signature_forum.module in Signatures for Forums 6

Tweaks signatures in ways inspired by other traditional forum software:

• When a user changes their signature, all their posts will be updated.
• Signatures are automatically added to posts, instead of being inserted into the post text.
• The administrator can choose the input filter for signatures, allowing BBCode or HTML to be used.
• Signatures are longer than the the Drupal default (to match other forum software).
• Conditional signatures, these are hidden (or rel=nofollow'd) if a post is under a particular length.
• Show signature only once per conversation (also works with threading).

File

signature_forum.module

<?php

/**
 * @file
 * Tweaks signatures in ways inspired by other traditional forum software:
 *
 * - When a user changes their signature, all their posts will be updated.
 * - Signatures are automatically added to posts, instead of being inserted
 *   into the post text.
 * - The administrator can choose the input filter for signatures, allowing
 *   BBCode or HTML to be used.
 * - Signatures are longer than the the Drupal default (to match other forum
 *   software).
 * - Conditional signatures, these are hidden (or rel=nofollow'd) if a post is
 *   under a particular length.
 * - Show signature only once per conversation (also works with threading).
 */

/**
 * Do not display a signature when the content is under a certain length.
 */
define('MIN_CONTENT_ACTION_DO_NOT_DISPLAY', 0);

/**
 * Run the signature through an additional filter if the content is under a certain length.
 * Good for adding rel=nofollow to all links.
 */
define('MIN_CONTENT_ACTION_ADDITIONAL_FILTER', 1);

/**
 * Show a signature in all user posts.
 */
define('SHOW_ONCE_OPTIONS_ALWAYS', 0);

/**
 * Show a user's signature only once per conversation.
 */
define('SHOW_ONCE_OPTIONS_ONCE', 1);

/**
 * Implementation of hook_help().
 */
function signature_forum_help($path, $arg) {
  switch ($path) {
    case "admin/modules#description":
      return t("Tweaks signatures in ways inspired by other traditional forum software. Allows much longer signatures than the Drupal default; also users may be allowed to use different formats like BBCode (with the BBCode module downloadable from drupal.org) or HTML in their signatures.");
  }
}

/**
 * Implementation of hook_perm().
 */
function signature_forum_perm() {
  return array(
    'administer Signatures for Forums',
  );
}

/**
 * Implementation of hook_menu().
 */
function signature_forum_menu() {
  $items['admin/settings/signature_forum'] = array(
    'title' => 'Signatures for Forums',
    'description' => "Manages users' signatures.",
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'signature_forum_admin_settings',
    ),
    'access arguments' => array(
      'administer Signatures for Forums',
    ),
  );
  return $items;
}

/**
 * Admin settings form.
 *
 * TODO: Move admin form to existing signature form under admin/user/settings.
 */
function signature_forum_admin_settings() {
  $settings = variable_get('signature_forum_settings', signature_forum_defaults());

  // Check to ensure the admin has enabled signatures in admin/user/settings.
  if (!variable_get('user_signatures', FALSE)) {
    drupal_set_message(t('Note: signatures are switched off, enable them under <a href="@settings-page">Administer -> User management -> User settings</a>', array(
      '@settings-page' => url('admin/user/settings'),
    )));
  }
  $form['signature'] = array(
    '#type' => 'fieldset',
    '#title' => t('Show signatures with nodes and comments for'),
  );
  foreach (node_get_types('names') as $type => $name) {
    $form['signature']['signature_forum_show_for_' . $type] = array(
      '#type' => 'checkbox',
      '#title' => $name,
      '#return_value' => 1,
      '#default_value' => isset($settings['signature_forum_show_for_' . $type]) ? $settings['signature_forum_show_for_' . $type] : FALSE,
    );
  }
  $form['template'] = array(
    '#type' => 'textarea',
    '#title' => t('Template for signatures'),
    '#default_value' => $settings['signature_forum_template'],
    '#description' => t("%s will be replaced with the user's signature."),
  );
  $form['format'] = filter_form($settings['signature_forum_format']);
  $form['content_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Minimum content length'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );
  $form['content_settings']['min_content_length'] = array(
    '#type' => 'textfield',
    '#title' => t('Minimum content length'),
    '#size' => 3,
    '#maxlength' => 10,
    '#default_value' => $settings['signature_forum_min_content_length'],
    '#description' => t('The minimum number of characters in the content a signature is being attached to. 0 means no limit.'),
  );
  $form['content_settings']['min_content_length_action'] = array(
    '#type' => 'radios',
    '#title' => t('Minimum content action'),
    '#default_value' => $settings['signature_forum_min_content_length_action'],
    '#options' => array(
      MIN_CONTENT_ACTION_DO_NOT_DISPLAY => t('Do not display signature'),
      MIN_CONTENT_ACTION_ADDITIONAL_FILTER => t('Run through an additional filter'),
    ),
    '#description' => t('What to do if the content is under the minimum length. Set the filter below.'),
  );
  $form['content_settings']['min_content_length_filter'] = filter_form($settings['signature_forum_min_content_length_filter'], NULL, array(
    'min_content_length_filter',
  ));
  $form['content_settings']['min_content_length_filter']['#title'] = t('Minimum content additional filter format (if enabled)');

