Method test

/**
 * Method to test an external or internal url for all valid parts.
 *
 * @param   \SimpleXMLElement  $element  The SimpleXMLElement object representing the `<field>` tag for the form field object.
 * @param   mixed              $value    The form field value to validate.
 * @param   string             $group    The field name group control value. This acts as an array container for the field.
 *                                       For example if the field has name="foo" and the group value is set to "bar" then the
 *                                       full field name would end up being "bar[foo]".
 * @param   Registry           $input    An optional Registry object with the entire data set to validate against the entire form.
 * @param   Form               $form     The form object for which the field is being tested.
 *
 * @return  boolean  True if the value is valid, false otherwise.
 *
 * @since   1.7.0
 * @link    https://www.w3.org/Addressing/URL/url-spec.txt
 * @see	    \Joomla\String\StringHelper
 */
public function test(\SimpleXMLElement $element, $value, $group = null, Registry $input = null, Form $form = null)
{
    // If the field is empty and not required, the field is valid.
    $required = (string) $element['required'] === 'true' || (string) $element['required'] === 'required';
    if (!$required && empty($value)) {
        return true;
    }
    $urlParts = UriHelper::parse_url($value);
    // See https://www.w3.org/Addressing/URL/url-spec.txt
    // Use the full list or optionally specify a list of permitted schemes.
    if ($element['schemes'] == '') {
        $scheme = array('http', 'https', 'ftp', 'ftps', 'gopher', 'mailto', 'news', 'prospero', 'telnet', 'rlogin', 'sftp', 'tn3270', 'wais', 'mid', 'cid', 'nntp', 'tel', 'urn', 'ldap', 'file', 'fax', 'modem', 'git');
    } else {
        $scheme = explode(',', $element['schemes']);
    }
    /*
     * Note that parse_url() does not always parse accurately without a scheme,
     * but at least the path should be set always. Note also that parse_url()
     * returns False for seriously malformed URLs instead of an associative array.
     * @link https://www.php.net/manual/en/function.parse-url.php
     */
    if ($urlParts === false || !\array_key_exists('scheme', $urlParts)) {
        /*
         * The function parse_url() returned false (seriously malformed URL) or no scheme
         * was found and the relative option is not set: in both cases the field is not valid.
         */
        if ($urlParts === false || !$element['relative']) {
            $element->addAttribute('message', Text::sprintf('JLIB_FORM_VALIDATE_FIELD_URL_SCHEMA_MISSING', $value, implode(', ', $scheme)));
            return false;
        }
        // The best we can do for the rest is make sure that the path exists and is valid UTF-8.
        if (!\array_key_exists('path', $urlParts) || !StringHelper::valid((string) $urlParts['path'])) {
            return false;
        }
        // The internal URL seems to be good.
        return true;
    }
    // Scheme found, check all parts found.
    $urlScheme = (string) $urlParts['scheme'];
    $urlScheme = strtolower($urlScheme);
    if (\in_array($urlScheme, $scheme) == false) {
        return false;
    }
    // For some schemes here must be two slashes.
    $scheme = array('http', 'https', 'ftp', 'ftps', 'gopher', 'wais', 'prospero', 'sftp', 'telnet', 'git');
    if (\in_array($urlScheme, $scheme) && substr($value, \strlen($urlScheme), 3) !== '://') {
        return false;
    }
    // The best we can do for the rest is make sure that the strings are valid UTF-8
    // and the port is an integer.
    if (\array_key_exists('host', $urlParts) && !StringHelper::valid((string) $urlParts['host'])) {
        return false;
    }
    if (\array_key_exists('port', $urlParts) && !\is_int((int) $urlParts['port'])) {
        return false;
    }
    if (\array_key_exists('path', $urlParts) && !StringHelper::valid((string) $urlParts['path'])) {
        return false;
    }
    return true;
}