GUMP::sanitize PHP Method

    public function sanitize(array $input, array $fields = array(), $utf8_encode = true)
    {
        $magic_quotes = (bool) get_magic_quotes_gpc();
        if (empty($fields)) {
            $fields = array_keys($input);
        }
        $return = array();
        foreach ($fields as $field) {
            if (!isset($input[$field])) {
                continue;
            } else {
                $value = $input[$field];
                if (is_array($value)) {
                    $value = sanitize($value);
                }
                if (is_string($value)) {
                    if ($magic_quotes === true) {
                        $value = stripslashes($value);
                    }
                    if (strpos($value, "\r") !== false) {
                        $value = trim($value);
                    }
                    if (function_exists('iconv') && function_exists('mb_detect_encoding') && $utf8_encode) {
                        $current_encoding = mb_detect_encoding($value);
                        if ($current_encoding != 'UTF-8' && $current_encoding != 'UTF-16') {
                            $value = iconv($current_encoding, 'UTF-8', $value);
                        }
                    }
                    $value = filter_var($value, FILTER_SANITIZE_STRING);
                }
                $return[$field] = $value;
            }
        }
        return $return;
    }

	/**
	 *
	 *	Processes the request from the user
	 *	The main engine of the class
	 *
	 * 	@param object $post WP_Post Object
	 * 	returns nothing
	 *
	 */

	function process_article()
	{
		require_once CPT_PLUGIN_DIR . 'assets/php/gump/gump.class.php';

		$gump = new GUMP();

		$_POST = $gump->sanitize($_POST); // You don't have to sanitize, but it's safest to do so.

		$gump->validation_rules(array(
		    'email'       => 'required|valid_email',
		));

		$gump->filter_rules(array(
		    'email'    => 'trim|sanitize_email',
		));

		$validated_data = $gump->run($_POST);

		if($validated_data === false) {
			$this->message_type = 'error';
		    $this->message = $gump->get_readable_errors(true);
		} else {

			// Get the article data
			$this->post = get_post($validated_data['post_id'], OBJECT, 'edit');

			//build the html
			$email_html = $this->build_html();

			// If article is sent
			if($this->send_email($validated_data['email']))
			{
				$this->message_type = 'success';
			    $this->message = 'The article link has been emailed';
			}
			else
			{
				$this->message_type = 'error';
			    $this->message = 'The article has not been sent. Please try again';
			}
		}

		// Finally send the response to user
		$this->response_message();

	}