kreativan/reCaptcha-Ajax-Submit.js

## reCaptcha-Ajax-Submit.js
const formSubmitRecapcha = function (site_key = "") {
  grecaptcha.ready(function () {
    grecaptcha.execute(site_key, {
      action: 'contact'
    }).then(function (token) {
      // Get #recaptchaResponse field and populate it's value
      var recaptchaResponse = document.getElementById('recaptchaResponse');
      recaptchaResponse.value = token;
      //
      // Make the Ajax Call
      //
  });
});

## reCaptcha-Form-Example.php
<?php
Use Kreativan\Recapcha;
?>

<form action="./" method="POST" enctype='multipart/form-data'>

  <?php
    echo Recapcha::input();
  ?>

  <button type="button" onclick="formSubmitRecapcha('<?= Recapcha::get_site_key() ?>')">
    Submit
  </button>

</form>

## reCaptcha-Validation.php
<?php

use Kreativan\Recapcha;

/**
 * Check for reCapcha
 * if there is recaptcha_response in POST, validate it
 */
if (isset($_POST['recaptcha_response'])) {
  $recapcha = Recapcha::is_valid();
  if (!$recapcha) {
    $response["status"] = "error";
    $response["errors"][] = "Recapcha validation failed";
    response($response);
    exit();
  }
}

## reCaptcha.php
<?php

/**
 * Recapcha Class
 * Handle recaptcha validation using $_POST['recaptcha_response'] request.
 *
 * You need to have "recaptcha_response" field in your form,
 * and populate it's value dynamically just before or during the form submit.
 *
 * Set site_key and secret_key
 * Recapcha::set_site_key('YOUR_CUSTOM_SITE_KEY');
 * Recapcha::set_secret_key('YOUR_CUSTOM_SECRET_KEY');
 *
 * Render script in <head>
 * @example echo Recapcha::script();
 *
 * Render input field inside form
 * @example echo Recapcha::input();
 *
 * Validate - will return bool true/false
 * @example $recapcha = Recapcha::is_valid();
 */

namespace Kreativan;

class Recapcha {

  private static $site_key = '';
  private static $secret_key = '';

  /**
   * GET
   */

  public static function get_site_key() {
    return self::$site_key;
  }

  public static function get_secret_key() {
    return self::$secret_key;
  }

  /**
   * SET
   */

  public static function set_site_key($value) {
    self::$site_key = $value;
  }

  public static function set_secret_key($value) {
    self::$secret_key = $value;
  }

  public static function input() {
    return '<input type="hidden" name="recaptcha_response" id="recaptchaResponse">';
  }

  /**
   * Render google recaptcha script
   *
   * @example in <head> section of your website
   * echo Kreativan\Recapcha::script();
   */
  public static function script() {
    return '<script async src="https://www.google.com/recaptcha/api.js?render=' . self::get_site_key() . '"></script>';
  }

  /**
   * Check if recaptcha is valid

   * @see @method self::validate()
   */
  public static function is_valid() {
    $validation_response = self::validate();
    return $validation_response['success'];
  }

  /**
   * Server side recapcha validation
   * Send POST req to the google end-point with 'recaptcha_response'.
   * End point will return json with 'success' key true/false
   */
  public static function validate() {
    $recaptcha_url = 'https://www.google.com/recaptcha/api/siteverify';
    $recaptcha_secret = self::secret_key();
    $recaptcha_response = $_POST['recaptcha_response'];
    // Make the POST request
    $recaptcha = file_get_contents($recaptcha_url . '?secret=' . $recaptcha_secret . '&response=' . $recaptcha_response);
    return json_decode($recaptcha, true);
  }
}
	const formSubmitRecapcha = function (site_key = "") {
	grecaptcha.ready(function () {
	grecaptcha.execute(site_key, {
	action: 'contact'
	}).then(function (token) {
	// Get #recaptchaResponse field and populate it's value
	var recaptchaResponse = document.getElementById('recaptchaResponse');
	recaptchaResponse.value = token;
	//
	// Make the Ajax Call
	//
	});
	});
	<?php
	Use Kreativan\Recapcha;
	?>

	<form action="./" method="POST" enctype='multipart/form-data'>

	<?php
	echo Recapcha::input();
	?>

	<button type="button" onclick="formSubmitRecapcha('<?= Recapcha::get_site_key() ?>')">
	Submit
	</button>

	</form>
	<?php

	use Kreativan\Recapcha;

	/**
	* Check for reCapcha
	* if there is recaptcha_response in POST, validate it
	*/
	if (isset($_POST['recaptcha_response'])) {
	$recapcha = Recapcha::is_valid();
	if (!$recapcha) {
	$response["status"] = "error";
	$response["errors"][] = "Recapcha validation failed";
	response($response);
	exit();
	}
	}
	<?php

	/**
	* Recapcha Class
	* Handle recaptcha validation using $_POST['recaptcha_response'] request.
	*
	* You need to have "recaptcha_response" field in your form,
	* and populate it's value dynamically just before or during the form submit.
	*
	* Set site_key and secret_key
	* Recapcha::set_site_key('YOUR_CUSTOM_SITE_KEY');
	* Recapcha::set_secret_key('YOUR_CUSTOM_SECRET_KEY');
	*
	* Render script in <head>
	* @example echo Recapcha::script();
	*
	* Render input field inside form
	* @example echo Recapcha::input();
	*
	* Validate - will return bool true/false
	* @example $recapcha = Recapcha::is_valid();
	*/

	namespace Kreativan;

	class Recapcha {

	private static $site_key = '';
	private static $secret_key = '';

	/**
	* GET
	*/

	public static function get_site_key() {
	return self::$site_key;
	}

	public static function get_secret_key() {
	return self::$secret_key;
	}

	/**
	* SET
	*/

	public static function set_site_key($value) {
	self::$site_key = $value;
	}

	public static function set_secret_key($value) {
	self::$secret_key = $value;
	}

	public static function input() {
	return '<input type="hidden" name="recaptcha_response" id="recaptchaResponse">';
	}

	/**
	* Render google recaptcha script
	*
	* @example in <head> section of your website
	* echo Kreativan\Recapcha::script();
	*/
	public static function script() {
	return '<script async src="https://www.google.com/recaptcha/api.js?render=' . self::get_site_key() . '"></script>';
	}

	/**
	* Check if recaptcha is valid

	* @see @method self::validate()
	*/
	public static function is_valid() {
	$validation_response = self::validate();
	return $validation_response['success'];
	}

	/**
	* Server side recapcha validation
	* Send POST req to the google end-point with 'recaptcha_response'.
	* End point will return json with 'success' key true/false
	*/
	public static function validate() {
	$recaptcha_url = 'https://www.google.com/recaptcha/api/siteverify';
	$recaptcha_secret = self::secret_key();
	$recaptcha_response = $_POST['recaptcha_response'];
	// Make the POST request
	$recaptcha = file_get_contents($recaptcha_url . '?secret=' . $recaptcha_secret . '&response=' . $recaptcha_response);
	return json_decode($recaptcha, true);
	}
	}