Blocks before plugins

drupal-7-blocks.php

<?php
/**
 * Implements hook_block_info().
 */
function forum_block_info() {
  $blocks['active'] = array(
    'info' => t('Active forum topics'),
    'cache' => DRUPAL_CACHE_CUSTOM,
    'properties' => array('administrative' => TRUE),
  );
  $blocks['new'] = array(
    'info' => t('New forum topics'),
    'cache' => DRUPAL_CACHE_CUSTOM,
    'properties' => array('administrative' => TRUE),
  );
  return $blocks;
}

/**
 * Implements hook_block_configure().
 */
function forum_block_configure($delta = '') {
  $form['forum_block_num_' . $delta] = array(
    '#type' => 'select',
    '#title' => t('Number of topics'),
    '#default_value' => variable_get('forum_block_num_' . $delta, '5'),
    '#options' => drupal_map_assoc(range(2, 20))
  );
  return $form;
}

/**
 * Implements hook_block_save().
 */
function forum_block_save($delta = '', $edit = array()) {
  variable_set('forum_block_num_' . $delta, $edit['forum_block_num_' . $delta]);
}

/**
 * Implements hook_block_view().
 *
 * Generates a block containing the currently active forum topics and the most
 * recently added forum topics.
 */
function forum_block_view($delta = '') {
  $query = db_select('forum_index', 'f')
    ->fields('f')
    ->addTag('node_access');
  switch ($delta) {
    case 'active':
      $title = t('Active forum topics');
      $query
        ->orderBy('f.last_comment_timestamp', 'DESC')
        ->range(0, variable_get('forum_block_num_active', '5'));
      break;

    case 'new':
      $title = t('New forum topics');
      $query
        ->orderBy('f.created', 'DESC')
        ->range(0, variable_get('forum_block_num_new', '5'));
      break;
  }

  $block['subject'] = $title;
  // Cache based on the altered query. Enables us to cache with node access enabled.
  $block['content'] = drupal_render_cache_by_query($query, 'forum_block_view');
  $block['content']['#access'] = user_access('access content');
  return $block;
}