  // If admin has opted to run signature through additional filter when content too short,
  // expand the additional filter selection fieldset.
  if ($settings['signature_forum_min_content_length_action'] == MIN_CONTENT_ACTION_ADDITIONAL_FILTER) {
    $form['content_settings']['min_content_length_filter']['#collapsed'] = FALSE;
  }
  $roles = user_roles(TRUE);
  $form['content_settings']['roles'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Exempt roles'),
    '#default_value' => isset($settings['signature_forum_roles']) ? $settings['signature_forum_roles'] : array(),
    '#options' => $roles,
    '#description' => t('Members of these roles will be exempt from content length settings.'),
  );
  $form['show_once'] = array(
    '#type' => 'fieldset',
    '#title' => t('Per-conversation signatures'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );
  $form['show_once']['show_once_options'] = array(
    '#type' => 'radios',
    '#title' => t("Show a user's signature"),
    '#default_value' => $settings['signature_forum_show_once_options'],
    '#options' => array(
      SHOW_ONCE_OPTIONS_ALWAYS => t('Always'),
      SHOW_ONCE_OPTIONS_ONCE => t('Once per conversation'),
    ),
  );
  $form['show_once']['show_once_roles'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Exempt roles'),
    '#default_value' => isset($settings['signature_forum_show_once_roles']) ? $settings['signature_forum_show_once_roles'] : array(),
    '#options' => $roles,
    '#description' => t('Members of these roles will have their signatures shown in every post.'),
  );
  $form['signature_defaults'] = array(
    '#type' => 'fieldset',
    '#title' => t('Per-post settings'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
    '#description' => t('Users will see a checkbox below the comment form allowing them to choose whether or not to use their signature. If signatures are not enabled for a content type, this setting will have no effect.'),
  );
  if (module_exists('comment')) {
    $form['signature_defaults']['signature_forum_default_comments'] = array(
      '#type' => 'checkbox',
      '#title' => t('Core Comments'),
      '#return_value' => 1,
      '#default_value' => isset($settings['signature_forum_default_comments']) ? $settings['signature_forum_default_comments'] : FALSE,
    );
  }
  foreach (node_get_types('names') as $type => $name) {
    $form['signature_defaults']['signature_forum_default_for_' . $type] = array(
      '#type' => 'checkbox',
      '#title' => $name,
      '#return_value' => 1,
      '#default_value' => isset($settings['signature_forum_default_for_' . $type]) ? $settings['signature_forum_default_for_' . $type] : FALSE,
    );
  }
  $form['signature_defaults']['signature_forum_allow_user_default'] = array(
    '#type' => 'radios',
    '#title' => t('Allow users to choose their own global default'),
    '#default_value' => isset($settings['signature_forum_allow_user_default']) ? $settings['signature_forum_allow_user_default'] : 0,
    '#options' => array(
      t('No'),
      t('Yes'),
    ),
    '#description' => t("This will add an option in a user's profile settings where they can choose whether their signature should be used by default."),
  );
  $form['signature_other'] = array(
    '#type' => 'fieldset',
    '#title' => t('Other options'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );
  $form['signature_other']['line_limit'] = array(
    '#type' => 'textfield',
    '#title' => t('Line limit'),
    '#size' => 3,
    '#maxlength' => 10,
    '#default_value' => $settings['signature_forum_line_limit'],
    '#description' => t('The maximum number of lines allowed in a signature. 0 means no limit. Note: existing signatures that are too long will not be changed.'),
  );
  $form['signature_other']['char_limit'] = array(
    '#type' => 'textfield',
    '#title' => t('Character limit'),
    '#size' => 5,
    '#maxlength' => 10,
    '#default_value' => $settings['signature_forum_char_limit'],
    '#description' => t('The maximum number of characters allowed in a signature. 0 means no limit. Note: existing signatures that are too long will not be changed.'),
  );
  $form['signature_other']['delete_signatures'] = array(
    '#type' => 'checkbox',
    '#title' => t('Delete embedded signatures'),
    '#description' => t('Deletes signatures that are embedded in existing comments (warning: cannot be undone!).'),
    '#default_value' => FALSE,
  );
  $form['signature_other']['auto_insert'] = array(
    '#type' => 'checkbox',
    '#title' => t('Automatically add signatures to content'),
    '#description' => t('If this is switched on signatures will automatically be added to content. Themers may wish to switch this off, so the signature may be positioned in the templates manually.'),
    '#default_value' => $settings['signature_forum_auto_insert'],
  );
  $form = system_settings_form($form);
  unset($form['#submit']);
  $form['#submit'][] = 'signature_forum_admin_settings_submit';
  return $form;
}

