spamspan.module in SpamSpan filter 5

This module implements the spamspan technique (http://www.spamspan.com ) for hiding email addresses from spambots. If javascript is disabled on the client-side, addresses appear as example [at] example [dot] com.

(c) 2006 - 2007 Lawrence Akka

Licenced under GPL v 2 - see http://www.gnu.org/licenses/gpl.txt

File

spamspan.module

<?php

/**
 * @file This module implements the spamspan technique
 * (http://www.spamspan.com ) for hiding email addresses from spambots.
 * If javascript is disabled on the client-side, addresses appear as
 * example [at] example [dot] com.
 *
 * (c) 2006 - 2007 Lawrence Akka
 *
 * Licenced under GPL v 2 -  see http://www.gnu.org/licenses/gpl.txt
 */

/**
 * Implementation of hook_help().
 */
function spamspan_help($section) {
  switch ($section) {
    case 'admin/modules#description':

      // This description is shown in the listing at admin/modules.
      $output = t('Disguises email addresses in an attempt to reduce spam.');
      if (module_exists('spamspan')) {
        $output .= t(' <a href="%url">more help</a>', array(
          '%url' => url('admin/help/spamspan'),
        ));
      }
      return $output;
    case 'admin/help#spamspan':
      return t('<p>The SpamSpan module obfuscates email addresses to help prevent spambots from collecting them. It will produce clickable links if JavaScript is enabled, and will show the email address as <code>example [at] example [dot] com</code> if the browser does not support JavaScript.</p><p>To configure the module, select "configure" next to the <a href="%url">input format</a> you\'d like to use. Enable "Hide Email Addresses" and submit the form. Then select the "configure" tab to choose relevant options.</p>', array(
        '%url' => url('admin/filters'),
      ));
  }
}

/**
 * Implementation of hook_filter_tips().
 *
 */
function spamspan_filter_tips($delta, $format, $long = FALSE) {
  switch ($delta) {
    case 0:
      return t('Each email address will be obfuscated in a human readble fashion or (if JavaScript is enabled) replaced with a spamproof clickable link.');
      break;
  }
}

/**
 * Implementation of hook_filter().
 *
 */
function spamspan_filter($op, $delta = 0, $format = -1, $text = '') {
  if ($op == 'list') {
    return array(
      0 => t('Hide email addresses'),
    );
  }
  switch ($delta) {
    case 0:
      switch ($op) {
        case 'description':
          return t('Attempt to hide email addresses from spam-bots.');
        case 'prepare':
          return $text;
        case 'process':
          return spamspan(spamspan_convertmailto($text));
        case 'settings':

          // field set for the spamspan settings
          $form['spamspan_settings'] = array(
            '#type' => 'fieldset',
            '#title' => t('SpamSpan email address encoding filter'),
            '#description' => t('Warning: these are global settings and not per input format. Changing them here will change them for other input formats too.'),
            '#collapsible' => true,
          );

          // spamspan user name part class name
          $form['spamspan_settings']['spamspan_userclass'] = array(
            '#type' => 'textfield',
            '#title' => t('User name class'),
            '#default_value' => variable_get('spamspan_userclass', 'u'),
            '#required' => TRUE,
            '#description' => t('The class name of the &lt;span&gt; element enclosing the part of the address before the "@".'),
          );

          // spamspan domain part class name
          $form['spamspan_settings']['spamspan_domainclass'] = array(
            '#type' => 'textfield',
            '#title' => t('Domain part class'),
            '#default_value' => variable_get('spamspan_domainclass', 'd'),
            '#required' => TRUE,
            '#description' => t('The class name of the &lt;span&gt; element enclosing the part of the address after the "@".'),
          );

          // spamspan '@' replacement
          $form['spamspan_settings']['spamspan_at'] = array(
            '#type' => 'textfield',
            '#title' => t('Replacement for "@"'),
            '#default_value' => variable_get('spamspan_at', ' [at] '),
            '#required' => TRUE,
            '#description' => t('Replace "@" with this text when javascript is disabled.'),
          );
          return $form;
      }
      break;
  }
}

/**
 * Implementation of hook_footer().
 */
function spamspan_footer($main = 0) {

  // Add the javascript to each page
  drupal_add_js(drupal_get_path("module", "spamspan") . '/spamspan.compressed.js');

  // pass necessary variables to the javascript
  drupal_add_js(array(
    'spamspan' => array(
      'm' => 'spamspan',
      'u' => variable_get('spamspan_userclass', 'u'),
      'd' => variable_get('spamspan_domainclass', 'd'),
      't' => variable_get('spamspan_anchorclass', 't'),
    ),
  ), 'setting');
}

/**
 * callback function for preg_replace_callback
 */
function spamspan_callback($matches) {

  // Replace .'s in the address with [dot]
  $user_name = str_replace(".", " [dot] ", $matches[1]);
  $domain = str_replace(".", " [dot] ", $matches[2]);
  return '<span class="spamspan"><span class="' . variable_get('spamspan_userclass', 'u') . "\">{$user_name}</span>" . variable_get('spamspan_at', ' [at] ') . "<span class=\"" . variable_get('spamspan_domainclass', 'd') . "\">{$domain}</span></span>";
}

/**
 * Central SpamSpan replace function
 * We are aiming for code like this:
 *   <span class="spamspan">
 *   <span class="u">user</span>
 *   [at]
 *   <span class="d">example [dot] com</span>
 *   </span>
 */
function spamspan($string) {

  // The following pattern is not perfect (who is?), but is intended to intercept
  // things which look like email addresses.  It is not intended to determine if
  // an address is valid.  It will not intercept addresses with quoted local parts
  $pattern = "!\n    ##################################################\n    # Group 1\n      ([-\\.\\~\\'\\w\\+^@]+)    # Match the name part - dash, dot or characters\n      @                     # @\n    # Group 2\n      ((?:\n        [-\\w]+\\.            # one or more letters or dashes followed by a dot\n        )+                  # The whole thing one or more times\n        [A-Z]{2,6}          # with between two and six letters at the end (NB .museum)\n      )\n    ###################################################\n    !ix";

  // Case insensitive, ignore whitespace
  return preg_replace_callback($pattern, 'spamspan_callback', $string);
}
function spamspan_convertmailto($string = '') {

  // does not presently work with URL parameters, eg
  // mailto:[e-mail]?subject=subject
  define("REGEX", "!<a\\s+  # opening <a and spaces\n      (?:(?:\\w+\\s*=\\s*)(?:\\w+|\"[^\"]*\"|'[^']*'))*?      # any attributes\n      \\s*                                                 # whitespace\n      href\\s*=\\s*(['\"])mailto:(.+?)\\1                   # the href attribute, capturing the value\n      (?:(?:\\s+\\w+\\s*=\\s*)(?:\\w+|\"[^\"]*\"|'[^']*'))*?   # any more attributes\n      >                                                   # end of the first tag\n      .*?                                                 # tag contents.  NB this will not work properly if there\n                                                          # is a nested <a>, but this is not valid xhtml anyway\n      </a>                                                # closing tag\n      !ix");
  return preg_replace(REGEX, "\\2", $string);
}

Functions

Name	Description
spamspan	Central SpamSpan replace function We are aiming for code like this: <span class="spamspan"> <span class="u">user</span> [at] <span class="d">example [dot] com</span> </span>
spamspan_callback	callback function for preg_replace_callback
spamspan_convertmailto
spamspan_filter	Implementation of hook_filter().
spamspan_filter_tips	Implementation of hook_filter_tips().
spamspan_footer	Implementation of hook_footer().
spamspan_help	Implementation of hook_help().