php-expert

PHP Expert

Expert guidance for modern PHP development including PHP 8+ features, Laravel framework, Composer dependency management, and PHP best practices.

Core Concepts

PHP 8+ Features

Union types and mixed type
Named arguments
Attributes (annotations)
Constructor property promotion
Match expressions
Nullsafe operator
JIT compiler
Fibers (PHP 8.1+)
Readonly properties and classes

Object-Oriented PHP

Classes and objects
Interfaces and abstract classes
Traits
Namespaces
Autoloading (PSR-4)
Type declarations
Visibility modifiers

Modern PHP

Strict types
Return type declarations
Property type declarations
Enums (PHP 8.1+)
First-class callable syntax

Modern PHP 8+ Syntax

Constructor Property Promotion

<?php

// Before PHP 8 class User { private string $name; private string $email; private int $age;

public function __construct(string $name, string $email, int $age) {
    $this->name = $name;
    $this->email = $email;
    $this->age = $age;
}

}

// PHP 8+ (constructor property promotion) class User { public function __construct( private string $name, private string $email, private int $age, ) {}

public function getName(): string {
    return $this->name;
}

}

$user = new User('Alice', 'alice@example.com', 30);

Named Arguments

<?php

function createUser( string $name, string $email, int $age = 18, bool $admin = false, ): User { return new User($name, $email, $age, $admin); }

// Named arguments (PHP 8+) $user = createUser( name: 'Alice', email: 'alice@example.com', age: 30, admin: true, );

// Skip optional parameters $user = createUser( name: 'Bob', email: 'bob@example.com', );

Union Types and Mixed

<?php

// Union types (PHP 8+) function processValue(int|float $number): int|float { return $number * 2; }

function findUser(int|string $identifier): ?User { if (is_int($identifier)) { return User::find($identifier); } return User::where('email', $identifier)->first(); }

// Mixed type (accepts any type) function debugValue(mixed $value): void { var_dump($value); }

Match Expression

<?php

// Old switch switch ($status) { case 'pending': $message = 'Order is pending'; break; case 'processing': $message = 'Order is being processed'; break; case 'completed': $message = 'Order completed'; break; default: $message = 'Unknown status'; }

// Match expression (PHP 8+) $message = match ($status) { 'pending' => 'Order is pending', 'processing' => 'Order is being processed', 'completed' => 'Order completed', default => 'Unknown status', };

// Multiple conditions $result = match ($value) { 0, 1, 2 => 'Small', 3, 4, 5 => 'Medium', default => 'Large', };

// With expressions $discount = match (true) { $customer->isPremium() && $order->total() > 1000 => 0.20, $customer->isPremium() => 0.15, $order->total() > 500 => 0.10, default => 0, };

Nullsafe Operator

<?php

// Before PHP 8 $country = null; if ($user !== null) { $address = $user->getAddress(); if ($address !== null) { $country = $address->getCountry(); } }

// PHP 8+ nullsafe operator $country = $user?->getAddress()?->getCountry();

// With default $country = $user?->getAddress()?->getCountry() ?? 'Unknown';

Attributes (Annotations)

<?php

// Define attribute #[Attribute] class Route { public function __construct( public string $path, public string $method = 'GET', ) {} }

// Use attribute class UserController { #[Route('/users', method: 'GET')] public function index(): array { return User::all(); }

#[Route('/users/{id}', method: 'GET')]
public function show(int $id): User {
    return User::findOrFail($id);
}

#[Route('/users', method: 'POST')]
public function store(Request $request): User {
    return User::create($request->all());
}

}

// Read attributes $reflection = new ReflectionClass(UserController::class); foreach ($reflection->getMethods() as $method) { $attributes = $method->getAttributes(Route::class); foreach ($attributes as $attribute) { $route = $attribute->newInstance(); echo "{$route->method} {$route->path}\n"; } }

Enums (PHP 8.1+)

<?php

// Basic enum enum Status { case Pending; case Processing; case Completed; case Cancelled; }

// Usage $status = Status::Pending;

function updateOrder(Order $order, Status $status): void { $order->status = $status; $order->save(); }

// Backed enums enum OrderStatus: string { case Pending = 'pending'; case Processing = 'processing'; case Completed = 'completed'; case Cancelled = 'cancelled';

public function label(): string {
    return match($this) {
        self::Pending => 'Pending',
        self::Processing => 'Being Processed',
        self::Completed => 'Completed',
        self::Cancelled => 'Cancelled',
    };
}

public function color(): string {
    return match($this) {
        self::Pending => 'yellow',
        self::Processing => 'blue',
        self::Completed => 'green',
        self::Cancelled => 'red',
    };
}

