book.module

<?php
// $Id$

function book_node($field) {
  global $user;

  $info["name"] = t("book page");
  $info["description"] = t("A book is a collaborative writing effort: users can collaborate writing the pages of the book, positioning the pages in the right order, and reviewing or modifying pages previously written.  So when you have some information to share or when you read a page of the book and you didn't like it, or if you think a certain page could have been written better, you can do something about it.");

  return $info[$field];
}

function book_access($op, $node) {
  global $user;

  if ($op == "view") {
    /*
    ** Everyone can access all published book pages whether these pages
    ** are still waiting for approval or not.  We might not always want
    ** to display pages that are waiting for approval, but we take care
    ** of that problem in the book_view() function.
    */

    return $node->status;
  }

  if ($op == "create") {
    /*
    ** Only registered users can create book pages.  Given the nature
    ** of the book module this is considered to be a good/safe idea.
    */

    return $user->uid;
  }

  if ($op == "update") {
    /*
    ** Only registered users can update book pages.  Given the nature
    ** of the book module this is considered to be a good/safe idea.
    ** One can only upate a book page if there are no suggested updates
    ** of that page waiting for approval, when it is not a PHP-page and
    ** as long as the "create new revision"-bit is set.  That is, only
    ** updates that don't overwrite the current or pending information
    ** are allowed.
    */

    return $user->uid && !$node->moderate && !$node->format && $node->revision;
  }
}

function book_save($op, $node) {
  global $user, $REQUEST_URI;

  if ($op == "approve") {
    return array("status" => 1);
  }

  if ($op == "create") {
    if (user_access("adminster nodes")) {
      return array("format", "parent", "weight");
    }
    else {
      return array("format", "moderate" => 1, "parent", "promote" => 0, "status" => 1, "weight");
    }
  }

  if ($op == "decline") {
    return array("status" => 0);
  }

  if ($op == "update") {
    if (strstr($REQUEST_URI, "module.php?mod=node&op=edit")) {
      /*
      ** If a regular user updates a book page, we always create a new
      ** revision.  All new revisions have to be approved (moderation)
      ** and are not promoted by default.  See also: book_load().
      */

      return array("created" => time(), "format", "moderate" => 1, "parent", "promote" => 0, "score" => 0, "status" => 1, "users" => "", "revisions", "votes" => 0, "weight");
    }
    else if (user_access("adminster nodes")) {
      /*
      ** If a node administrator updates a book page, we don't create a
      ** new revision unless we are explicitly instructed to. If a node
      ** administrator updates a book page using the "update this book
      ** page"-link (like regular users do) then he'll be treated as a
      ** regular user.
      */

      return array("format", "parent", "weight");
    }
  }

}

function book_link($type, $node = 0, $main = 0) {
  if ($type == "page" && user_access("access content")) {
    $links[] = "<a href=\"module.php?mod=book\">". t("collaborative book") ."</a>";
  }

  if ($type == "admin" && user_access("administer nodes")) {
    $links[] = "<a href=\"admin.php?mod=book\">". t("collaborative book") ."</a>";
  }

  if ($type == "node" && $node->type == "book" && book_access("update", $node)) {
    $links[] = "<a href=\"module.php?mod=node&op=edit&id=$node->nid\">". t("update this book page") ."</a>";
  }

  return $links ? $links : array();
}

function book_load($node) {
  global $user, $REQUEST_URI;

  $book = db_fetch_object(db_query("SELECT format, parent, weight FROM book WHERE nid = '$node->nid'"));

  if (strstr($REQUEST_URI, "module.php?mod=node&op=edit")) {

    /*
    ** If a user is about to update a book page, we overload some
    ** fields to reflect the changes.  We use the $REQUEST_URI to
    ** dectect this as we don't want to interfer with updating a
    ** book page through the admin pages.  See also: book_save().
    */

    if ($user->uid) {
      $book->uid = $user->uid;
      $book->name = $user->name;
    }
    else {
      $book->uid = 0;
      $book->name = "";
    }
  }

  /*
  ** We set the revision field to indicate that we have to create
  ** a new revision when updating this book page.  We enable this
  ** always such that the "update this book page"-links appear.
  */

