node.module

<?php
// $Id$

/**
 * @file
 * The core that allows content to be submitted to the site.
 */

define('NODE_NEW_LIMIT', time() - 30 * 24 * 60 * 60);

/**
 * Implementation of hook_help().
 */
function node_help($section) {
  switch ($section) {
    case 'admin/help#node':
      $output = t("
      <h3>Nodes</h3>
      <p>The core of the Drupal system is the node. All of the contents of the system are placed in nodes, or extensions of nodes.
      A base node contains:<dl>
      <dt>A Title</dt><dd>Up to 128 characters of text that titles the node.</dd>
      <dt>A Teaser</dt><dd>A small block of text that is meant to get you interested in the rest of node. Drupal will automatically pull a small amount of the body of the node to make the teaser (To configure how long the teaser will be <a href=\"%teaser\">click here</a>). The teaser can be changed if you don't like what Drupal grabs.</dd>
      <dt>The Body</dt><dd>The main text that comprises your content.</dd>
      <dt>A Type</dt><dd>What kind of node is this? Blog, book, forum, comment, unextended, etc.</dd>
      <dt>An Author</dt><dd>The author's name. It will either be \"anonymous\" or a valid user. You <em>cannot</em> set it to an arbitrary value.</dd>
      <dt>Authored on</dt><dd>The date the node was written.</dd>
      <dt>Changed</dt><dd>The last time this node was changed.</dd>
      <dt>Sticky at top of lists</dt><dd>In listings such as the frontpage or a taxonomy overview the teasers of a selected amount of nodes is displayed. If you want to force a node to appear on the top of such a listing, you must set it to 'sticky'. This way it will float to the top of a listing, and it will not be pushed down by newer content.
      <dt>Allow user comments</dt><dd>A node can have comments. These comments can be written by other users (Read-write), or only by admins (Read-only).</dd>
      <dt>Revisions</dt><dd>Drupal has a revision system so that you can \"roll back\" to an older version of a post if the new version is not what you want.</dd>
      <dt>Promote to front page</dt><dd>To get people to look at the new stuff on your site you can choose to move it to the front page. The front page is configured to show the teasers from only a few of the total nodes you have on your site (To configure how many teasers <a href=\"%teaser\">click here</a>).</dd>
      <dt>Published</dt><dd>When using Drupal's moderation system a node remains unpublished -- unavailable to non-moderators -- until it is marked Published.</dd></dl>
      <p>Now that you know what is in a node, here are some of the types of nodes available.</p>", array("%teaser" => url("admin/node/configure/settings")));

      foreach (node_list() as $type => $module) {
        $output .= '<h3>'. t('Node type: %module', array('%module' => node_invoke($type, 'node_name'))). '</h3>';
        $output .= implode("\n", module_invoke_all('help', 'node/add#'. $type));
      }

      return $output;

    case 'admin/modules#description':
      return t('Allows content to be submitted to the site and displayed on pages.');
    case 'admin/node/configure':
    case 'admin/node/configure/settings':
      return t('<p>Settings for the core of Drupal. Almost everything is a node so these settings will affect most of the site.</p>');
    case 'admin/node':
      return t('<p>Below is a list of all of the posts on your site. Other forms of content are listed elsewhere (e.g. <a href="%comments">comments</a>).</p><p>Clicking a title views the post, while clicking an author\'s name views their user information.</p>', array('%comments' => url('admin/comment')));
    case 'admin/node/search':
      return t('<p>Enter a simple pattern to search for a post. This can include the wildcard character *.<br />For example, a search for "br*" might return "bread bakers", "our daily bread" and "brenda".</p>');
  }

  if (arg(0) == 'node' && is_numeric(arg(1)) && arg(2) == 'revisions') {
    return t('The revisions let you track differences between multiple versions of a post.');
  }

  if (arg(0) == 'node' && arg(1) == 'add' && $type = arg(2)) {
    return variable_get($type .'_help', '');
  }
}

/**
 * Implementation of hook_cron().
 */
function node_cron() {
  db_query('DELETE FROM {history} WHERE timestamp < %d', NODE_NEW_LIMIT);
}

/**
 * Gather a listing of links to nodes.