/**
 * Default signature settings.
 */
function signature_forum_defaults() {
  return array(
    'signature_forum_template' => "__________________\n<p>%s</p>",
    'signature_forum_format' => FILTER_FORMAT_DEFAULT,
    'signature_forum_line_limit' => 0,
    'signature_forum_char_limit' => 0,
    'signature_forum_min_content_length' => 0,
    'signature_forum_min_content_length_action' => MIN_CONTENT_ACTION_DO_NOT_DISPLAY,
    'signature_forum_min_content_length_filter' => FILTER_FORMAT_DEFAULT,
    'signature_forum_show_once_options' => SHOW_ONCE_OPTIONS_ALWAYS,
    // do not automatically allow users to choose their own default signature attachment setting
    'signature_forum_allow_user_default' => 1,
    // Do not automatically insert signatures into nodes if Advanced Forum is
    // installed (as AF does this in the theme layer).
    'signature_forum_auto_insert' => module_exists('advanced_forum') ? FALSE : TRUE,
  );
}

/**
 * Admin settings form submit.
 */
function signature_forum_admin_settings_submit($form, &$form_state) {

  // If the user hit the 'Reset to defaults button' we do that then return
  if ($form_state['clicked_button']['#value'] == 'Reset to defaults') {
    variable_set('signature_forum_settings', signature_forum_defaults());
    drupal_set_message(t('The configuration options have been reset to their default values.'));
    return;
  }
  $settings = array();
  foreach ($form_state['values'] as $form_value_key => $form_value_value) {
    if (drupal_substr($form_value_key, 0, drupal_strlen('signature_forum_show_for_')) == 'signature_forum_show_for_') {
      $settings[$form_value_key] = $form_value_value;
    }
    elseif (drupal_substr($form_value_key, 0, drupal_strlen('signature_forum_default_for_')) == 'signature_forum_default_for_') {
      $settings[$form_value_key] = $form_value_value;
    }
    elseif ($form_value_key == 'signature_forum_default_comments') {
      $settings[$form_value_key] = $form_value_value;
    }
  }
  if ($form_state['values']['delete_signatures']) {
    switch ($GLOBALS['db_type']) {
      case 'mysql':
      case 'mysqli':
        db_query("UPDATE {comments} c INNER JOIN {users_signature} u ON c.uid=u.uid\n          SET c.comment=left(c.comment, length(c.comment) - length(u.signature))\n          WHERE right(c.comment, length(u.signature)) LIKE u.signature;");
        break;
      case 'pgsql':
        db_query("UPDATE {comments} SET comment=substring({comments}.comment from 1 for length({comments}.comment)-length({users_signature}.signature))\n          FROM {users_signature}\n          WHERE {comments}.comment LIKE '%' || {users_signature}.signature");
        break;
    }
    cache_clear_all(NULL, 'cache_page');
    cache_clear_all(NULL, 'cache_filter');
    drupal_set_message(t('Signatures in comments deleted.'));
  }
  $settings['signature_forum_template'] = $form_state['values']['template'];
  $settings['signature_forum_format'] = $form_state['values']['format'];
  $settings['signature_forum_line_limit'] = $form_state['values']['line_limit'];
  $settings['signature_forum_char_limit'] = $form_state['values']['char_limit'];
  $settings['signature_forum_min_content_length'] = $form_state['values']['min_content_length'];
  $settings['signature_forum_min_content_length_action'] = $form_state['values']['min_content_length_action'];
