A middleware that transforms columns in Laravel-JsonResponses from snake-case to camel-case recursively

readme.txt

This is a Laravel-Middleware that transforms the keys of a JSON-Response coming directly from an Eloquent-Model from snake-case (e.g. user_id) to camel-case (e.g. userId).

The files should be located/created in this locations:

/app/Http/Middleware/CamelCaseJson.php
/routes/api.php
/app/Http/Kernel.php

api.php

<?php

use App\Http\Controllers\MyController;
use Illuminate\Support\Facades\Route;

Route::middleware([
	'auth:sanctum'
])
	->group(function () {
		Route::group(['prefix' => 'myGroupName'], function () {
			Route::get(
				'/api-endpoint-name',
				[MyController::class, 'myControllerFunction']
			)
				->middleware('response.json.camelCaseColumns');
		});
	});

CamelCaseJson.php

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\JsonResponse;
use stdClass;
use Illuminate\Support\Str;

class CamelCaseJson
{
	public static function convertObjectPropertiesToCamelCase($dataItem)
	{
		$newObject = new stdClass();
		foreach ($dataItem as $columnKey => $columnValue) {
			$camelCaseKey = Str::camel($columnKey);
			if (is_object($columnValue)) {
				$newObject->{$camelCaseKey} = CamelCaseJson::convertObjectPropertiesToCamelCase($columnValue);
			} else if (is_array($columnValue)) {
				$newObject->{$camelCaseKey} = CamelCaseJson::convertArrayItemsToCamelCase($columnValue);
			} else {
				$newObject->{$camelCaseKey} = $columnValue;
			}
		}
		return $newObject;
	}

	public static function convertArrayItemsToCamelCase($dataItem)
	{
		$newArray = [];
		foreach ($dataItem as $columnKey => $columnValue) {
			$camelCaseKey = Str::camel($columnKey);
			if (is_object($columnValue)) {
				$newArray[$camelCaseKey] = CamelCaseJson::convertObjectPropertiesToCamelCase($columnValue);
			} else if (is_array($columnValue)) {
				$newArray[$camelCaseKey] = CamelCaseJson::convertArrayItemsToCamelCase($columnValue);
			} else {
				$newArray[$camelCaseKey] = $columnValue;
			}
		}
		return $newArray;
	}

	public function handle($request, Closure $next)
	{
		$response = $next($request);

		if ($response instanceof JsonResponse) {
			$data = $response->getData();
			foreach ($data as $indexKey => $dataItem) {
				$newKey = Str::camel($indexKey);
				if (is_object($dataItem) || is_array($dataItem)) {
					if (is_array($dataItem)) {
						$data->{$newKey} = CamelCaseJson::convertArrayItemsToCamelCase($dataItem);
					} else if (is_object($dataItem)) {
						$data->{$newKey} = CamelCaseJson::convertObjectPropertiesToCamelCase($dataItem);
					}
				} else {
					$data->{$newKey} = $dataItem;
				}
			}
			$response->setData($data);
		}

		return $response;
	}
}

Kernel.php

<?php

namespace App\Http;

use Illuminate\Foundation\Http\Kernel as HttpKernel;

class Kernel extends HttpKernel
{
	// ...
    protected $routeMiddleware = [
       // ...
       'response.json.camelCaseColumns' => \App\Http\Middleware\CamelCaseJson::class
    ]
}