block.module

<?php
// $Id$

/**
 * @file
 * Controls the boxes that are displayed around the main content.
 */

/**
 * Implementation of hook_help().
 */
function block_help($section) {
  switch ($section) {
    case 'admin/help#block':
      return t('
<p>Blocks are the boxes visible in the sidebar(s) of your web site. These are usually generated automatically by modules (e.g. recent forum topics), but you can also create your own blocks.</p>
<p>The sidebar each block appears in depends on both which theme you are using (some are left-only, some right, some both), and on the settings in block management.</p>
<p>The block management screen lets you specify the vertical sort-order of the blocks within a sidebar. You do this by assigning a weight to each block. Lighter blocks (smaller weight) "float up" towards the top of the sidebar. Heavier ones "sink down" towards the bottom of it.</p>
<p>A block\'s visibility depends on:</p>
<ul>
<li>Its enabled checkbox. Disabled blocks are never shown.</li>
<li>Its throttle checkbox. Throttled blocks are hidden during high server loads.</li>
<li>Its path options. Blocks can be configured to only show/hide on certain pages</li>.
<li>User settings. You can choose to let your users decide whether to show/hide certain blocks.</li>
<li>Its function. Dynamic blocks (such as those defined by modules) may be empty on certain pages and will not be shown.</li>
</ul>

<h3>Administrator defined blocks</h3>
<p>An administrator defined block contains content supplied by you (as opposed to being generated automatically by a module). Each admin-defined block consists of a title, a description, and a body which can be as long as you wish. The Drupal engine will render the content of the block.</p>');
    case 'admin/modules#description':
      return t('Controls the boxes that are displayed around the main content.');
    case 'admin/block':
      return t("
<p>Blocks are the boxes in the left and right side bars of the web site. They are made available by modules or created manually.</p>
<p>Only enabled blocks are shown. You can position the blocks by deciding which side of the page they will show up on (region) and in which order they appear (weight).</p>
<p>If you want certain blocks to disable themselves temporarily during high server loads, check the 'Throttle' box. You can configure the auto-throttle on the <a href=\"%throttle\">throttle configuration page</a> after having enabled the throttle module.
", array('%throttle' => url('admin/settings/throttle')));
    case 'admin/block/add':
      return t("Here you can create a new block. Once you have created this block you must make it active and give it a place on the page using <a href=\"%overview\">blocks</a>. The title is used when displaying the block. The description is used in the \"block\" column on the <a href=\"%overview\">blocks</a> page.", array('%overview' => url('admin/block')));
  }
}

/**
 * Menu callback; presents the block-specific information from admin/help.
 */
function block_help_page() {
  print theme('page', block_help('admin/help#block'));
}

/**
 * Implementation of hook_perm().
 */
function block_perm() {
  return array('administer blocks');
}

/**
 * Implementation of hook_menu().
 */
function block_menu($may_cache) {
  $items = array();

  if ($may_cache) {
    $items[] = array('path' => 'admin/block', 'title' => t('blocks'),
      'access' => user_access('administer blocks'),
      'callback' => 'block_admin');
    $items[] = array('path' => 'admin/block/list', 'title' => t('list'),
      'type' => MENU_DEFAULT_LOCAL_TASK, 'weight' => -10);
    $items[] = array('path' => 'admin/block/configure', 'title' => t('configure block'),
      'access' => user_access('administer blocks'),
      'callback' => 'block_admin_configure',
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/block/delete', 'title' => t('delete block'),
      'access' => user_access('administer blocks'),
      'callback' => 'block_box_delete',
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/block/add', 'title' => t('add'),
      'access' => user_access('administer blocks'),
      'callback' => 'block_box_add',
      'type' => MENU_LOCAL_TASK);
  }

  return $items;
}

/**
 * Implementation of hook_block().
 *
 * Generates the administrator-defined blocks for display.
 */
function block_block($op = 'list', $delta = 0, $edit = array()) {
  switch ($op) {
    case 'list':
      $result = db_query('SELECT bid, title, info FROM {boxes} ORDER BY title');
      while ($block = db_fetch_object($result)) {
        $blocks[$block->bid]['info'] = $block->info;
      }
      return $blocks;

    case 'configure':
      $box = block_box_get($delta);
      if (filter_access($box['format'])) {
        return block_box_form($box);
      }
      break;

    case 'save':
      block_box_save($edit, $delta);
      break;