  $settings['signature_forum_min_content_length_filter'] = $form_state['values']['min_content_length_filter'];
  $settings['signature_forum_roles'] = $form_state['values']['roles'];
  $settings['signature_forum_show_once_options'] = $form_state['values']['show_once_options'];
  $settings['signature_forum_show_once_roles'] = $form_state['values']['show_once_roles'];
  $settings['signature_forum_auto_insert'] = $form_state['values']['auto_insert'];
  $settings['signature_forum_allow_user_default'] = $form_state['values']['signature_forum_allow_user_default'];
  variable_set('signature_forum_settings', $settings);
  drupal_set_message(t('The configuration options have been saved.'));
}

/**
 * Implementation of hook_user().
 */
function signature_forum_user($op, &$edit, &$account, $category = NULL) {

  // Re-route the user signature to this module's signature table.
  switch ($op) {
    case 'submit':

      // Check if the signature is set in the form
      // (#276349 - Signature deleted when editing profile).
      if (!isset($edit['signature'])) {
        break;
      }

      // If the user has a signature set update it, otherwise create a new entry.
      if (db_result(db_query("SELECT uid FROM {users_signature} WHERE uid = %d", $account->uid)) != FALSE) {
        db_query("UPDATE {users_signature} SET signature = '%s', status = %d WHERE uid = %d", array(
          $edit['signature'],
          $edit['signature_default_status'],
          $account->uid,
        ));
      }
      else {
        db_query("INSERT INTO {users_signature} (uid, signature, status) VALUES (%d, '%s', %d)", array(
          $account->uid,
          $edit['signature'],
          $edit['signature_default_status'],
        ));
      }
      unset($edit['signature']);
      break;
    case 'load':
      $signature = db_fetch_object(db_query("SELECT signature, status FROM {users_signature} WHERE uid = %d", $account->uid));

      // Bug #190446 OG puts $account->signature into comments
      $account->signature_forum = isset($signature->signature) ? $signature->signature : '';
      $account->signature_default_status = isset($signature->status) ? $signature->status : 1;
      break;
    case 'validate':
      $settings = variable_get('signature_forum_settings', signature_forum_defaults());

      // If the signature contains too many lines
      if ($settings['signature_forum_line_limit'] > 0 && substr_count($edit['signature'], "\n") > $settings['signature_forum_line_limit']) {
        form_set_error('signature', t('Maximum number of !max_lines lines allowed in signature exceeded.', array(
          '!max_lines' => $settings['signature_forum_line_limit'],
        )));
      }
      if ($settings['signature_forum_char_limit'] > 0 && drupal_strlen($edit['signature']) > $settings['signature_forum_char_limit']) {
        form_set_error('signature', t('Maximum number of @max_chars characters allowed in signature exceeded.', array(
          '@max_chars' => $settings['signature_forum_char_limit'],
        )));
      }
      break;
  }
}

/**
 * Implementation of hook_form_alter().
 */
function signature_forum_form_alter(&$form, &$form_state, $form_id) {
  $settings = variable_get('signature_forum_settings', signature_forum_defaults());

