JSON to PHP DTO Generator

JSON to PHP DTOs: Structuring Data in Modern PHP

PHP powers a vast majority of the web, and modern PHP frameworks like Laravel and Symfony are increasingly used to build robust REST APIs and microservices. When these applications communicate with external services or frontend SPA applications, they exchange data using JSON. To maintain clean architecture, raw JSON data should be converted into Data Transfer Objects (DTOs) rather than being passed around as associative arrays.

Why Avoid Associative Arrays?

Traditionally, PHP developers would use json_decode($json, true) to parse JSON into an associative array. This approach has critical flaws:

• No Type Safety: You don't know what keys exist or what types their values hold without inspecting the array manually.
• No Autocomplete: IDEs like PhpStorm cannot provide intelligent code completion for dynamic arrays.
• Refactoring Pain: If a third-party API changes a JSON key, you have to search your entire codebase for the hardcoded string key.

The Rise of PHP DTOs and Readonly Classes

A Data Transfer Object (DTO) is a simple class designed to carry data between processes. With PHP 8.1+ introducing readonly properties and PHP 8.2 introducing readonly classes, DTOs have become the standard for handling JSON data safely.

// Input JSON
{
  "transaction_id": "tx_9876",
  "amount": 150.00,
  "currency": "USD"
}

// Generated PHP 8.2+ DTO
readonly class TransactionDto
{
    public function __construct(
        public string $transactionId,
        public float $amount,
        public string $currency,
    ) {}

    public static function fromJson(string $json): self
    {
        $data = json_decode($json, true, 512, JSON_THROW_ON_ERROR);
        return new self(
            transactionId: $data['transaction_id'],
            amount: (float) $data['amount'],
            currency: $data['currency'],
        );
    }
}

Integration with Laravel and Symfony

Generating strict PHP classes from JSON allows you to easily integrate with Laravel's Form Requests or Spatie's Data Transfer Object package. By defining the exact structure of incoming data, you can validate and sanitize requests before they hit your core business logic.

Secure and Local Code Generation

When modeling internal business objects from JSON payloads, privacy is paramount. Pasting your application's JSON structures into online converters means sharing your backend architecture with third parties. TypeMorph runs exclusively in your browser. All PHP DTO generation happens locally, ensuring your data models and API designs remain completely private and secure.