    case 'view':
      $block = db_fetch_object(db_query('SELECT * FROM {boxes} WHERE bid = %d', $delta));
      $data['subject'] = $block->title;
      $data['content'] = check_output($block->body, $block->format);
      return $data;
  }
}

function block_admin_save($edit) {
  foreach ($edit as $module => $blocks) {
    foreach ($blocks as $delta => $block) {
      db_query("UPDATE {blocks} SET region = %d, status = %d, weight = %d, throttle = %d WHERE module = '%s' AND delta = '%s'",
                $block['region'], $block['status'], $block['weight'], $block['throttle'], $module, $delta);
    }
  }

  return t('The block settings have been updated.');
}

/**
 * Update the 'blocks' DB table with the blocks currently exported by modules.
 *
 * @param $order_by php <a
 *   href="http://www.php.net/manual/en/function.array-multisort.php">array_multisort()</a>
 *   style sort ordering, eg. "weight", SORT_ASC, SORT_STRING.
 *
 * @return
 *   Blocks currently exported by modules, sorted by $order_by.
 */
function _block_rehash($order_by = array('weight')) {
  $result = db_query('SELECT * FROM {blocks} ');
  while ($old_block = db_fetch_object($result)) {
    $old_blocks[$old_block->module][$old_block->delta] = $old_block;
  }

  db_query('DELETE FROM {blocks} ');

  foreach (module_list() as $module) {
    $module_blocks = module_invoke($module, 'block', 'list');
    if ($module_blocks) {
      foreach ($module_blocks as $delta => $block) {
        $block['module'] = $module;
        $block['delta']  = $delta;
        if ($old_blocks[$module][$delta]) {
          $block['status'] = $old_blocks[$module][$delta]->status;
          $block['weight'] = $old_blocks[$module][$delta]->weight;
          $block['region'] = $old_blocks[$module][$delta]->region;
          $block['visibility'] = $old_blocks[$module][$delta]->visibility;
          $block['pages'] = $old_blocks[$module][$delta]->pages;
          $block['custom'] = $old_blocks[$module][$delta]->custom;
          $block['throttle'] = $old_blocks[$module][$delta]->throttle;
        }
        else {
          $block['status'] = $block['weight'] = $block['region'] = $block['custom'] = 0;
          $block['pages']   = '';
        }

        // reinsert blocks into table
        db_query("INSERT INTO {blocks} (module, delta, status, weight, region, visibility, pages, custom, throttle) VALUES ('%s', '%s', %d, %d, %d, %d, '%s', %d, %d)",
                  $block['module'], $block['delta'], $block['status'], $block['weight'], $block['region'], $block['visibility'], $block['pages'], $block['custom'], $block['throttle']);

        $blocks[] = $block;

        // build array to sort on
        $order[$order_by[0]][] = $block[$order_by[0]];
      }
    }
  }

  // sort
  array_multisort($order[$order_by[0]], $order_by[1] ? $order_by[1] : SORT_ASC, $order_by[2] ? $order_by[2] : SORT_REGULAR, $blocks);

  return $blocks;
}

/**
 * Prepare the main block administration form.
 */
function block_admin_display() {
  $blocks = _block_rehash();

  $header = array(t('Block'), t('Enabled'), t('Throttle'), t('Weight'), t('Region'), array('data' => t('Operations'), 'colspan' => 2));

  foreach ($blocks as $block) {
    if ($block['module'] == 'block') {
      $operation = l(t('delete'), 'admin/block/delete/'. $block['delta']);
    }
    else {
      $operation = '';
    }

    $rows[] = array($block['info'], array('data' => form_checkbox(NULL, $block['module'] .']['. $block['delta'] .'][status', 1, $block['status']), 'align' => 'center'), array('data' => form_checkbox(NULL, $block['module'] .']['. $block['delta'] .'][throttle', 1, $block['throttle'], NULL, module_exist('throttle') ? NULL : array('disabled' => 'disabled')), 'align' => 'center'), form_weight(NULL, $block['module'] .']['. $block['delta'] .'][weight', $block['weight']), form_radios(NULL, $block['module'] .']['. $block['delta'] .'][region', $block['region'], array(t('left'), t('right'))), l(t('configure'), 'admin/block/configure/'. $block['module'] .'/'. $block['delta']), $operation);
  }