  // if signatures are disabled for all content types, hide signature field in user profile settings
  if ($form_id == 'user_profile_form' && variable_get('user_signatures', FALSE)) {
    $enabled = FALSE;
    foreach (node_get_types('names') as $type => $name) {
      if (!empty($settings['signature_forum_show_for_' . $type]) && $settings['signature_forum_show_for_' . $type] == 1) {
        $enabled = TRUE;
        break;
      }
    }
    if (!$enabled) {
      unset($form['signature_settings']);
    }
    elseif ($form['_category']['#value'] == 'account') {

      // Remove core signature input format selection, since Signatures for
      // Forums input formats are selected in the administration settings.
      unset($form['signature_settings']['signature_format']);

      // Again, since the input format is set in the administration settings, we
      // only want to provide enough information for modules like WYSIWYG to
      // determine which input format has been selected, and provide the user
      // formatting hints.
      // See: http://api.drupal.org/api/function/filter_form/6
      $extra = theme('filter_tips_more_info');
      $value = filter_resolve_format($settings['signature_forum_format']);

      // Only one format available: use a hidden form item and only show tips.
      $tips = _filter_tips($value, FALSE);
      $form['signature_settings']['format'][$settings['signature_forum_format']] = array(
        '#type' => 'value',
        '#value' => $settings['signature_forum_format'],
        '#parents' => array(
          'format',
        ),
      );
      $form['signature_settings']['format']['format']['guidelines'] = array(
        '#title' => t('Formatting guidelines'),
        '#value' => theme('filter_tips', $tips, FALSE, $extra),
      );
      $form_format['signature_settings']['format'][] = array(
        '#value' => $extra,
      );
      $account = $form['_account']['#value'];
      $form['signature_settings']['signature']['#default_value'] = $account->signature_forum;
      if ($settings['signature_forum_allow_user_default']) {
        $form['signature_settings']['signature_default_status'] = array(
          '#type' => 'checkbox',
          '#title' => t('Show signature by default'),
          '#description' => t('Whenever you add a comment you can choose not to use your signature. Use this to turn off your signature by default.'),
          '#default_value' => $account->signature_default_status,
        );
      }
    }
  }
  elseif (variable_get('user_signatures', FALSE) && (($form_id == 'forum_reply_node_form' || isset($form['type']) && isset($form['#node']) && $form['type']['#value'] . '_node_form' == $form_id) && $settings['signature_forum_show_for_' . $form['type']['#value']] == 1) || $form_id == 'comment_form' && $settings['signature_forum_default_comments'] == 1) {
    global $user;

    // Get default value for whether to use signature are we editing a standard
    // drupal comment?
    if (isset($form['cid']) && $form['cid']['#value'] > 0) {
      $use_signature = signature_forum_get_status($form['cid']['#value'], 'comment');
    }
    elseif ($form['nid']['#value'] > 0 && isset($form['type']['#value'])) {
      $use_signature = signature_forum_get_status($form['nid']['#value'], 'node');
    }
    elseif (isset($user->signature_default_status)) {
      $use_signature = $user->signature_default_status;
    }
    else {

      // Get site-wide default setting.
      $use_signature = $settings['signature_forum_default_for_' . $form['type']['#value']];
    }
    $form['signature_forum'] = array(
      '#type' => 'checkbox',
      '#title' => t('Attach signature'),
      '#description' => t('Signature can be changed in <a href="@signature_link">account settings</a>.', array(
        '@signature_link' => url('user/' . $user->uid . '/edit'),
      )),
      '#default_value' => $use_signature,
    );
  }
}

/**
 * Implementation of hook_nodeapi().
 */
function signature_forum_nodeapi(&$node, $op, $teaser, $page) {
  if (!$teaser && $op == 'view') {
    $settings = variable_get('signature_forum_settings', signature_forum_defaults());
    if ($settings['signature_forum_auto_insert']) {
      $node->content['body']['#value'] .= signature_forum_get_signature($node);
    }
  }
  elseif ($op == 'insert' || $op == 'update') {
    $delta = $node->nid;
    $status = $node->signature_forum;
    signature_forum_save_comment_status($delta, 'node', $status);
  }
}

