Add Item_Model::viewable() which we can use to restrict any query to

just items viewable by the active user.  Ie:

  ORM::factory("item")
    ->where("name", "foo")
    ->find_all()

Would get all items with the name "foo".

  ORM::factory("item")
    ->viewable()
    ->where("name", "foo")
    ->find_all()

Restricts it to just the set of items that the user is allowed to see.

core/controllers/albums.php

@@ -24,27 +24,26 @@ class Albums_Controller extends Items_Controller {
    */
   public function _show($item) {
     if (!access::can("view", $item)) {
-      return Kohana::show_404();
+      Kohana::show_404();
     }
 
     $theme_name = module::get_var("core", "active_theme", "default");
     $page_size = module::get_var("core", "page_size", 9);
-
-    $template = new Theme_View("page.html", "album", $theme_name);
-
     $page = $this->input->get("page", "1");
-
-    $template->set_global('page_size', $page_size);
-    $template->set_global('item', $item);
+    $children_count = $item->viewable()->children_count();
+    $offset = ($page-1) * $page_size;
 
     // Make sure that the page references a valid offset
-    $children_count = $item->children_count();
-    while (($offset = ($page - 1) * $page_size) > $children_count && $page != 1) {
-      $page--;
+    if ($page < 1 || $page > ceil($children_count / $page_size)) {
+      Kohana::show_404();
     }
-    $template->set_global('children', $item->children($page_size, $offset));
-    $template->set_global('children_count', $children_count);
-    $template->set_global('parents', $item->parents());
+
+    $template = new Theme_View("page.html", "album", $theme_name);
+    $template->set_global("page_size", $page_size);
+    $template->set_global("item", $item);
+    $template->set_global("children", $item->viewable()->children($page_size, $offset));
+    $template->set_global("children_count", $children_count);
+    $template->set_global("parents", $item->parents());
     $template->content = new View("album.html");
 
     print $template;

core/models/item.php

@@ -20,9 +20,25 @@
 class Item_Model extends ORM_MPTT {
   protected $children = 'items';
   private $relative_path = null;
+  private $view_restrictions = array();
 
   var $rules = array();
 
+  /**
+   * Add a set of restrictions to any following queries to restrict access only to items
+   * viewable by the active user.
+   * @chainable
+   */
+  public function viewable() {
+    if (empty($this->view_restrictions)) {
+      foreach (user::group_ids() as $id) {
+        $this->view_restrictions["view_$id"] = access::ALLOW;
+      }
+    }
+    $this->where($this->view_restrictions);
+    return $this;
+  }
+
   /**
    * Is this item an album?
    * @return true if it's an album

modules/tag/controllers/tags.php

@@ -23,15 +23,20 @@ class Tags_Controller extends REST_Controller {
   public function _show($tag) {
     $theme_name = module::get_var("core", "active_theme", "default");
     $page_size = module::get_var("core", "page_size", 9);
+    $page = $this->input->get("page", "1");
+    $children_count = $tag->items_count();
+    $offset = ($page-1) * $page_size;
+
+    // Make sure that the page references a valid offset
+    if ($page < 1 || $page > ceil($children_count / $page_size)) {
+      Kohana::show_404();
+    }
 
     $template = new Theme_View("page.html", "tag", $theme_name);
-
-    $page = $this->input->get("page", "1");
-
     $template->set_global('page_size', $page_size);
     $template->set_global('tag', $tag);
-    $template->set_global('children', $tag->items($page_size, ($page-1) * $page_size));
-    $template->set_global('children_count', $tag->count);
+    $template->set_global('children', $tag->items($page_size, $offset));
+    $template->set_global('children_count', $children_count);
     $template->content = new View("tag.html");
 
     print $template;

modules/tag/models/tag.php

@@ -24,14 +24,15 @@ class Tag_Model extends ORM {
     "name" => "required|length[4,32]");
 
   /**
-   * Return all items associated with this tag.
-   * @param string   $type   the type of item (album, photo)
+   * Return all viewable items associated with this tag.
    * @param integer  $limit  number of rows to limit result to
    * @param integer  $offset offset in result to start returning rows from
+   * @param string   $type   the type of item (album, photo)
    * @return ORM_Iterator
    */
   public function items($limit=null, $offset=0, $type=null) {
     $model = ORM::factory("item")
+      ->viewable()
       ->join("items_tags", "items.id", "items_tags.item_id")
       ->where("items_tags.tag_id", $this->id);
     if ($type) {
@@ -39,4 +40,17 @@ class Tag_Model extends ORM {
     }
     return $model->find_all($limit, $offset);
  }
+
+  /**
+   * Return the count of all viewable items associated with this tag.
+   * @param string   $type   the type of item (album, photo)
+   * @return integer
+   */
+  public function items_count($type=null) {
+    return ORM::factory("item")
+      ->viewable()
+      ->join("items_tags", "items.id", "items_tags.item_id")
+      ->where("items_tags.tag_id", $this->id)
+      ->count_all();
+ }
 }