  $book->revision = 1;

  return $book;
}

function book_insert($node) {
  if (!user_access("administer nodes")) {
    $node->format = 0;
    $node->weight = 0;
  }

  db_query("INSERT INTO book (nid, format, parent, weight) VALUES ('$node->nid', '$node->format', '$node->parent', '$node->weight')");
}

function book_update($node) {
  if (!user_access("administer nodes")) {
    $node->format = 0;
    $node->weight = 0;
  }

  db_query("UPDATE book SET format = '$node->format', parent = '$node->parent', weight = '$node->weight' WHERE nid = '$node->nid'");
}

function book_delete(&$node) {
  db_query("DELETE FROM book WHERE nid = '$node->nid'");
}

function book_form(&$node, &$help, &$error) {
  global $user, $op;

  $output .= form_select(t("Parent"), "parent", $node->parent, book_toc(), t("The parent subject or category the page belongs in."));

  if ($node->format) {
    if ($op != t("Preview")) {
      $node->body = addslashes($node->body);
    }
  }
  else {
    if ($node->teaser) {
      $output .= form_textarea(t("Teaser"), "teaser", $node->teaser, 60, 5, $error["teaser"]);
    }
  }

  $output .= form_textarea(t("Body"), "body", $node->body, 60, 20, t("Allowed HTML tags") .": ". htmlspecialchars(variable_get("allowed_html", "")));
  $output .= form_textarea(t("Log message"), "history", $node->history, 60, 5, t("An explanation of the additions or updates being made to help the group understand your motivations."));

  if (user_access("administer nodes")) {
    $output .= form_select(t("Weight"), "weight", $node->weight, array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30), t("The heavier pages will sink and the lighter pages will be positioned nearer the top."));
    $output .= form_select("Type", "format", $node->format, array(0 => "HTML / text", 1 => "PHP"));
  }
  else {

    /*
    ** Carry out some explanation or submission guidelines:
    */

    $help = book_node("description");

    /*
    ** If a regular user updates a book page, we create a new revision
    ** authored by that user:
    */

    $output .= form_hidden("revision", 1);
  }

  return $output;
}

function book_node_link($node = 0) {
  global $user, $op, $edit;

  if ($node->type != "book") {

    if ($edit["nid"]) {
      $node = node_load(array("nid" => $edit["nid"]));
    }

    if ($op == t("Add to book outline")) {
      db_query("INSERT INTO book (nid, parent, weight) VALUES ('$node->nid', '". check_query($edit["parent"]) ."', '". check_query($edit["weight"]) ."')");
      $output .= status(t("added the node to the book."));
    }

    if ($op == t("Update book outline")) {
      db_query("UPDATE book SET parent = '". check_query($edit["parent"]) ."', weight = '". check_query($edit["weight"]) ."' WHERE nid = '$node->nid'");
      $output .= status(t("updated the book outline."));
    }

    if ($op == t("Remove from book outline")) {
      db_query("DELETE FROM book WHERE nid = '$node->nid'");
      $output .= status(t("removed the node form the book."));
    }

    $output .= "<h3>". t("Edit book outline") ."</h3>";

    if ($edit["nid"]) {
      $page = db_fetch_object(db_query("SELECT * FROM book WHERE nid = '$node->nid'"));

      $output .= form_select(t("Parent"), "parent", $page->parent, book_toc(), t("The parent subject or category the page belongs in."));
      $output .= form_select(t("Weight"), "weight", $page->weight, array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30), t("The heavier pages will sink and the lighter pages will be positioned nearer the top."));

      if ($page->nid) {
        $output .= form_submit(t("Update book outline"));
        $output .= form_submit(t("Remove from book outline"));
      }
      else {
        $output .= form_submit(t("Add to book outline"));
      }

    }
    else {
      $output .= form_submit(t("Edit book outline"));
    }

    $output .= form_hidden("nid", $node->nid);

    return form($output, "post", "admin.php?mod=book&op=outline");
  }
}

/*
** Return the the most recent revision that matches the specified
** conditions.
*/

function book_revision_load($page, $conditions = array()) {

  $revisions = array_reverse(node_revision_list($page));

  foreach ($revisions as $revision) {

    /*
    ** Extract the specified revision:
    */

    $node = node_revision_load($page, $revision);

