block.module

<?php
// $Id$

function block_help() {
  $output .= "<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 using either static HTML or dynamic PHP content.</p>";
  $output .= "<p>Which sidebar each block appears in depends on which theme you're using (some are left-only, some right, some both), and also on the settings in block management.</p><p>Whether a block is visible in the first place depends on three things:</p><ul><li>It must have its \"enabled\" box checked in block management.</li><li>If it has its \"custom\" box checked in block management, the user must have chosen to display it in their user preferences.</li><li>If the \"path\" field in block management is set, the visitor must be on a page that matches the path specification (more on this later).</li></ul>";
  $output .= "<p>The block management screen also lets you specify the vertical sort-order of the blocks within a sidebar. You do this by assigning a <b>weight</b> to each block. Lighter blocks (smaller weight) \"float up\" towards the top of the sidebar. Heavier ones \"sink down\" towards the bottom of it. Once you've positioned things just so, you can preview what the layout will look like in different types of themes by clicking the preview placement link in the menu to the left.</p>";
  $output .= "<p>The path setting lets you define on which pages you want a specific block to be shown. If you leave the path blank it will show on all pages. The path uses a regular expression syntax so remember to escape special characters!";
  $output .= "<h3>Custom Blocks</h3>";
  $output .= "<p>A custom block is a block that contains admin-supplied HTML, text or PHP content (as opposed to being generated automatically by a module). Each custom block consists of a title, a description, and a body of text, HTML, or PHP code which can be as long as you wish. The Drupal engine will 'render' the content of the custom block.</p>";
  $output .= "<h4>PHP in custom blocks</h4>";
  $output .= "<p>If you know how to script in PHP, Drupal gives you the power to embed any script you like inside a block. It will be executed at page view and dynamically embedded into the page. This gives you amazing flexibility and power, but of course with that comes danger and insecurity if you don't write good code. If you are not familiar with PHP, SQL or with the site engine, avoid experimenting with PHP custom blocks because you can corrupt your database or render your site insecure or even unusable! If you don't plan to do fancy stuff with custom blocks then you're probably better off with straight HTML.</p>";
  $output .= "<p>Remember that the code within each PHP custom block must be valid PHP code - including things like correctly terminating statements with a semicolon so that the parser won't die. It is highly recommended that you develop your cusom blocks separately using a simple test script on top of a test database before migrating to your production environment.</p>";
  $output .= "<p>Notes:</p><ul><li>You can use global variables, such as configuration parameters, within the scope of a PHP box but remember that variables which have been given values in a PHP box will retain these values in the engine or module afterwards.</li><li>register_globals is now set to <b>off</b> by default. If you need form information you need to get it from the \"superglobals\" \$_POST, \$_GET, etc.</li><li>You can use the <code>return</code> statement to return the actual content for your block as well.</li></ul>";
  $output .= "<p>A basic example:</p>";
  $output .= "<blockquote><p>You want to have a box with the title \"Welcome\" that you use to greet your visitors. The content for this box could be created by going:</p>";
  $output .= "<pre>
  return t(\"Welcome visitor, ... welcome message goes here ...\");
</pre>";
  $output .= "<p>If we are however dealing with a registered user, we can customize the message by using:</p>";
  $output .= "<pre>
  if (\$user->uid) {
    return t(\"Welcome \$user->name, ... welcome message goes here ...\");
  }
  else {
    return t(\"Welcome visitor, ... welcome message goes here ...\");
  }";
  $output .= "</pre></blockquote>";
  $output .= "<p>For more in-depth examples, we recommend that you check the existing boxes and use them as a starting point.</p>";
  return t($output);

}

function block_system($field){
  $system["description"] = t("Controls the boxes that are displayed around the main content.");
  return $system[$field];
}

function block_perm() {
  return array("administer blocks");
}

function block_link($type) {
  if ($type == "admin" && user_access("administer blocks")) {
   $help["block"] = t("Blocks are the boxes visible in the side bars on the left- and right-hand side of the web site, depending on the choosen theme.  They are created by <b>active</b> Drupal modules.  In order to view a block it must be enabled. You can assign the block's placement by giving it a region and a weight. The region specifies which side of the page the block is on, and the weight sorts blocks within a region. Lighter (smaller weight value) blocks \"float up\" towards the top of the page. The path setting is a mask which lets you define on which pages you want the specific block to be shown. The custom checkbox lets your users hide the block from their account setting page. You can also create your own blocks, where you specify the content of the block rather than it being generated by a module (you can even use PHP in these). You can create one of these by clicking the %createblock link in the menu to the left. Edit and delete links will become active below for these customized blocks.", array("%createblock" => l(t("create new block"), "admin/block/add")));
    $help["create"] = t("Here you can create a custom content block. Once you have created this block you must make it active, and give it a place on the page using <a href=\"%overview\">block management</a>. The title is used when displaying the block. The description is used in the \"block\" column on the <a href=\"%overview\">block management</a> page. If you are going to place PHP code in the block, and you have <b>create PHP content</b> permission (see <a href=\"%permission\">user management >> user permissions</a>) you <B>must</b> change the type to PHP to make your code active.", array("%overview" => url("admin/block"), "%permission" => url("admin/user/permission")));
    $help["preview"] = t("This page helps show you the placement of your blocks in different themes. The numbers are the weight of each block, which is used to sort them within the sidebars.");

