Laravel Livewire 3 ในปี 2026: สร้างแอปพลิเคชัน Reactive และคำถามสัมภาษณ์งาน

<?php

namespace App\Livewire;

use App\Models\User;
use Livewire\Component;
use Livewire\WithPagination;
use Livewire\Attributes\Url;

class SearchUsers extends Component
{
    use WithPagination;

    #[Url] // ซิงค์ property กับ URL query string
    public string $search = '';

    #[Url]
    public string $role = '';

    public function updatedSearch(): void
    {
        // รีเซ็ต pagination เมื่อการค้นหาเปลี่ยน
        $this->resetPage();
    }

    public function render()
    {
        return view('livewire.search-users', [
            'users' => User::query()
                ->when($this->search, fn($q) => $q->where('name', 'like', "%{$this->search}%"))
                ->when($this->role, fn($q) => $q->where('role', $this->role))
                ->paginate(10),
        ]);
    }
}

<?php

namespace App\Livewire;

use App\Models\Post;
use Livewire\Component;
use Livewire\Attributes\Rule;
use Livewire\Attributes\Locked;
use Livewire\Attributes\Computed;

class CreatePost extends Component
{
    #[Locked] // ไม่สามารถแก้ไขจาก frontend ได้
    public int $userId;

    #[Rule('required|min:5|max:200')]
    public string $title = '';

    #[Rule('required|min:50')]
    public string $content = '';

    #[Rule('nullable|array')]
    public array $tags = [];

    public function mount(): void
    {
        $this->userId = auth()->id();
    }

    #[Computed]
    public function wordCount(): int
    {
        return str_word_count($this->content);
    }

    public function save(): void
    {
        $validated = $this->validate();

        Post::create([
            'user_id' => $this->userId,
            ...$validated,
        ]);

        $this->reset(['title', 'content', 'tags']);
        $this->dispatch('post-created');
    }

    public function render()
    {
        return view('livewire.create-post');
    }
}

<?php

namespace App\Livewire;

use App\Models\User;
use Livewire\Component;
use Livewire\Attributes\Rule;
use Livewire\Attributes\Validate;
use Illuminate\Validation\Rules\Password;

class RegistrationForm extends Component
{
    #[Rule('required|email|unique:users,email')]
    public string $email = '';

    #[Rule('required|min:2|max:50')]
    public string $name = '';

    public string $password = '';
    public string $passwordConfirmation = '';

    public function rules(): array
    {
        return [
            'password' => [
                'required',
                'confirmed',
                Password::min(8)->mixedCase()->numbers(),
            ],
        ];
    }

    public function updated(string $property): void
    {
        // Validate property เดี่ยวเมื่อมีการเปลี่ยนแปลง
        $this->validateOnly($property);
    }

    public function register(): void
    {
        $validated = $this->validate();

        $user = User::create([
            'email' => $validated['email'],
            'name' => $validated['name'],
            'password' => bcrypt($validated['password']),
        ]);

        auth()->login($user);
        $this->redirect('/dashboard');
    }

    public function render()
    {
        return view('livewire.registration-form');
    }
}

{{-- resources/views/livewire/registration-form.blade.php --}}
<form wire:submit="register" class="space-y-4">
    <div>
        <label for="email" class="block text-sm font-medium">อีเมล</label>
        <input 
            wire:model.blur="email" 
            type="email" 
            id="email"
            class="mt-1 block w-full rounded-md border-gray-300"
        >
        @error('email')
            <p class="mt-1 text-sm text-red-600">{{ $message }}</p>
        @enderror
    </div>

    <div>
        <label for="password" class="block text-sm font-medium">รหัสผ่าน</label>
        <input 
            wire:model.blur="password" 
            type="password" 
            id="password"
            class="mt-1 block w-full rounded-md border-gray-300"
        >
        @error('password')
            <p class="mt-1 text-sm text-red-600">{{ $message }}</p>
        @enderror
    </div>

    <div>
        <label for="passwordConfirmation" class="block text-sm font-medium">ยืนยันรหัสผ่าน</label>
        <input 
            wire:model.blur="passwordConfirmation" 
            type="password" 
            id="passwordConfirmation"
            class="mt-1 block w-full rounded-md border-gray-300"
        >
    </div>

    <button 
        type="submit" 
        class="w-full bg-indigo-600 text-white py-2 px-4 rounded-md"
        wire:loading.attr="disabled"
    >
        <span wire:loading.remove>ลงทะเบียน</span>
        <span wire:loading>กำลังดำเนินการ...</span>
    </button>
</form>

<?php

namespace App\Livewire;

use App\Models\Task;
use Livewire\Component;
use Livewire\Attributes\On;

class TaskBoard extends Component
{
    public array $columns = ['todo', 'in_progress', 'done'];

    #[On('task-moved')]
    public function handleTaskMoved(int $taskId, string $newStatus): void
    {
        Task::where('id', $taskId)->update(['status' => $newStatus]);
    }

    #[On('task-created')]
    public function refreshBoard(): void
    {
        // Component จะ render ใหม่โดยอัตโนมัติ
    }

    public function render()
    {
        return view('livewire.task-board', [
            'tasks' => Task::all()->groupBy('status'),
        ]);
    }
}

<?php

namespace App\Livewire;

use App\Models\Task;
use Livewire\Component;

class TaskCard extends Component
{
    public Task $task;

    public function moveToStatus(string $status): void
    {
        $this->dispatch('task-moved', taskId: $this->task->id, newStatus: $status);
    }

    public function render()
    {
        return view('livewire.task-card');
    }
}