/**
 * Implementation of hook_comment().
 */
function signature_forum_comment(&$comment, $op) {
  if ($op == 'view') {
    $settings = variable_get('signature_forum_settings', signature_forum_defaults());
    if ($settings['signature_forum_auto_insert']) {
      $comment->comment .= signature_forum_get_signature($comment);
    }
  }
  elseif ($op == 'insert' || $op == 'update') {
    $delta = $comment['cid'];
    $status = $comment['signature_forum'];
    signature_forum_save_comment_status($delta, 'comment', $status);
  }
}

/**
 * Find if uid is in exception lists.
 *
 * @param $uid
 *   User ID.
 * @param $op
 *   Which exception list, this may be:
 *     - "min_length".
 *     - "show_once".
 * @return
 *   TRUE if uid is in exception list. FALSE otherwise.
 */
function signature_forum_user_exception($uid = 0, $op) {
  static $cache = array();
  $settings = variable_get('signature_forum_settings', signature_forum_defaults());
  if (!isset($cache[$uid]) || !is_array($cache[$uid])) {
    $result = db_query("SELECT r.rid AS rid FROM {role} r INNER JOIN {users_roles} ur ON ur.rid = r.rid WHERE ur.uid = %d", $uid);
    $cache[$uid] = array();
    while ($role = db_fetch_object($result)) {
      $cache[$uid][$role->rid] = $role->rid;
    }
    if ($uid > 0) {
      $cache[$uid][DRUPAL_AUTHENTICATED_RID] = DRUPAL_AUTHENTICATED_RID;
    }
  }
  foreach ($cache[$uid] as $rid) {
    switch ($op) {
      case 'min_length':
        if ($settings['signature_forum_roles'][$rid] == $rid) {
          return TRUE;
        }
        break;
      case 'show_once':
        if ($settings['signature_forum_show_once_roles'][$rid] == $rid) {
          return TRUE;
        }
        break;
    }
  }
  return FALSE;
}

/**
 * Retrieve signature for a given user.
 *
 * @param &$a1
 *   Object that is either a node or comment.
 * @return
 *   Signature of the user who posted the content passed in &$a1.
 */
function signature_forum_get_signature($a1) {
  static $node_type;
  static $cache = array();
  $settings = variable_get('signature_forum_settings', signature_forum_defaults());

  // If signatures are disabled.
  if (!variable_get('user_signatures', FALSE)) {
    return;
  }

  // Get the node type, if it's not already set.
  if (!isset($node_type)) {
    if (!isset($a1->type)) {

      // This is a comment, so we need to get the node type from the DB.
      // We add the type to our comment object so it can be passed to _comment_get_display_setting().
      $a1->type = db_result(db_query("SELECT type FROM {node} WHERE nid = %d", $a1->nid));
    }
    $node_type = $a1->type;
  }

  // If signatures are not shown for this node type.
  if (!$settings['signature_forum_show_for_' . $node_type]) {
    return;
  }

  // Get length of comment.
  if (isset($a1->cid) || !isset($a1->revision_timestamp)) {
    $content_length = drupal_strlen(strip_tags($a1->comment));
  }
  else {
    $content_length = drupal_strlen(strip_tags($a1->content['body']['#value']));
  }

  // Content minimum length not set, is longer than minimum or the user has a role that is an exception.
  if ($content_length >= $settings['signature_forum_min_content_length'] || signature_forum_user_exception($a1->uid, 'min_length')) {
    $load_signature = TRUE;
  }
  elseif ($settings['signature_forum_min_content_length_action'] == MIN_CONTENT_ACTION_DO_NOT_DISPLAY) {

    // We still call the theme with a blank string, a themer may still wish to
    // output something to keep their theme consistent.
    return theme('signature_forum', '');
  }

  // Check if signature is disabled for this comment/node.
  if (isset($a1->cid)) {
    $id = $a1->cid;
    $type = 'comment';
  }
  else {
    $id = $a1->nid;
    $type = 'node';
  }
  $signature_status = signature_forum_get_status($id, $type);
  if (!$signature_status) {
    return theme('signature_forum', '');
  }
  if (isset($cache[$a1->uid])) {