    menu("admin/block", "block management", "block_admin", $help["block"], 3);
    menu("admin/block/add", "create new block", "block_admin", $help["create"], 2);
    menu("admin/block/preview", "preview placement", "block_admin", $help["preview"], 3);
    menu("admin/block/help", "help", "block_help", NULL, 9);
  }
}

function block_block($op = "list", $delta = 0) {
  if ($op == "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;
  }
  else {
    $block = db_fetch_object(db_query("SELECT * FROM boxes WHERE bid = %d", $delta));
    $data["subject"] = $block->title;
    $data["content"] = ($block->type == 1) ? eval($block->body) : $block->body;
    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, custom = %d, path = '%s', weight = %d WHERE module = '%s' AND delta = '%s'",
                $block["region"], $block["status"], $block["custom"], $block["path"], $block["weight"], $module, $delta);
    }
  }

  return t("the block settings have been updated.");
}

/**
 * update blocks db table with blocks currently exported by modules
 *
 * @param   array   $order_by   php array_multisort() style sort ordering, eg. "weight", SORT_ASC, SORT_STRING. see {@link http://www.php.net/manual/en/function.array-multisort.php}
 * @return  array   blocks currently exported by modules, sorted by $order_by
 * @access  private
 */
function _block_rehash($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["path"]   = $old_blocks[$module][$delta]->path;
          $block["custom"] = $old_blocks[$module][$delta]->custom;
        }
        else {
          $block["status"] = $block["weight"] = $block["region"] = $block["custom"] = 0;
          $block["path"]   = "";
        }

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

        $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;
}

function block_admin_display() {

  $blocks = _block_rehash();

  $header = array(t("block"), t("enabled"), t("custom"), t("weight"), t("region"), t("path"), array("data" => "operations", "colspan" => 2));

  foreach ($blocks as $block) {
    if ($block["module"] == "block") {
      $edit = l(t("edit"), "admin/block/edit/". $block["delta"]);
      $delete = l(t("delete"), "admin/block/delete/". $block["delta"]);
    }
    else {
      $edit = "";
      $delete = "";
    }

    $rows[] = array($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"]."][custom", 1, $block["custom"]), "align" => "center"), form_weight(NULL, $block["module"]."][".$block["delta"]."][weight", $block["weight"]), form_select(NULL, $block["module"]."][".$block["delta"]."][region", $block["region"], array("left", "right")), form_textfield(NULL, $block["module"]."][".$block["delta"]."][path", $block["path"], 10, 255), $edit, $delete);
  }

  $output = table($header, $rows);
  $output .= form_submit("Save blocks");

  print form($output);
}

function block_admin_preview() {

  $result = db_query("SELECT * FROM blocks WHERE status > 0 AND region = 0 ORDER BY weight");
  $lblocks .= "<table border=\"0\" cellpadding=\"2\" cellspacing=\"2\">\n";
  while ($block = db_fetch_object($result)) {
    $block_data = module_invoke($block->module, "block", "list");
    $name = $block_data[$block->delta]["info"];
    $lblocks .= " <tr><td nowrap=\"nowrap\">". ($block->status == 2 ? "<b>$name</b>" : $name) ."</td><td>$block->weight</td></tr>\n";
  }
  $lblocks .= "</table>\n";

  $result = db_query("SELECT * FROM blocks WHERE status > 0 AND region = 1 ORDER BY weight");
  $rblocks .= "<table border=\"0\" cellpadding=\"2\" cellspacing=\"2\">\n";
  while ($block = db_fetch_object($result)) {
    $block_data = module_invoke($block->module, "block", "list");
    $name = $block_data[$block->delta]["info"];
    $rblocks .= " <tr><td nowrap=\"nowrap\">". ($block->status == 2 ? "<b>$name</b>" : $name) ."</td><td>$block->weight</td></tr>\n";
  }
  $rblocks .= "</table>\n";

  $output .= "<h3>". t("Themes with both left and right sidebars") .":</h3>\n";
  $output .= "<table border=\"1\" cellpadding=\"2\" cellspacing=\"2\">\n";
  $output .= " <tr><td align=\"center\" colspan=\"3\">header</td></tr>\n";
  $output .= " <tr><td>\n". ($lblocks ? $lblocks : "&nbsp;") ."</td><td width=\"300\">&nbsp;</td><td>\n". ($rblocks ? $rblocks : "&nbsp;") ."</td></tr>\n";
  $output .= " <tr><td align=\"center\" colspan=\"3\">footer</td></tr>\n";
  $output .= "</table>\n";

