August 20, 2010 10:52 · Aug 20, 2010
diff --git a/gistfile1.php b/gistfile1.php
@@ -0,0 +1,187 @@
+<?php
+/**
+ *
+ * All nodes should be added from a list
+ * where the nodes are ordered by parent then id
+ *
+ * MikeC - My favourite object
+ */
+class Gravitywell_Tree
+{
+
+    /**
+     *  
+     * this node's id
+     */
+    public $id;
+
+    /**
+     * 
+     * parent id
+     */
+    public $parent;
+
+    /**
+     * 
+     * array of hops
+     */
+    public $hops;
+
+    /**
+     * 
+     * This object's data
+     */
+    public $data = null;
+
+    /**
+     * 
+     * Object Reference
+     */
+    protected $_arrRefs = array();
+
+    /**
+     * 
+     * Child nodes
+     */
+    protected $_childNodes = array();
+
+
+    /**
+     *
+     * Construct
+     */
+    public function __construct($id = 0, $parent = 0)
+    {
+        $this->id = $id;
+        $this->parent = $parent;
+        $this->_arrRefs[$id] = &$this;
+
+        // Add the root hop
+        $this->hops = array(0 => $id);
+    }
+
+
+    /**
+     * Add a child to a parent
+     *
+     */
+    public function addChild($parent, $id, $data = null)
+    {
+        if($obj = $this->findParent($parent)) {
+
+            // Rerun this class for the child
+            $newObj = new self($id, $parent);
+
+            // do hops
+            $newObj->hops          = $obj->hops;
+            $newObj->hops[]        = $id;
+
+            // add data
+            $newObj->data          = $data;
+
+            // Add our child node
+            $obj->_childNodes[$id] = $newObj;
+
+            // Create the reference to it
+            $this->_arrRefs[$id]   = &$newObj;  
+        }
+        else {
+            // Could not find the parent
+            throw new Exception('Gravitywell_Tree::addChild: Unknown parent id');
+        }
+    }
+
+    /**
+     * hasChildren
+     *
+     * does this obj node have children
+     */
+    public function hasChildren()
+    {
+        return (bool) count($this->_childNodes);
+    }
+
+    /**
+     * function getChildren
+     * @param $obj
+     * @return array of Gravitywell_Tree objects
+     */
+    public function getChildren($obj = null) {
+
+        if (!$obj) {
+            $obj = $this;
+        }
+
+        if (!$obj->hasChildren()) {
+            return false;
+        }
+
+        return $obj->_childNodes;
+    }
+
+    /**
+     *  return the array of hops from here to root node 
+     */
+    public function getHops()
+    {
+        return $this->hops;
+    }
+
+     /**
+     * findNode
+     *
+     * @param int $id
+     * @return object this|false
+     */
+    public function findNode($id)
+    {
+        return $this->findParent($id);
+    }
+
+     /**
+     * findChild
+     *
+     * @param int $id
+     * @return object this|false
+     **/
+    public function findChild($id)
+    {
+        return $this->findParent($id);
+    }
+
+
+    /**
+     * FindParent
+     *
+     * Finds the parent for a child/parent/node who cares?
+     *
+     * @param int $id
+     * @return object this|false
+     */
+    public function findParent($id)
+    {
+        if(isset ($this->_arrRefs[$id])) {
+            return $this->_arrRefs[$id];
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * 
+     * set this nodes data property
+     */
+    public function setData($data)
+    {
+        $this->data = $data;    
+    }
+
+    /**
+     * 
+     * returns the nodes data property
+     */
+    public function getData()
+    {
+        return $this->data;    
+    }
+}