}

$status = OrderStatus::from('pending'); echo $status->label(); // 'Pending' echo $status->value; // 'pending'

Readonly Properties and Classes

<?php

// Readonly property (PHP 8.1+) class User { public function __construct( public readonly string $id, public readonly string $email, public string $name, ) {} }

$user = new User('123', 'user@example.com', 'Alice'); $user->name = 'Bob'; // OK // $user->email = 'new@example.com'; // Error: readonly property

// Readonly class (PHP 8.2+) readonly class Point { public function __construct( public int $x, public int $y, ) {} }

Laravel Framework

Models

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model; use Illuminate\Database\Eloquent\Relations\HasMany; use Illuminate\Database\Eloquent\Relations\BelongsToMany; use Illuminate\Database\Eloquent\SoftDeletes;

class User extends Model { use SoftDeletes;

protected $fillable = [
    'name',
    'email',
    'password',
];

protected $hidden = [
    'password',
    'remember_token',
];

protected $casts = [
    'email_verified_at' => 'datetime',
    'is_admin' => 'boolean',
    'settings' => 'array',
];

// Relationships
public function posts(): HasMany
{
    return $this->hasMany(Post::class);
}

public function roles(): BelongsToMany
{
    return $this->belongsToMany(Role::class);
}

// Accessors (Laravel 9+)
protected function name(): Attribute
{
    return Attribute::make(
        get: fn (string $value) => ucfirst($value),
        set: fn (string $value) => strtolower($value),
    );
}

// Scopes
public function scopeActive($query)
{
    return $query->where('active', true);
}

public function scopeAdmins($query)
{
    return $query->where('is_admin', true);
}

// Methods
public function isAdmin(): bool
{
    return $this->is_admin;
}

}

// Usage $users = User::active()->get(); $admins = User::admins()->get(); $user = User::with('posts', 'roles')->find(1);

Controllers

<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller; use App\Http\Requests\StorePostRequest; use App\Http\Requests\UpdatePostRequest; use App\Http\Resources\PostResource; use App\Models\Post; use Illuminate\Http\JsonResponse; use Illuminate\Http\Resources\Json\AnonymousResourceCollection;

class PostController extends Controller { public function __construct() { $this->middleware('auth:api')->except(['index', 'show']); }

public function index(): AnonymousResourceCollection
{
    $posts = Post::with('user')
        ->published()
        ->latest()
        ->paginate(20);

    return PostResource::collection($posts);
}

public function show(Post $post): PostResource
{
    $post->load(['user', 'comments.user']);
    return new PostResource($post);
}

public function store(StorePostRequest $request): JsonResponse
{
    $post = $request->user()->posts()->create(
        $request->validated()
    );

    return response()->json(
        new PostResource($post),
        201
    );
}

public function update(UpdatePostRequest $request, Post $post): PostResource
{
    $this->authorize('update', $post);

    $post->update($request->validated());

    return new PostResource($post);
}

public function destroy(Post $post): JsonResponse
{
    $this->authorize('delete', $post);

    $post->delete();

    return response()->json(null, 204);
}

}

Form Requests

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class StorePostRequest extends FormRequest { public function authorize(): bool { return $this->user() !== null; }

public function rules(): array
{
    return [
        'title' => ['required', 'string', 'max:200'],
        'content' => ['required', 'string', 'min:100'],
        'published' => ['sometimes', 'boolean'],
        'tags' => ['sometimes', 'array'],
        'tags.*' => ['string', 'max:50'],
    ];
}

public function messages(): array
{
    return [
        'title.required' => 'Please provide a title for your post',
        'content.min' => 'Post content must be at least 100 characters',
    ];
}

}

API Resources

<?php

namespace App\Http\Resources;

use Illuminate\Http\Request; use Illuminate\Http\Resources\Json\JsonResource;

class PostResource extends JsonResource { public function toArray(Request $request): array { return [ 'id' => $this->id, 'title' => $this->title, 'slug' => $this->slug, 'content' => $this->when( $request->routeIs('posts.show'), $this->content ), 'excerpt' => $this->excerpt, 'published' => $this->published, 'published_at' => $this->published_at?->toIso8601String(), 'author' => new UserResource($this->whenLoaded('user')), 'comments' => CommentResource::collection( $this->whenLoaded('comments') ), 'tags' => $this->tags, 'created_at' => $this->created_at->toIso8601String(), 'updated_at' => $this->updated_at->toIso8601String(), ]; } }