{{-- resources/views/livewire/notification-dropdown.blade.php --}}
<div 
    x-data="{ 
        open: false,
        unreadCount: @entangle('unreadCount')
    }"
    class="relative"
>
    <button @click="open = !open" class="relative p-2">
        <svg class="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" 
                  d="M15 17h5l-1.405-1.405A2.032 2.032 0 0118 14.158V11a6 6 0 10-12 0v3.159c0 .538-.214 1.055-.595 1.436L4 17h5m6 0v1a3 3 0 11-6 0v-1m6 0H9" />
        </svg>
        <span 
            x-show="unreadCount > 0"
            x-text="unreadCount"
            class="absolute -top-1 -right-1 bg-red-500 text-white text-xs rounded-full w-5 h-5 flex items-center justify-center"
        ></span>
    </button>

    <div 
        x-show="open" 
        @click.outside="open = false"
        x-transition
        class="absolute right-0 mt-2 w-80 bg-white rounded-lg shadow-lg"
    >
        @foreach($notifications as $notification)
            <div 
                wire:click="markAsRead({{ $notification->id }})"
                class="p-4 border-b hover:bg-gray-50 cursor-pointer"
            >
                <p class="font-medium">{{ $notification->title }}</p>
                <p class="text-sm text-gray-600">{{ $notification->message }}</p>
            </div>
        @endforeach
    </div>
</div>

<?php

namespace App\Livewire;

use Livewire\Component;
use Livewire\WithFileUploads;
use Livewire\Attributes\Rule;
use Illuminate\Support\Facades\Storage;

class DocumentUploader extends Component
{
    use WithFileUploads;

    #[Rule('required|file|mimes:pdf,docx|max:10240')] // สูงสุด 10MB
    public $document;

    public ?string $uploadedPath = null;

    public function updatedDocument(): void
    {
        $this->validate();
    }

    public function save(): void
    {
        $this->validate();

        $this->uploadedPath = $this->document->store('documents', 'public');

        $this->dispatch('document-uploaded', path: $this->uploadedPath);
        $this->reset('document');
    }

    public function render()
    {
        return view('livewire.document-uploader');
    }
}

{{-- resources/views/livewire/document-uploader.blade.php --}}
<div class="space-y-4">
    <div 
        x-data="{ uploading: false, progress: 0 }"
        x-on:livewire-upload-start="uploading = true"
        x-on:livewire-upload-finish="uploading = false; progress = 0"
        x-on:livewire-upload-error="uploading = false"
        x-on:livewire-upload-progress="progress = $event.detail.progress"
    >
        <input 
            type="file" 
            wire:model="document"
            accept=".pdf,.docx"
            class="block w-full text-sm text-gray-500 file:mr-4 file:py-2 file:px-4 file:rounded-md file:border-0 file:bg-indigo-50 file:text-indigo-700"
        >

        <div x-show="uploading" class="mt-2">
            <div class="bg-gray-200 rounded-full h-2">
                <div 
                    class="bg-indigo-600 h-2 rounded-full transition-all duration-300"
                    :style="'width: ' + progress + '%'"
                ></div>
            </div>
            <p class="text-sm text-gray-600 mt-1" x-text="'กำลังอัปโหลด: ' + progress + '%'"></p>
        </div>
    </div>

    @error('document')
        <p class="text-sm text-red-600">{{ $message }}</p>
    @enderror

    @if($document)
        <div class="flex items-center justify-between p-3 bg-gray-50 rounded-lg">
            <span class="text-sm">{{ $document->getClientOriginalName() }}</span>
            <button wire:click="save" class="bg-indigo-600 text-white px-4 py-2 rounded-md text-sm">
                อัปโหลด
            </button>
        </div>
    @endif
</div>

<?php

namespace Tests\Feature\Livewire;

use App\Livewire\SearchUsers;
use App\Models\User;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Livewire\Livewire;
use Tests\TestCase;

class SearchUsersTest extends TestCase
{
    use RefreshDatabase;

    public function test_can_search_users_by_name(): void
    {
        User::factory()->create(['name' => 'John Doe', 'role' => 'admin']);
        User::factory()->create(['name' => 'Jane Smith', 'role' => 'user']);

        Livewire::test(SearchUsers::class)
            ->set('search', 'John')
            ->assertSee('John Doe')
            ->assertDontSee('Jane Smith');
    }

    public function test_can_filter_by_role(): void
    {
        User::factory()->create(['name' => 'Admin User', 'role' => 'admin']);
        User::factory()->create(['name' => 'Regular User', 'role' => 'user']);

        Livewire::test(SearchUsers::class)
            ->set('role', 'admin')
            ->assertSee('Admin User')
            ->assertDontSee('Regular User');
    }

    public function test_pagination_resets_on_search_change(): void
    {
        User::factory()->count(25)->create();

        Livewire::test(SearchUsers::class)
            ->call('gotoPage', 2)
            ->assertSet('paginators.page', 2)
            ->set('search', 'test')
            ->assertSet('paginators.page', 1);
    }

    public function test_url_reflects_search_parameters(): void
    {
        Livewire::withQueryParams(['search' => 'existing'])
            ->test(SearchUsers::class)
            ->assertSet('search', 'existing');
    }
}