jgauthi/hCaptcha.php

## hCaptcha.php
<?php
use Symfony\Component\HttpClient\HttpClient;
use Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface;

// Complete configuration: https://hcaptcha.com
const HCAPTCHA_SECRET_KEY = '...';
const HCAPTCHA_API_KEY = '...';

/**
 * @throws Exception
 * @throws TransportExceptionInterface
 * @throws \Symfony\Contracts\HttpClient\Exception\ClientExceptionInterface
 * @throws \Symfony\Contracts\HttpClient\Exception\DecodingExceptionInterface
 * @throws \Symfony\Contracts\HttpClient\Exception\RedirectionExceptionInterface
 * @throws \Symfony\Contracts\HttpClient\Exception\ServerExceptionInterface
 */
function checkForm(array $postData): ?bool
{
    if (!empty($postData['email'])
        && filter_var($postData['email'], FILTER_VALIDATE_EMAIL)
    ) {
        // https://docs.hcaptcha.com/
        if (!empty(HCAPTCHA_SECRET_KEY) && !empty(HCAPTCHA_API_KEY)) {
            if (empty($_POST['h-captcha-response'])) {
                throw new InvalidArgumentException('Captcha empty, have you completed this test ?');
            }

            $client = HttpClient::create();
            $response = $client->request( 'POST', 'https://hcaptcha.com/siteverify', [
                'body' => [
                    'secret'   => HCAPTCHA_SECRET_KEY,
                    'sitekey'  => HCAPTCHA_API_KEY,
                    'response' => $_POST['h-captcha-response'],
                    'remoteip' => $_SERVER['REMOTE_ADDR'],
                ],
            ] );

            $return = $response->toArray();
            if (!isset($return['success']) || !$return['success']) {
                $error = !empty($return['error-codes'])
                    ? 'Error codes: '.implode(', ', $return['error-codes'])
                    : 'No code returned by the API';

                throw new Exception($error);
            }
        }

        // form check [...]
        return true;
    }

    return null;
}

?><html>
<head>
    <title>hCaptcha Demo</title>
    <script src="https://hcaptcha.com/1/api.js" async defer></script>
</head>
<body>
<?php
if ('POST' == $_SERVER['REQUEST_METHOD']) {
    try {
        if ( checkForm($_POST) ) {
            echo '<p>OK.</p>';
        } else {
            echo '<p>Error during form validation.</p>';
        }

    } catch ( Throwable $exception ) {
        ?>
        <p>Error during form validation: <?=$exception->getMessage()?></p>
        <?php
    }
} else {
    ?><form action="<?=$_SERVER['REQUEST_URI']?>" method="POST">
    <input type="text" name="email" placeholder="Email" />

    <?php if (!empty(HCAPTCHA_SECRET_KEY) && !empty(HCAPTCHA_API_KEY)): ?>
        <div class="h-captcha" data-sitekey="<?=HCAPTCHA_API_KEY?>"></div>
    <?php endif ?>

    <br />
    <input type="submit" value="Submit" />
    </form>
<?php } ?>

</body>
</html>
	<?php
	use Symfony\Component\HttpClient\HttpClient;
	use Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface;

	// Complete configuration: https://hcaptcha.com
	const HCAPTCHA_SECRET_KEY = '...';
	const HCAPTCHA_API_KEY = '...';

	/**
	* @throws Exception
	* @throws TransportExceptionInterface
	* @throws \Symfony\Contracts\HttpClient\Exception\ClientExceptionInterface
	* @throws \Symfony\Contracts\HttpClient\Exception\DecodingExceptionInterface
	* @throws \Symfony\Contracts\HttpClient\Exception\RedirectionExceptionInterface
	* @throws \Symfony\Contracts\HttpClient\Exception\ServerExceptionInterface
	*/
	function checkForm(array $postData): ?bool
	{
	if (!empty($postData['email'])
	&& filter_var($postData['email'], FILTER_VALIDATE_EMAIL)
	) {
	// https://docs.hcaptcha.com/
	if (!empty(HCAPTCHA_SECRET_KEY) && !empty(HCAPTCHA_API_KEY)) {
	if (empty($_POST['h-captcha-response'])) {
	throw new InvalidArgumentException('Captcha empty, have you completed this test ?');
	}

	$client = HttpClient::create();
	$response = $client->request( 'POST', 'https://hcaptcha.com/siteverify', [
	'body' => [
	'secret' => HCAPTCHA_SECRET_KEY,
	'sitekey' => HCAPTCHA_API_KEY,
	'response' => $_POST['h-captcha-response'],
	'remoteip' => $_SERVER['REMOTE_ADDR'],
	],
	] );

	$return = $response->toArray();
	if (!isset($return['success']) \|\| !$return['success']) {
	$error = !empty($return['error-codes'])
	? 'Error codes: '.implode(', ', $return['error-codes'])
	: 'No code returned by the API';

	throw new Exception($error);
	}
	}

	// form check [...]
	return true;
	}

	return null;
	}

	?><html>
	<head>
	<title>hCaptcha Demo</title>
	<script src="https://hcaptcha.com/1/api.js" async defer></script>
	</head>
	<body>
	<?php
	if ('POST' == $_SERVER['REQUEST_METHOD']) {
	try {
	if ( checkForm($_POST) ) {
	echo '<p>OK.</p>';
	} else {
	echo '<p>Error during form validation.</p>';
	}

	} catch ( Throwable $exception ) {
	?>
	<p>Error during form validation: <?=$exception->getMessage()?></p>
	<?php
	}
	} else {
	?><form action="<?=$_SERVER['REQUEST_URI']?>" method="POST">
	<input type="text" name="email" placeholder="Email" />

	<?php if (!empty(HCAPTCHA_SECRET_KEY) && !empty(HCAPTCHA_API_KEY)): ?>
	<div class="h-captcha" data-sitekey="<?=HCAPTCHA_API_KEY?>"></div>
	<?php endif ?>

	<br />
	<input type="submit" value="Submit" />
	</form>
	<?php } ?>

	</body>
	</html>