ReCAPTCHA 2 Error Code Parsing

recaptchalib-errors.php

<?php

/**
 * Parse ReCAPTCHA API verion 2.0 error codes.
 *
 * @uses   mcaskill\ReCAPTCHA or jmcastagnetto\ReCAPTCHA
 * @link   https://developers.google.com/recaptcha/docs/verify  Error code reference
 *
 * @param  mixed  $response  A Google\ReCaptcha\Response or null
 * @param  array  $arr       If the second parameter $arr is present, error messages are stored in this variable as associative array elements instead.
 * @return array  $arr
 */

function parse_recaptcha_response_errors( $response = null, & $arr = array() )
{
	$_error_message = 'An unknown error or malformed response has occured.');
	$_error_code    = 'unknown-error-response';

	if ( ! isset( $response->errorCodes ) ) {
		$arr[ $_error_code ] = $_error_message;

		return $arr;
	}

	$codes = $response->errorCodes;

	if ( ! is_array( $codes ) ) {
		$codes = [ $codes ];
	}

	$codes = array_filter( $codes, 'strlen' );

	if ( ! count( $codes ) ) {
		$arr[ $_error_code ] = $_error_message;

		return $arr;
	}

	foreach ( $codes as $code ) {

		switch ( $code ) {

			case 'missing-input-secret':
				$arr[ $code ] = 'The secret parameter is missing.';
				break;

			case 'invalid-input-secret':
				$arr[ $code ] = 'The secret parameter is invalid or malformed.';
				break;

			case 'missing-input':
			case 'missing-input-response':
				$arr[ $code ] = 'The response parameter is missing.';
				break;

			case 'invalid-input':
			case 'invalid-input-response':
				$arr[ $code ] = 'The response parameter is invalid or malformed.';
				break;

			default:
				$arr[ $code ] = $_error_message;
				break;
		}

	}

	return $arr;
}