    // If the signature is in the cache it has been displayed before.
    if ($settings['signature_forum_show_once_options'] == SHOW_ONCE_OPTIONS_ALWAYS || signature_forum_user_exception($a1->uid, 'show_once')) {

      // Make implicit copy of signature so original, in cache, is preserved.
      $signature = (string) $cache[$a1->uid];
      $load_signature = FALSE;
    }
    else {
      $signature = '';
      $load_signature = FALSE;
    }
  }
  else {

    // We're not on the first page, or we're viewing a single comment, i.e. is_numeric(arg(2)).
    if (isset($_GET['page']) || is_numeric(arg(2))) {

      // If the signature is set to always show, the user is exempt from show once rules
      // or this is not a comment (ergo it is the node and must be the first post).
      if ($settings['signature_forum_show_once_options'] == SHOW_ONCE_OPTIONS_ALWAYS || !isset($a1->cid) || signature_forum_user_exception($a1->uid, 'show_once')) {
        $load_signature = TRUE;
      }
      else {

        // _comment_get_display_setting() requires a node object, we fake one for it.
        if (!isset($a1->type)) {
          $fake_node = new stdClass();
          $fake_node->type = db_result(db_query("SELECT type from {node} WHERE nid = %d", $a1->nid));
        }
        else {

          // If $a1 is a node (not a comment) make an implicit copy.
          $fake_node = (object) $a1;
        }

        // We cache these values to avoid extra DB queries.
        static $mode;
        static $order;
        if (is_null($mode) || is_null($order)) {
          $mode = _comment_get_display_setting('mode', $fake_node);
          $order = _comment_get_display_setting('sort', $fake_node);
        }
        unset($fake_node);

        // If only a single comment is being displayed the comment object does not
        // contain the thread field.
        if (!isset($a1->thread)) {
          $a1->thread = db_result(db_query("SELECT thread FROM {comments} WHERE cid = %d", $a1->cid));
        }

        // If there's a result from this query it means the signature has appeared
        // previously in the topic.
        $sql = "SELECT cid FROM {comments} WHERE nid = %d AND uid = %d AND status = %d";
        $query_args = array(
          $a1->nid,
          $a1->uid,
          COMMENT_PUBLISHED,
        );

        // We need to ensure any posts displayed earlier are greater than the minimum length.
        if ($settings['signature_forum_min_content_length'] > 0 && !signature_forum_user_exception($a1->uid, 'min_length')) {
          $sql .= " AND LENGTH(comment) > %d";
          $query_args[] = $settings['signature_forum_min_content_length'];
        }
        if ($order == COMMENT_ORDER_NEWEST_FIRST) {
          if ($mode == COMMENT_MODE_FLAT_COLLAPSED || $mode == COMMENT_MODE_FLAT_EXPANDED) {
            $sql .= " AND cid > %d\n              ORDER BY cid DESC";
            $query_args[] = $a1->cid;
          }
          else {
            $sql .= " AND thread > '%s'\n              ORDER BY thread DESC";
            $query_args[] = $a1->thread;
          }
        }
        elseif ($order == COMMENT_ORDER_OLDEST_FIRST) {
          if ($mode == COMMENT_MODE_FLAT_COLLAPSED || $mode == COMMENT_MODE_FLAT_EXPANDED) {
            $sql .= " AND cid < %d\n              ORDER BY cid";
            $query_args[] = $a1->cid;
          }
          else {
            $sql .= " AND SUBSTRING(thread, 1, (LENGTH(thread) - 1)) < SUBSTRING('%s', 1, (LENGTH('%s') - 1))\n              ORDER BY SUBSTRING(thread, 1, (LENGTH(thread) - 1))";
            $query_args[] = $a1->thread;
            $query_args[] = $a1->thread;
          }
        }

        // If there is a result then this is not the first post in this topic
        // by this user.
        if (!db_result(db_query_range($sql, $query_args, 0, 1))) {
          $load_signature = TRUE;
        }
        else {
          $signature = '';

