Add unittest and caching for ORM_MTPP::descendants

2 files changed, 48 insertions, 12 deletions

diff --git a/core/libraries/ORM_MPTT.php b/core/libraries/ORM_MPTT.php
index c9c29805..88e79194 100644
--- a/core/libraries/ORM_MPTT.php
+++ b/core/libraries/ORM_MPTT.php
@@ -37,6 +37,7 @@ class ORM_MPTT_Core extends ORM {
   private $parents = null;
   private $children = null;
   private $children_count = null;
+  private $descendants = array();
   private $descendants_count = array();
 
   function __construct($id=null) {
@@ -143,20 +144,19 @@ class ORM_MPTT_Core extends ORM {
    * @return object ORM_Iterator
    */
   function descendants($limit=NULL, $offset=0, $type=null) {
-    // @todo create a unit test
-    // @todo set up caching in an array; using type=all allows us to cache as decendents[$type]
-    // @todo needs to take into account the offset and limit as well
-    $this->where("left >=", $this->left)
-         ->where("right <=", $this->right);
-    if ($type) {
-      $this->where("type", $type);
-    }
+    if (!isset($this->descendants[$type][$offset])) {
+      $this->where("left >", $this->left)
+        ->where("right <=", $this->right);
+      if ($type) {
+        $this->where("type", $type);
+      }
 
-    // @todo: make the order column data driven
-    $this->orderby("id", "ASC");
+      // @todo: make the order column data driven
+      $this->orderby("id", "ASC");
 
-    $descendants = $this->find_all($limit, $offset);
-    return $descendants;
+      $this->descendants[$type][$offset] = $this->find_all($limit, $offset);
+    }
+    return $this->descendants[$type][$offset];
   }
 
   /**
diff --git a/core/tests/ORM_MPTT_Test.php b/core/tests/ORM_MPTT_Test.php
index a053b61e..2b334243 100644
--- a/core/tests/ORM_MPTT_Test.php
+++ b/core/tests/ORM_MPTT_Test.php
@@ -95,6 +95,42 @@ class ORM_MPTT_Test extends Unit_Test_Case {
     $this->assert_equal(2, $outer->children_count());
   }
 
+  public function descendant_test() {
+    $parent = album::create(1, "parent album", "parent album title");
+    photo::create($parent->id, DOCROOT . "themes/default/images/thumbnail.jpg", "photo1", 
+                  "photo1", "parent album photo");
+
+    $album1 = album::create($parent->id, "album1", "album1 title");
+    photo::create($album1->id, DOCROOT . "themes/default/images/thumbnail.jpg", "photo1", 
+                  "photo1", "album1 photo");
+
+    $album2 = album::create($parent->id, "album2", "album2 title");
+    photo::create($album2->id, DOCROOT . "themes/default/images/thumbnail.jpg", "photo2", 
+                  "photo2", "album2 photo");
+    $parent->reload();
+
+    $this->assert_equal(5, $parent->descendants()->count());
+    $this->assert_equal(3, $parent->descendants(null, 0, "photo")->count());
+    $this->assert_equal(2, $parent->descendants(null, 0, "album")->count());
+  }
+
+  public function descendant_limit_test() {
+    $parent = album::create(1, "parent album", "parent album title");
+    photo::create($parent->id, DOCROOT . "themes/default/images/thumbnail.jpg", "photo1", 
+                  "photo1", "parent album photo");
+
+    $album1 = album::create($parent->id, "album1", "album1 title");
+    photo::create($album1->id, DOCROOT . "themes/default/images/thumbnail.jpg", "photo1", 
+                  "photo1", "album1 photo");
+
+    $album2 = album::create($parent->id, "album2", "album2 title");
+    photo::create($album2->id, DOCROOT . "themes/default/images/thumbnail.jpg", "photo2", 
+                  "photo2", "album2 photo");
+    $parent->reload();
+
+    $this->assert_equal(2, $parent->descendants(2)->count());
+  }
+
   public function descendant_count_test() {
     $parent = album::create(1, "parent album", "parent album title");
     photo::create($parent->id, DOCROOT . "themes/default/images/thumbnail.jpg", "photo1",