  $result = db_query("SELECT * FROM blocks WHERE status > 0 ORDER BY weight");
  $blocks .= "<table border=\"0\" cellpadding=\"2\" cellspacing=\"2\">\n";
  while ($block = db_fetch_object($result)) {
    $block_data = module_invoke($block->module, "block", "list");
    $name = $block_data[$block->delta]["info"];
    $blocks .= " <tr><td nowrap=\"nowrap\">". ($block->status == 2 ? "<b>$name</b>" : $name) ."</td><td>$block->weight</td></tr>\n";
  }
  $blocks .= "</table>\n";

  $output .= "<h3>". t("Themes with right-sidebar only") .":</h3>\n";
  $output .= "<table border=\"1\" cellpadding=\"2\" cellspacing=\"2\">\n";
  $output .= " <tr><td align=\"center\" colspan=\"2\">header</td></tr>\n";
  $output .= " <tr><td width=\"400\">&nbsp;</td><td>\n". ($blocks ? $blocks : "&nbsp;") ."</td></tr>\n";
  $output .= " <tr><td align=\"center\" colspan=\"2\">footer</td></tr>\n";
  $output .= "</table>\n";

  $output .= "<h3>". t("Themes with left-sidebar only") .":</h3>\n";
  $output .= "<table border=\"1\" cellpadding=\"2\" cellspacing=\"2\">\n";
  $output .= " <tr><td align=\"center\" colspan=\"2\">header</td></tr>\n";
  $output .= " <tr><td>\n". ($blocks ? $blocks : "&nbsp;") ."</td><td width=\"400\">&nbsp;</td></tr>\n";
  $output .= " <tr><td align=\"center\" colspan=\"2\">footer</td></tr>\n";
  $output .= "</table>\n";

  print $output;
}

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

function block_box_form($edit = array()) {
  $type = array(0 => "HTML", 1 => "PHP");

  $form = form_textfield("Title", "title", $edit["title"], 50, 64);
  $form .= form_textfield("Description", "info", $edit["info"], 50, 64);
  $form .= form_textarea("Body", "body", $edit["body"], 70, 10);
  if (user_access("create php content")) {
    $form .= form_select("Type", "type", $edit["type"], $type);
  }

  if ($edit["bid"]) {
    $form .= form_hidden("bid", $edit["bid"]);
  }

  $form .= form_submit("Save block");

  print form($form);
}

function block_box_save($edit) {
  if (!user_access("create PHP content")) {
    $edit["type"] = 0;
  }

  if ($edit["bid"]) {
    db_query("UPDATE boxes SET title = '%s', body = '%s', info = '%s', type = %d WHERE bid = %d", $edit["title"], $edit["body"], $edit["info"], $edit["type"], $edit["bid"]);
    return t("the block has been updated.");
  }
  else {
    db_query("INSERT INTO boxes (title, body, info, type) VALUES  ('%s', '%s', '%s', %d)", $edit["title"], $edit["body"], $edit["info"], $edit["type"]);
    return t("the new block has been added.");
  }
}

function block_box_delete($bid) {
  if ($bid) {
    db_query("DELETE FROM boxes WHERE bid = %d", $bid);
    return t("the block has been deleted.");
  }
}

function block_admin() {
  $op = $_POST["op"];
  $edit = $_POST["edit"];

  if (user_access("administer blocks")) {

    if (empty($op)) {
      $op = arg(2);
    }

    switch ($op) {
      case "preview":
        block_admin_preview();
        break;
      case "add":
        block_box_form();
        break;
      case "edit":
        block_box_form(block_box_get(arg(3)));
        break;
      case "delete":
        print status(block_box_delete(arg(3)));
        cache_clear_all();
        block_admin_display();
        break;
      case "Save block":
        print status(block_box_save($edit));
        cache_clear_all();
        block_admin_display();
        break;
      case "Save blocks":
        print status(block_admin_save($edit));
        cache_clear_all();
        // fall through
      default:
        block_admin_display();
    }
  }
  else {
    print message_access();
  }
}

function block_user($type, &$edit, &$user) {
  switch ($type) {
    case "register_form":
      $result = db_query("SELECT * FROM blocks WHERE custom = %d ORDER BY module, delta", 1);

      while ($block = db_fetch_object($result)) {
        $form .= form_hidden("block][$block->module][$block->delta", $block->status);
      }

      return $form;
    case "edit_form":
      $result = db_query("SELECT * FROM blocks WHERE custom = %d ORDER BY module, delta", 1);

      while ($block = db_fetch_object($result)) {
        $data = module_invoke($block->module, "block", "list");
        if ($data[$block->delta]["info"]) {
          $form .= "<tr><td>".$data[$block->delta]["info"]."</td><td>". form_checkbox(NULL, "block][$block->module][$block->delta", 1, $user->block[$block->module][$block->delta]) ."</td></tr>\n";
        }
      }

      if (isset($form)) {
        return form_item(t("Block configuration"), "<table border=\"0\" cellpadding=\"2\" cellspacing=\"2\">". $form ."</table>", t("Enable the blocks you would like to see displayed in the side bars."));
      }

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

?>