    /*
    ** Check to see if the conditions are met:
    */

    $status = 1;

    foreach ($conditions as $key => $value) {
      if ($node->$key != $value) {
        $status = 0;
      }
    }

    if ($status) {
      return $node;
    }
  }
}

/*
** Return the path (call stack) to a certain book page.
*/

function book_location($node, $nodes = array()) {
  $parent = db_fetch_object(db_query("SELECT n.nid, n.title, b.parent FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE n.nid = '$node->parent'"));
  if ($parent->title) {
    $nodes = book_location($parent, $nodes);
    array_push($nodes, $parent);
  }
  return $nodes;
}

function book_body($node) {
  global $theme, $op;

  if ($node->format == 1) {
    /*
    ** Make sure only authorized users can preview PHP pages.
    */

    if ($op == t("Preview")) {
      if (user_access("adminster nodes")) {
        $node->body = stripslashes($node->body);  // see also book_form()
      }
      else {
        return;
      }
    }

    ob_start();
    eval($node->body);
    $output = ob_get_contents();
    ob_end_clean();
  }
  else {
    $output = check_output(filter($node->body), 1);
  }

  return $output;
}

function book_view($node, $main = 0) {
  global $theme, $mod;

  /*
  ** Always display the most recently approved revision of a node
  ** (if any) unless we have to display this page in the context of
  ** the moderation queue.
  */

  if ($node->moderate && $mod != "queue") {
    $revision = book_revision_load($node, array("moderate" => 0, "status" => 1));

    if ($revision) {
      $node = $revision;
    }
  }

  /*
  ** Extract the page body.  If body is dynamic (using PHP code), the body
  ** will be generated.
  */

  $node->body = book_body($node);

  /*
  ** Display the node.  If not displayed on the main page, we render
  ** the node as a page in the book with extra links to the previous
  ** and the next page.
  */

  if ($main) {
    $theme->node($node, $main);
  }
  else {
    /*
    ** Construct the "next" and "previous" links:
    */

    if ($node->nid && $node->parent) {
      $next = db_fetch_object(db_query("SELECT n.nid, n.title FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE n.status = 1 AND b.parent = '$node->parent' AND (b.weight > '$node->weight' OR (b.weight = '$node->weight' AND n.title > '". check_query($node->title) ."')) AND (n.moderate = 0 OR n.revisions != '') ORDER BY b.weight ASC, n.title ASC"));
      $prev = db_fetch_object(db_query("SELECT n.nid, n.title FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE n.status = 1 AND b.parent = '$node->parent' AND (b.weight < '$node->weight' OR (b.weight = '$node->weight' AND n.title < '". check_query($node->title) ."')) AND (n.moderate = 0 OR n.revisions != '') ORDER BY b.weight DESC, n.title DESC"));
    }

    $output .= "<table border=\"0\" cellpadding=\"1\" cellspacing=\"1\" width=\"100%\">";

    if ($node->title) {
      foreach (book_location($node) as $level) {
        $location .= "$indent <a href=\"node.php?id=$level->nid\">$level->title</a><br />";
        $indent .= "-";
      }

      $output .= " <tr><td colspan=\"3\">$location</td></tr>";
      $output .= " <tr><td colspan=\"3\"><hr /></td></tr>";
      $output .= " <tr><td colspan=\"3\"><b><big>". check_output($node->title) ."</big></b>". ($node->body ? "<br /><small><i>". sprintf(t("Last updated by %s on %s"), format_name($node), format_date($node->created)) ."</i></small> " : "") ."</td></tr>";
    }

    if ($node->body) {
      $output .= " <tr><td colspan=\"3\"><br />$node->body</td></tr>";
    }

    if ($node->nid) {
      $output .= " <tr><td colspan=\"3\"><br />". book_tree($node->nid) ."</td></tr>";
    }

    $output .= " <tr><td colspan=\"3\"><hr /></td></tr>";
    $output .= " <tr><td align=\"left\" width=\"33%\">". ($prev ? "<a href=\"node.php?id=$prev->nid\">". t("previous") ."</a>" : t("previous")) ."</td><td align=\"center\" width=\"34%\"><a href=\"module.php?mod=book\">index</a></td><td align=\"right\" width=\"33%\">". ($next ? "<a href=\"node.php?id=$next->nid\">". t("next") ."</a>" : t("next")) ."</td></tr>";
    $output .= " <tr><td align=\"left\" width=\"33%\">". ($prev ? "<small>". check_output($prev->title) ."</small>" : "&nbsp;") ."</td><td align=\"center\" width=\"34%\">". ($node->parent ? "<a href=\"node.php?id=$node->parent\">". t("up") ."</a>" : t("up")) ."</td><td align=\"right\" width=\"33%\">". ($next ? "<small>". check_output($next->title) ."</small>" : "&nbsp;") ."</td></tr>";
    $output .= " <tr><td colspan=\"3\"><hr /></td></tr>";
    $output .= " <tr><td colspan=\"3\" align=\"right\"><div style=\"margin: 10 10 10 10;\">". $theme->links(link_node($node, $main)) ."</div></td></tr>";
    $output .= "</table>";

