protected function AccountRegistration::compileFormRegex in SMS Framework 8

Same name and namespace in other branches

1. 2.x modules/sms_user/src/AccountRegistration.php \Drupal\sms_user\AccountRegistration::compileFormRegex()
2. 2.1.x modules/sms_user/src/AccountRegistration.php \Drupal\sms_user\AccountRegistration::compileFormRegex()

Compile incoming form configuration to a regular expression.

Parameters

string $form_string: A incoming form configuration message.

string $delimiter: The delimiter to escape, as used by preg_match*().

Return value

string A regular expression.

1 call to AccountRegistration::compileFormRegex()

AccountRegistration::incomingPatternMessage in modules/sms_user/src/AccountRegistration.php

Creates a user if an incoming message contents matches a pattern.

File

modules/sms_user/src/AccountRegistration.php, line 272

Class

AccountRegistration

Defines the account registration service.

Namespace

Drupal\sms_user

Code

protected function compileFormRegex($form_string, $delimiter) {
  $placeholders = [
    'username' => '.+',
    'email' => '\\S+',
    'password' => '.+',
  ];

  // Placeholders enclosed in square brackets and escaped for use in regular
  // expressions. \[user\] , \[email\] etc.
  $regex_placeholders = [];
  foreach (array_keys($placeholders) as $d) {
    $regex_placeholders[] = preg_quote('[' . $d . ']');
  }

  // Split message so placeholders are separated from other text.
  // e.g. for 'U [username] P [password], splits to:
  // 'U ', '[username]', ' P ', '[password]'.
  $regex = '/(' . implode('|', $regex_placeholders) . '+)/';
  $words = preg_split($regex, $form_string, NULL, PREG_SPLIT_DELIM_CAPTURE);

  // Track if a placeholder was used, so subsequent usages create a named back
  // reference. This allows you to use placeholders more than once as a form
  // of confirmation. e.g: 'U [username] P [password] [password]'.
  $placeholder_usage = [];
  $compiled = '';
  foreach ($words as $word) {

    // Remove square brackets from word to determine if it is a placeholder.
    $placeholder = mb_substr($word, 1, -1);

    // Determine if word is a placeholder.
    if (isset($placeholders[$placeholder])) {
      $placeholder_regex = $placeholders[$placeholder];
      if (!in_array($placeholder, $placeholder_usage)) {

        // Convert placeholder to a capture group.
        $compiled .= '(?<' . $placeholder . '>' . $placeholder_regex . ')';
        $placeholder_usage[] = $placeholder;
      }
      else {

        // Create a back reference to the previous named capture group.
        $compiled .= '\\k{' . $placeholder . '}';
      }
    }
    else {

      // Text is not a placeholder, do not convert to a capture group.
      $compiled .= preg_quote($word, $delimiter);
    }
  }
  return $compiled;
}