NestedSet, Categorias anidadas...

NestedSet, Categorias anidadas...

Ponemos el Behaivor:
 
Category:
  actAs:
    Timestampable: ~
    NestedSet:
      hasManyRoots: true
      rootColumnName: root_id    
  columns:
    name: { type: string(100) }
 
Ponemos en el configure del form:
 
// create a new widget to represent this category's "parent"
  	$this->setWidget('parent', new sfWidgetFormDoctrineChoiceNestedSet(array(
	     	 'model'     => 'Category',
	      	 'add_empty' => true,
		)));

		// if the current category has a parent, make it the default choice
		if ($this->getObject()->getNode()->hasParent())
		{
			$this->setDefault('parent', $this->getObject()->getNode()->getParent()->getId());
		}

		// only allow the user to change the name of the category, and its parent
		$this->useFields(array(
	      	'name',
	      	'parent',
		));
		// set labels of fields
		$this->widgetSchema->setLabels(array(
	      	'name'   => 'Category',
	      	'parent' => 'Parent category',
		));
		// set a validator for parent which prevents a category being moved to one of its own descendants
		$this->setValidator('parent', new sfValidatorDoctrineChoiceNestedSet(array(
	    	 'required' => false,
	     	 'model'    => 'Category',
	     	 'node'     => $this->getObject(),
		)));
		$this->getValidator('parent')->setMessage('node', 'A category cannot be made a descendent of itself.');

if ($this->isNew()) {
			$this->getObject()->getNode()->insertAsLastChildOf($parent);
		}
		else
		{
			if($this->getObject()->getNode()->getParent()->getId() != $this->getValue(‘parent’)) // test to see if the parent has changed
			$this->getObject()->getNode()->moveAsLastChildOf($parent);
		}
 
 
Y por último en el evento doSave() del form:
 
/**
	 * Updates and saves the current object. Overrides the parent method
	 * by treating the record as a node in the nested set and updating
	 * the tree accordingly.
	 *
	 * @param Doctrine_Connection $con An optional connection parameter
	 */

	public function doSave($con = null)
	{
		// save the record itself
		parent::doSave($con);
		// if a parent has been specified, add/move this node to be the child of that node
		if ($this->getValue('parent'))
		{
			$parent = Doctrine::getTable('Category')->findOneById($this->getValue('parent'));
			if ($this->isNew())
			{
				$this->getObject()->getNode()->insertAsLastChildOf($parent);
			}
			else
			{
				$this->getObject()->getNode()->moveAsLastChildOf($parent);
			}
		}
		// if no parent was selected, add/move this node to be a new root in the tree
		else
		{
			$categoryTree = Doctrine::getTable('Category')->getTree();
			if ($this->isNew())
			{
				$categoryTree->createRoot($this->getObject());
			}
			else
			{
				$this->getObject()->getNode()->makeRoot($this->getObject()->getId());
			}
		}
	}
 
Creamos el un metodo en el table para ordenar el query por jerarquia.
 
public function retrieveSorted()
    {
    	return $this->createQuery()
    	->orderBy('root_id asc, lft asc')
    	->execute();
    }