    $theme->box(t("Handbook"), $output);
  }
}

function book_toc_recurse($nid, $indent, $toc, $children) {

  if ($children[$nid]) {
    foreach ($children[$nid] as $foo => $node) {
      $toc[$node->nid] = "$indent $node->title";
      $toc = book_toc_recurse($node->nid, "$indent--", $toc, $children);
    }
  }

  return $toc;
}

function book_toc($parent = "", $indent = "", $toc = array()) {

  $result = db_query("SELECT n.nid, n.title, b.parent FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE n.type = 'book' AND n.status = '1' ORDER BY b.weight, n.title");

  while ($node = db_fetch_object($result)) {
    $list = $children[$node->parent] ? $children[$node->parent] : array();
    array_push($list, $node);
    $children[$node->parent] = $list;
  }

  /*
  ** If the user is an administrator, add the root node; only
  ** administrators can start new books.
  */

  if (user_access("administer nodes")) {
    $toc[0] = "<root>";
  }

  /*
  ** Iterate root book nodes:
  */

  $toc = book_toc_recurse(0, $indent, $toc, $children, $titles);

  return $toc;
}

function book_tree($parent = "", $depth = 0) {

  if ($depth < 3) {

    /*
    ** Select all child nodes and render them into a table of contents:
    */

   $result = db_query("SELECT n.nid FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE b.parent = '$parent' AND (n.moderate = 0 OR n.revisions != '') ORDER BY b.weight, n.title");

     while ($page = db_fetch_object($result)) {
       // load the node:
       $node = node_load(array("nid" => $page->nid));

       // take the most recent approved revision:
       if ($node->moderate) {
         $node = book_revision_load($node, array("moderate" => 0, "status" => 1));
       }

       if ($node) {
         // output the content:
         $output .= "<li><a href=\"node.php?id=$node->nid\">". check_output($node->title) ."</a></li>";

         // build the sub-tree of each child:
         $output .= book_tree($node->nid, $depth + 1);
       }
     }

     $output = "<ul>$output</ul>";

  }

  return $output;
}

function book_render() {
  global $theme;

  $result = db_query("SELECT n.nid FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE b.parent = 0 AND n.status = 1 AND (n.moderate = 0 OR n.revisions != '') ORDER BY b.weight");

  while ($page = db_fetch_object($result)) {
    // load the node:
    $node = node_load(array("nid" => $page->nid));

    // take the most recent approved revision:
    if ($node->moderate) {
      $node = book_revision_load($node, array("moderate" => 0, "status" => 1));
    }

    if ($node) {
      // output the content:
      $output .= "<dt><a href=\"node.php?id=$node->nid\">". check_output($node->title) ."</a></dt><dd>". book_body($node) ."<br /><br /></dd>";
    }
  }

  $theme->header();
  $theme->box(t("Handbook"), "<dl>$output</dl>");
  $theme->footer();
}

function book_page() {
  global $op, $id, $theme;

  if (user_access("access content")) {
    switch ($op) {
      case "feed":
        print book_export_html($id, $depth = 1);
        break;
      default:
        book_render();
    }
  }
  else {
    $theme->header();
    $theme->box(t("Access denied"), message_access());
    $theme->footer();
  }
}

function book_export_html($id = "", $depth = 1) {
  $result = db_query("SELECT n.nid FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE n.status = 1 AND n.nid = '". check_input($id) ." AND (n.moderate = 0 OR n.revisions != '')'");

  while ($page = db_fetch_object($result)) {
    // load the node:
    $node = node_load(array("nid" => $page->nid));

    // take the most recent approved revision:
    if ($node->moderate) {
      $node = book_revision_load($node, array("moderate" => 0, "status" => 1));
    }

    if ($node) {
      // output the content:
      $output .= "<h$depth>". check_output($node->title) ."</h$depth>";

      if ($node->body) {
        $output .= "<ul>". book_body($node) ."</ul>";
      }
    }
  }

  $output .= book_export_html_recurse($id, $depth);

  return $output;
}

function book_export_html_recurse($parent = "", $depth = 1) {
  $result = db_query("SELECT n.nid FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE n.status = 1 AND b.parent = '$parent' AND (n.moderate = 0 OR n.revisions != '') ORDER BY b.weight");

  while ($page = db_fetch_object($result)) {
    // load the node:
    $node = node_load(array("nid" => $page->nid));