Eloquent Queries

<?php

// Basic queries $users = User::all(); $user = User::find(1); $user = User::where('email', 'user@example.com')->first();

// Complex queries $posts = Post::where('published', true) ->where('created_at', '>', now()->subWeek()) ->orderBy('created_at', 'desc') ->limit(10) ->get();

// Eager loading (avoid N+1) $posts = Post::with(['user', 'comments.user'])->get();

// Lazy eager loading $posts = Post::all(); $posts->load('user');

// Conditional loading $posts = Post::with([ 'user' => function ($query) { $query->select('id', 'name', 'email'); }, 'comments' => function ($query) { $query->latest()->limit(5); }, ])->get();

// Aggregates $count = Post::where('published', true)->count(); $sum = Order::where('status', 'completed')->sum('total'); $avg = Product::avg('price');

// Chunk processing Post::chunk(100, function ($posts) { foreach ($posts as $post) { // Process post } });

// Transactions DB::transaction(function () use ($data) { $user = User::create($data['user']); $profile = $user->profile()->create($data['profile']); $user->roles()->attach($data['roles']); });

Migrations

<?php

use Illuminate\Database\Migrations\Migration; use Illuminate\Database\Schema\Blueprint; use Illuminate\Support\Facades\Schema;

return new class extends Migration { public function up(): void { Schema::create('posts', function (Blueprint $table) { $table->id(); $table->foreignId('user_id')->constrained()->cascadeOnDelete(); $table->string('title'); $table->string('slug')->unique(); $table->text('content'); $table->text('excerpt')->nullable(); $table->boolean('published')->default(false); $table->timestamp('published_at')->nullable(); $table->json('tags')->nullable(); $table->timestamps(); $table->softDeletes();

        $table->index('published');
        $table->index('published_at');
        $table->index(['user_id', 'published']);
    });
}

public function down(): void
{
    Schema::dropIfExists('posts');
}

};

Jobs (Queues)

<?php

namespace App\Jobs;

use App\Models\User; use Illuminate\Bus\Queueable; use Illuminate\Contracts\Queue\ShouldQueue; use Illuminate\Foundation\Bus\Dispatchable; use Illuminate\Queue\InteractsWithQueue; use Illuminate\Queue\SerializesModels;

class SendWelcomeEmail implements ShouldQueue { use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

public function __construct(
    public User $user,
) {}

public function handle(): void
{
    Mail::to($this->user->email)
        ->send(new WelcomeEmail($this->user));
}

public function failed(\Throwable $exception): void
{
    // Handle job failure
    Log::error('Failed to send welcome email', [
        'user_id' => $this->user->id,
        'error' => $exception->getMessage(),
    ]);
}

}

// Dispatch job SendWelcomeEmail::dispatch($user); SendWelcomeEmail::dispatch($user)->delay(now()->addMinutes(10)); SendWelcomeEmail::dispatch($user)->onQueue('emails');

Events and Listeners

<?php

// Event namespace App\Events;

use App\Models\Post; use Illuminate\Foundation\Events\Dispatchable; use Illuminate\Queue\SerializesModels;

class PostPublished { use Dispatchable, SerializesModels;

public function __construct(
    public Post $post,
) {}

}

// Listener namespace App\Listeners;

use App\Events\PostPublished; use App\Notifications\NewPostNotification;

class NotifyFollowers { public function handle(PostPublished $event): void { $followers = $event->post->user->followers;

    foreach ($followers as $follower) {
        $follower->notify(new NewPostNotification($event->post));
    }
}

}

// Register in EventServiceProvider protected $listen = [ PostPublished::class => [ NotifyFollowers::class, ], ];

// Dispatch event PostPublished::dispatch($post);

Testing with PHPUnit

Feature Tests

<?php

namespace Tests\Feature;

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

class PostControllerTest extends TestCase { use RefreshDatabase;

public function test_can_list_posts(): void
{
    Post::factory()->count(3)->create(['published' => true]);
    Post::factory()->create(['published' => false]);

    $response = $this->getJson('/api/posts');

    $response->assertOk()
        ->assertJsonCount(3, 'data');
}

public function test_can_create_post_when_authenticated(): void
{
    $user = User::factory()->create();

    $response = $this->actingAs($user, 'api')
        ->postJson('/api/posts', [
            'title' => 'Test Post',
            'content' => 'Test content with enough characters to pass validation.',
        ]);

