate and re-authorize in the action method — client state is untrusted input

6. Test it

Livewire::test(OrderTable::class)
    ->set('search', 'foo')
    ->assertSee('foo-order')
    ->call('delete', $order->id)
    ->assertForbidden();          // authorization is testable — test it

Cover: initial render, each action, validation errors, authorization, emitted events (assertDispatched).

Output format

## Livewire design: <page/feature>

### Components
| Component | Owns | Receives | Emits | Lazy? |
|-----------|------|----------|-------|-------|
| …         | …    | …        | …     | …     |

### Wire-vs-Alpine
Alpine handles: … (zero round-trips). Livewire handles: …

### Payload review
Public props: … — locked: …, computed instead of serialized: …

### Round-trip budget
Interaction X: N requests → target M.

Anti-patterns

• ❌ One God-component owning the whole page — every keystroke re-renders everything
• ❌ Two components with writable copies of the same state, synced by hope
• ❌ wire:model.live on every input out of habit (request per keystroke)
• ❌ Fat models in public properties when the view needs three fields
• ❌ Trusting a public property because "the UI doesn't let you change it" — #[Locked] or re-check
• ❌ Livewire round-trip for a dropdown toggle Alpine does for free
• ❌ Skipping authorization in actions because the button was hidden