  $output = theme('table', $header, $rows);
  $output .= form_submit(t('Save blocks'));

  return form($output, 'post', url('admin/block'));
}

function block_box_get($bid) {
  return db_fetch_array(db_query('SELECT * FROM {boxes} WHERE bid = %d', $bid));
}

/**
 * Menu callback; displays the block configuration form.
 */
function block_admin_configure($module = NULL, $delta = 0) {
  $edit = $_POST['edit'];
  $op = $_POST['op'];

  switch ($op) {
    case t('Save block'):
      db_query("UPDATE {blocks} SET visibility = %d, pages = '%s', custom = %d WHERE module = '%s' AND delta = '%s'", $edit['visibility'], $edit['pages'], $edit['custom'], $module, $delta);
      module_invoke($module, 'block', 'save', $delta, $edit);
      drupal_set_message('The block configuration has been saved.');
      cache_clear_all();
      drupal_goto('admin/block');

    default:
      // Always evaluates to TRUE, but a validation step may be added later.
      if (!$edit) {
        $edit = db_fetch_array(db_query("SELECT pages, visibility, custom FROM {blocks} WHERE module = '%s' AND delta = '%s'", $module, $delta));
      }

      // Module-specific block configurations.
      if ($settings = module_invoke($module, 'block', 'configure', $delta)) {
        $form = form_group(t('Block-specific settings'), $settings);
      }

      // Get the block subject for the page title.
      $info = module_invoke($module, 'block', 'list');
      drupal_set_title(t("'%name' block", array('%name' => $info[$delta]['info'])));

      // Standard block configurations.
      $group = form_radios(t('Show on specific pages'), 'visibility', $edit['visibility'], array(t('Show on every page except the listed pages.'), t('Show on only the listed pages.')));
      $group .= form_textarea(t('Pages'), 'pages', $edit['pages'], 40, 5, t("Enter one page per line as Drupal paths. The '*' character is a wildcard. Example paths are '<em>blog</em>' for the blog page and '<em>blog/*</em>' for every personal blog. '<em>&lt;front&gt;</em>' is the front page. "));

      $group .= form_radios(t('User options'), 'custom', $edit['custom'], array(t('Users may not turn on or off this block.'), t('Users may turn this block on or off, on by default.'), t('Users may turn this block on or off, off by default.')), t('Users can decide which blocks they want on or off on their account editing page.'));

      $form .= form_group(t('Visibility settings'), $group);

      $form .= form_submit(t('Save block'));

      print theme('page', form($form));
  }
}

/**
 * Menu callback; displays the block creation form.
 */
function block_box_add() {
  $edit = $_POST['edit'];
  $op = $_POST['op'];

  switch ($op) {
    case t('Save block'):
      block_box_save($edit);
      drupal_set_message(t('The new block has been added.'));
      drupal_goto('admin/block');

    default:
      $form = block_box_form();
      $form .= form_submit(t('Save block'));
      $output .= form($form);
  }

  print theme('page', $output);
}

/**
 * Menu callback; confirm and delete custom blocks.
 */
function block_box_delete($bid = 0) {
  $op = $_POST['op'];
  $box = block_box_get($bid);

  switch ($op) {
    case t('Delete'):
      db_query('DELETE FROM {boxes} WHERE bid = %d', $bid);
      drupal_set_message(t('The block %name has been deleted.', array('%name' => '<em>'. $box['info'] .'</em>')));
      cache_clear_all();
      drupal_goto('admin/block');

    default:
      $form = '<p>'. t('Are you sure you want to delete the block %name?', array('%name' => '<em>'. $box['info'] .'</em>')) ."</p>\n";
      $form .= form_submit(t('Delete'));
      $output = form($form);
  }

  print theme('page', $output);
}

function block_box_form($edit = array()) {
  $output = form_textfield(t('Block title'), 'title', $edit['title'], 50, 64, t('The title of the block as shown to the user.'));
  $output .= filter_form('format', $edit['format']);
  $output .= form_textarea(t('Block body'), 'body', $edit['body'], 70, 10, t('The content of the block as shown to the user.'));
  $output .= form_textfield(t('Block description'), 'info', $edit['info'], 50, 64, t('A brief description of your block.  Used on the <a href="%overview">block overview page</a>.', array('%overview' => url('admin/block'))));

  return $output;
}

function block_box_save($edit, $delta = NULL) {
  if (!filter_access($edit['format'])) {
    $edit['format'] = FILTER_FORMAT_DEFAULT;
  }

  if (isset($delta)) {
    db_query("UPDATE {boxes} SET title = '%s', body = '%s', info = '%s', format = %d WHERE bid = %d", $edit['title'], $edit['body'], $edit['info'], $edit['format'], $delta);
  }
  else {
    db_query("INSERT INTO {boxes} (title, body, info, format) VALUES  ('%s', '%s', '%s', %d)", $edit['title'], $edit['body'], $edit['info'], $edit['format']);
  }
}