    // take the most recent approved revision:
    if ($node->moderate) {
      $node = book_revision_load($node, array("moderate" => 0, "status" => 1));
    }

    if ($node) {
      // output the content:
      $output .= "<h$depth>". check_output($node->title) ."</h$depth>";

      if ($node->body) {
        $output .= "<ul>". book_body($node) ."</ul>";
      }

      $output .= book_export_html_recurse($node->nid, $depth + 1);
    }
  }

  return $output;
}

function book_admin_view_line($node, $depth = 0) {

  /*
  ** Extract the revision number:
  */

  if ($list = node_revision_list($node)) {
    $revision = end($list);
  }
  else {
    $revision = 0;
  }

  /*
  ** Diplay the book page:
  */

  $output .= "<tr>";
  $output .= " <td><div style=\"padding-left: ". (25 * $depth) ."px;\"><a href=\"node.php?id=$node->nid\">". check_output($node->title) ."</a></div></td>";
  $output .= " <td align=\"center\">$revision</td>";
  $output .= " <td><a href=\"admin.php?mod=node&op=edit&id=$node->nid\">". t("edit page") ."</td>";
  $output .= " <td><a href=\"admin.php?mod=node&op=delete&id=$node->nid\">". t("delete page") ."</td>";
  $output .= "</tr>";

  return $output;
}

function book_admin_view_book($nid, $depth = 1) {
  $weight = array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30);

  $result = db_query("SELECT n.nid FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE b.parent = '$nid' ORDER BY b.weight, n.title");

  while ($node = db_fetch_object($result)) {
    $node = node_load(array("nid" => $node->nid));
    $output .= book_admin_view_line($node, $depth);
    $output .= book_admin_view_book($node->nid, $depth + 1);
  }

  return $output;
}

function book_admin_view($nid, $depth = 0) {

  $node = node_load(array("nid" => $nid));

  $output .= "<h3>". check_output($node->title) ."</h3>";
  $output .= "<table border=\"1\" cellpadding=\"2\" cellspacing=\"2\">";
  $output .= " <tr><th>title</th><th>rev</th><th colspan=\"2\">operations</th></tr>";
  $output .= book_admin_view_line($node);
  $output .= book_admin_view_book($nid);
  $output .= "</table>";

  return $output;
}

function book_admin_orphan() {

  $result = db_query("SELECT n.nid, n.title, b.parent FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE n.type = 'book'");

  while ($page = db_fetch_object($result)) {
    $pages[$page->nid] = $page;
  }

  $output .= "<table border=\"1\" cellpadding=\"2\" cellspacing=\"2\">";
  $output .= " <tr><th>title</th><th colspan=\"2\">operations</th></tr>";
  foreach ($pages as $nid => $node) {
    if ($node->parent && empty($pages[$node->parent])) {
      $output .= "<tr><td><a href=\"node.php?id=$node->nid\">". check_output($node->title) ."</a></td><td><a href=\"admin.php?mod=node&op=edit&id=$node->nid\">". t("edit page") ."</td><td><a href=\"admin.php?mod=node&op=delete&id=$node->nid\">". t("delete page") ."</td>";
    }
  }
  $output .= "</table>";

  return $output;
}

function book_admin_links() {
  $result = db_query("SELECT n.nid, n.title FROM node n LEFT JOIN book b ON n.nid = b.nid WHERE b.parent = 0 ORDER BY b.weight, n.title");

  while ($book = db_fetch_object($result)) {
    $links[] = "<a href=\"admin.php?mod=book&op=view&id=$book->nid\">". t("book") .": <i>". check_output($book->title) ."</i></a>";
  }

  return $links;
}

function book_admin() {
  global $id, $op;

  if (user_access("administer nodes")) {

    /*
    ** Compile a list of the administrative links:
    */

    $links = book_admin_links();
    $links[] = "<a href=\"admin.php?mod=book&op=orphan\">". t("orphan pages") ."</a>";

    print "<small>". implode(" &middot; ", $links) ."</small><hr />";

    switch ($op) {
      case t("Edit book outline"):
      case t("Add to book outline"):
      case t("Remove from book outline"):
      case t("Update book outline"):
        print book_node_link();
        break;
      case "orphan":
        print book_admin_orphan();
        break;
      case "view":
        print book_admin_view($id);
        break;
      default:
    }
  }
}

?>