Stay on the right page when we navigate up in the breadcrumb.

Introduce a "show" parameter which contains the id of the item that we
want to show when we go to the parent's page.

2 files changed, 25 insertions, 0 deletions

diff --git a/core/controllers/albums.php b/core/controllers/albums.php
index 668e868a..7f78303e 100644
--- a/core/controllers/albums.php
+++ b/core/controllers/albums.php
@@ -26,6 +26,18 @@ class Albums_Controller extends Items_Controller {
     access::required("view", $album);
 
     $page_size = module::get_var("core", "page_size", 9);
+    $show = $this->input->get("show");
+
+    if ($show) {
+      $index = $album->get_position($show);
+      $page = ceil($index / $page_size);
+      if ($page == 1) {
+        url::redirect("albums/$album->id");
+      } else {
+        url::redirect("albums/$album->id?page=$page");
+      }
+    }
+
     $page = $this->input->get("page", "1");
     $children_count = $album->viewable()->children_count();
     $offset = ($page-1) * $page_size;
diff --git a/core/models/item.php b/core/models/item.php
index ffdaa7e9..6f56e726 100644
--- a/core/models/item.php
+++ b/core/models/item.php
@@ -234,4 +234,17 @@ class Item_Model extends ORM_MPTT {
 
     return model_cache::get("item", $this->album_cover_item_id);
   }
+
+  /**
+   * Find the position of the given child id in this album.  The resulting value is 1-indexed, so
+   * the first child in the album is at position 1.
+   */
+  public function get_position($child_id) {
+    // Right now we only sort by id ascending, so bake that assumption in here.
+    // @todo fix this when we introduce sort orders.
+    return ORM::factory("item")
+      ->where("parent_id", $this->id)
+      ->where("id <=", $child_id)
+      ->count_all();
+  }
 }