          // We add a blank entry to the cache so the above query doesn't need to
          // be run for subsequent posts by this user.
          $cache[$a1->uid] = '';
          $load_signature = FALSE;
        }

        // Note: we do not need to check the node as it would already be in the
        // $cache. The node is always shown first, regardless of comment order.
      }
    }
    else {
      $load_signature = TRUE;
    }
  }

  // Load the signature and add it to the cache.
  if ($load_signature == TRUE) {
    $signature = db_result(db_query("SELECT signature FROM {users_signature} WHERE uid = %d", $a1->uid));
    $cache[$a1->uid] = (string) $signature;
  }

  // Prevent the signature from being put through input filters if it's empty.
  if ($signature == '') {
    return theme('signature_forum', $signature);
  }

  // We tell check_markup to not check user permissions as the filter is set by
  // the administrator.
  $signature = check_markup($signature, $settings['signature_forum_format'], FALSE);

  // If the content is under the minimum length, the user is not exempt and
  // the signature is set to be run through an extra filter (this can be the only option
  // as other cases have already been handled above: there is no need to add a
  // $settings['signature_forum_show_once_options'] check in here!).
  if ($content_length < $settings['signature_forum_min_content_length'] && !signature_forum_user_exception($a1->uid, 'min_length')) {
    $signature = check_markup($signature, $settings['signature_forum_min_content_length_filter'], FALSE);
  }
  $signature = sprintf($settings['signature_forum_template'], trim($signature));
  return theme('signature_forum', $signature);
}

/**
 * Implementation of hook_theme().
 *
 * @ingroup themeable
 */
function signature_forum_theme() {
  return array(
    'signature_forum' => array(
      'arguments' => array(
        'signature' => NULL,
      ),
      'template' => 'signature',
    ),
  );
}

/**
 * Save the signature status for a comment
 * @param $delta
 *  An integer containing the id of a comment or node
 * @param $status
 *  A Boolean for whether or not the signature should be attached to this comment or node
 */
function signature_forum_save_comment_status($delta, $type, $status = 0) {
  db_query("UPDATE {signature_post} SET status = %d WHERE delta = %d AND type = '%s'", array(
    $status,
    $delta,
    $type,
  ));
  if (!db_affected_rows()) {
    db_query("INSERT INTO {signature_post} (delta, type, status) VALUES (%d, '%s', %d)", array(
      $delta,
      $type,
      $status,
    ));
  }
}

/**
 * Get the status for whether signature should be used for a particular node or comment
 * @param $delta
 *  An integer containing the id of a comment or node
 * @return
 *  TRUE if signature should be used, FALSE if it should be hidden.
 */
function signature_forum_get_status($delta, $type) {
  return db_result(db_query("SELECT status from {signature_post} WHERE delta = %d AND type = '%s'", $delta, $type));
}

Functions

Name	Description
signature_forum_admin_settings	Admin settings form.
signature_forum_admin_settings_submit	Admin settings form submit.
signature_forum_comment	Implementation of hook_comment().
signature_forum_defaults	Default signature settings.
signature_forum_form_alter	Implementation of hook_form_alter().
signature_forum_get_signature	Retrieve signature for a given user.
signature_forum_get_status	Get the status for whether signature should be used for a particular node or comment
signature_forum_help	Implementation of hook_help().
signature_forum_menu	Implementation of hook_menu().
signature_forum_nodeapi	Implementation of hook_nodeapi().
signature_forum_perm	Implementation of hook_perm().
signature_forum_save_comment_status	Save the signature status for a comment
signature_forum_theme	Implementation of hook_theme().
signature_forum_user	Implementation of hook_user().
signature_forum_user_exception	Find if uid is in exception lists.

Constants

Name	Description
MIN_CONTENT_ACTION_ADDITIONAL_FILTER	Run the signature through an additional filter if the content is under a certain length. Good for adding rel=nofollow to all links.
MIN_CONTENT_ACTION_DO_NOT_DISPLAY	Do not display a signature when the content is under a certain length.
SHOW_ONCE_OPTIONS_ALWAYS	Show a signature in all user posts.
SHOW_ONCE_OPTIONS_ONCE	Show a user's signature only once per conversation.