Adding certain length to teaser?

The whole thing came up as a module finally, here is the code :

<?php

/**
 * Implementation of hook_help().
 *
 * Throughout Drupal, hook_help() is used to display help text at the top of
 * pages. Some other parts of drupal pages get explanatory text from these hooks
 * as well. We use it here to provide a description of the module on the
 * module administration page.
 */
function teaser_management_help($section) {
  switch ($section) {
    case 'admin/modules#description':
      // This description is shown in the listing at admin/modules.
      return t('Allows the regeneration of teasers (usefull after a modification of the length for instance)');
  }
}

function teaser_management_form_alter($form_id, &$form) {

  $nodes_count = _teaser_management_nodes_count();

  switch ($form_id) {
    case 'node_configure':
      foreach(array_keys($form) as $form_elt) {
        if ($form_elt == 'teaser_length') {
          $form_cpy[$form_elt] = $form[$form_elt];
          $form_cpy['teaser_management'] = array(
            '#type'        => 'fieldset',
            '#title'       => t('Extended teaser management'),
            '#collapsible' => TRUE,
            '#collapsed'   => FALSE
          );
          $form_cpy['teaser_management']['update_teasers'] = array(
            '#type'          => 'checkbox',
            '#title'         => t('Update trimmed posts'),
            '#default_value' => 0,
            '#description'   => t('Check this in order to trim your posts upon submission of this page, based on the criteria chosen below.')
          );
          $form_cpy['teaser_management']['range_definition'] = array(
            '#type'        => 'fieldset',
            '#title'       => t('Range definition'),
            '#collapsible' => FALSE,
            '#description' => t('You can define a range of nodes\' teasers to modify (min. start is 0, max. end is the number of nodes). The range is not related to the nodes\' id, but rather to the way they are stored in your database. You currently have ' . $nodes_count . ' nodes in your database.')
          );
          $form_cpy['teaser_management']['range_definition']['update_range_teasers_start'] = array(
            '#type'          => 'textfield',
            '#title'         => t('Range start'),
            '#default_value' => variable_get('update_range_teasers_start', 0),
            '#size'          => 5,
            '#maxlength'     => 5
          );
          $form_cpy['teaser_management']['range_definition']['update_range_teasers_end'] = array(
            '#type'          => 'textfield',
            '#title'         => t('Range end'),
            '#default_value' => variable_get('update_range_teasers_end', 50),
            '#size'          => 5,
            '#maxlength'     => 5
          );
          $form_cpy['teaser_management']['update_teasers_method'] = array(
            '#type'          => 'radios',
            '#title'         => t('How to update teasers'),
            '#default_value' => variable_get('update_teasers_method', 0),
            '#options'       => array(
                                  t('Using range definition'),
                                  t('Only promoted nodes (those shown on your website\'s frontpage)')
                                ),
            '#description'   => t('You can choose which method of updating to apply.')
          );
        }
        else {
          $form_cpy[$form_elt] = $form[$form_elt];
        }
      }
      $form = $form_cpy;

      if (variable_get('update_teasers', 0)) {
        variable_set('update_teasers', 0);
        $limit = array(variable_get('update_range_teasers_start', 1), variable_get('update_range_teasers_end', 50));
        _teaser_management_trim(variable_get('update_teasers_method', 0), $limit);
      }
      break;
  }
}

function _teaser_management_nodes_count() {
  $sql = 'SELECT count(nid) num FROM {node}';

  $result = db_query($sql);
  $nodes_count = db_fetch_array($result);

  return $nodes_count['num'];
}

function _teaser_management_trim($promoted_only, &$limit) {

  $sql = 'SELECT nid FROM {node} LIMIT %d, %d';
  if ($promoted_only) {
    $sql .= ' WHERE promote = %d';
    array_push($limit, 1);
  }

  $result = db_query($sql, $limit);

  while ($node_id = db_fetch_object($result)) {
    $node = node_load($node_id->nid);
    if (!isset($node->teaser))
      continue;
    $node->teaser = isset($node->body) ? node_teaser($node->body, isset($node->format) ? $node->format : NULL) : '';
    $node_query = 'UPDATE {node_revisions} SET `teaser` = \'%s\' WHERE nid=\'%d\'';

    $query_values = array($node->teaser, $node->nid);
    db_query($node_query, $query_values);
  }
}

?>

You should name it teaser_management.module and enable it. In order to use it, you go to administer > settings > post. It should normally appear there. If you want your posts to be trimmed next time you click on the submit button on the bottom of the page, check the "Update trimmed posts" box. You then must choose a range of nodes to trim. Attention, this has nothing to do with the nodes id, it's just passed as a LIMIT parameter to the database (for the time being, I'll make some basic verifications afterwards). Finally you choose the action to take.
Either you choose to trim all nodes in the range you defined (don't make it too big, especially if your website is not hosted on your computer because the script will most probably be stopped before it could have finished; you can make steps of 30, that's should be reasonable enough).
The second possible action is to only trim the nodes that are promoted, that is showed on your frontpage. Since I don't see another place where teasers might be used, that should be enough I think. But I'm most probably wrong :).

Anyway, I think I'll keep working on this module a bit. Any feedback is welcomed.

Btw, let me repeat once more : I strongly suggest that you backup your database and keep a copy of the old node.module file before attempting anything. If your data is too important, don't even bother and wait at least for the (eventual :)) validation of my code by the Drupal team. Won't be held responsible for any problem this code might cause ;).

acp

can you also use this to tweak teaser length inside taxonomy blocks or just plain blocks?