    $response->assertCreated()
        ->assertJsonPath('data.title', 'Test Post');

    $this->assertDatabaseHas('posts', [
        'title' => 'Test Post',
        'user_id' => $user->id,
    ]);
}

public function test_cannot_create_post_when_not_authenticated(): void
{
    $response = $this->postJson('/api/posts', [
        'title' => 'Test Post',
        'content' => 'Test content',
    ]);

    $response->assertUnauthorized();
}

public function test_validates_post_creation(): void
{
    $user = User::factory()->create();

    $response = $this->actingAs($user, 'api')
        ->postJson('/api/posts', [
            'title' => '', // Invalid
            'content' => 'Short', // Too short
        ]);

    $response->assertUnprocessable()
        ->assertJsonValidationErrors(['title', 'content']);
}

public function test_can_update_own_post(): void
{
    $user = User::factory()->create();
    $post = Post::factory()->create(['user_id' => $user->id]);

    $response = $this->actingAs($user, 'api')
        ->putJson("/api/posts/{$post->id}", [
            'title' => 'Updated Title',
            'content' => 'Updated content with enough characters.',
        ]);

    $response->assertOk();
    $this->assertDatabaseHas('posts', [
        'id' => $post->id,
        'title' => 'Updated Title',
    ]);
}

public function test_cannot_update_other_user_post(): void
{
    $user = User::factory()->create();
    $otherUser = User::factory()->create();
    $post = Post::factory()->create(['user_id' => $otherUser->id]);

    $response = $this->actingAs($user, 'api')
        ->putJson("/api/posts/{$post->id}", [
            'title' => 'Updated Title',
        ]);

    $response->assertForbidden();
}

}

Unit Tests

<?php

namespace Tests\Unit;

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

class UserTest extends TestCase { use RefreshDatabase;

public function test_user_has_posts(): void
{
    $user = User::factory()->create();
    $posts = Post::factory()->count(3)->create(['user_id' => $user->id]);

    $this->assertCount(3, $user->posts);
    $this->assertTrue($user->posts->contains($posts->first()));
}

public function test_is_admin_returns_true_for_admin_users(): void
{
    $admin = User::factory()->create(['is_admin' => true]);
    $user = User::factory()->create(['is_admin' => false]);

    $this->assertTrue($admin->isAdmin());
    $this->assertFalse($user->isAdmin());
}

}

Factories

<?php

namespace Database\Factories;

use App\Models\User; use Illuminate\Database\Eloquent\Factories\Factory;

class PostFactory extends Factory { public function definition(): array { return [ 'user_id' => User::factory(), 'title' => fake()->sentence(), 'slug' => fake()->slug(), 'content' => fake()->paragraphs(5, true), 'excerpt' => fake()->paragraph(), 'published' => false, 'published_at' => null, 'tags' => fake()->words(3), ]; }

public function published(): static
{
    return $this->state(fn (array $attributes) => [
        'published' => true,
        'published_at' => now(),
    ]);
}

public function withUser(User $user): static
{
    return $this->state(fn (array $attributes) => [
        'user_id' => $user->id,
    ]);
}

}

Best Practices

Type Safety

<?php declare(strict_types=1);

// Always use strict types // Use type declarations for parameters and return types // Use property types where possible

Dependency Injection

<?php

// Use constructor injection class UserService { public function __construct( private UserRepository $repository, private EventDispatcher $dispatcher, ) {}

public function createUser(array $data): User
{
    $user = $this->repository->create($data);
    $this->dispatcher->dispatch(new UserCreated($user));
    return $user;
}

}

PSR Standards

PSR-1: Basic Coding Standard
PSR-4: Autoloading Standard
PSR-12: Extended Coding Style
PSR-7: HTTP Message Interface

Anti-Patterns to Avoid

❌ Not using strict types: Always declare(strict_types=1) ❌ Fat controllers: Extract logic to services ❌ N+1 queries: Use eager loading ❌ No type declarations: Use types everywhere ❌ Ignoring PSR standards: Follow PSR-4, PSR-12 ❌ Direct DB queries in controllers: Use repositories ❌ Missing validation: Always validate input ❌ No tests: Write tests for critical code

Resources

PHP Documentation: https://www.php.net/docs.php
Laravel Documentation: https://laravel.com/docs
Composer: https://getcomposer.org/
PSR Standards: https://www.php-fig.org/psr/
PHPUnit: https://phpunit.de/

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