/**
 * Menu callback; displays the block overview page.
 */
function block_admin() {
  $edit = $_POST['edit'];
  $op = $_POST['op'];

  if ($op == t('Save blocks')) {
    drupal_set_message(block_admin_save($edit));
    cache_clear_all();
    drupal_goto($_GET['q']);
  }
  print theme('page', block_admin_display());
}

/**
 * Implementation of hook_user().
 *
 * Allow users to decide which custom blocks to display when they visit
 * the site.
 */
function block_user($type, $edit, &$user, $category = NULL) {
  switch ($type) {
    case 'form':
      if ($category == 'account') {
        $result = db_query('SELECT * FROM {blocks} WHERE status = 1 AND custom != 0 ORDER BY weight, module, delta');

        while ($block = db_fetch_object($result)) {
          $data = module_invoke($block->module, 'block', 'list');
          if ($data[$block->delta]['info']) {
            $form .= form_checkbox($data[$block->delta]['info'], 'block]['. $block->module .']['. $block->delta, 1, isset($user->block[$block->module][$block->delta]) ? $user->block[$block->module][$block->delta] : ($block->custom == 1));
          }
        }

        if (isset($form)) {
          return array(array('title' => t('Block configuration'), 'data' => $form, 'weight' => 2));
        }
      }

      break;
    case 'validate':
      if (!$edit['block']) {
        $edit['block'] = array();
      }
      return $edit;
  }
}

/**
 * Return blocks available for current $user at $region.
 *
 * @param $region main|left|right
 *
 * @return array of block objects, indexed with <i>module</i>_<i>delta</i>
 *
 * @see <a href="http://drupal.org/node/1042" target="_top">[feature]
 *   Generic template design difficult w/o block region "look-ahead"</a>
 * @todo add a proper primary key (bid) to the blocks table so we don't have
 *   to mess around with this <i>module</i>_<i>delta</i> construct. currently,
 *   "blocks" has no primary key defined (bad)!
 */
function block_list($region) {
  global $user, $base_url;
  static $blocks = array();

  if (!isset($blocks[$region])) {
    $blocks[$region] = array();
    $result = db_query('SELECT * FROM {blocks} WHERE status = 1 '. ($region != 'all' ? 'AND region = %d ' : '') .'ORDER BY weight, module', $region == 'left' ? 0 : 1);

    while ($result && ($block = db_fetch_array($result))) {
      // Use the user's block visibility setting, if necessary
      if ($block['custom'] != 0) {
        if ($user->uid && isset($user->block[$block['module']][$block['delta']])) {
          $enabled = $user->block[$block['module']][$block['delta']];
        }
        else {
          $enabled = ($block['custom'] == 1);
        }
      }
      else {
        $enabled = TRUE;
      }

      // Match path if necessary
      if ($block['pages']) {
        $base = parse_url($base_url);
        $session = session_name() .'='. session_id();
        $url = str_replace(array($base['path'], '?'. $session), '', request_uri());
        $url = ereg_replace('^/(\?q=)?', '', $url);
        $regexp = '/^('. preg_replace(array('/(\r\n?|\n)/', '/\\\\\*/', '/(^|\|)\\\\<front\\\\>($|\|)/'), array('|', '.*', '\1\2'), preg_quote($block['pages'], '/')) .')$/';
        $matched = !($block['visibility'] xor preg_match($regexp, $url));
      }
      else {
        $matched = TRUE;
      }

      if ($enabled && $matched) {
        // Check the current throttle status and see if block should be displayed
        // based on server load.
        if (!($block['throttle'] && (module_invoke('throttle', 'status') > 0))) {
          $array = module_invoke($block['module'], 'block', 'view', $block['delta']);
          if (is_array($array)) {
            $block = array_merge($block, $array);
          }
        }
        if (isset($block['content']) && $block['content']) {
          $blocks[$region]["$block[module]_$block[delta]"] = (object) $block;
        }
      }
    }
  }
  return $blocks[$region];
}

?>