Permissions: document and all childrens

<?php
	private function _duplicate($args)
	{
		// Load up the master doc (e.g. a folder) to be copied
	    $masterdoc = $modx->getObject('modResource', 123);
		
		// This will actually CREATE the doc. 
		$new_doc = $masterdoc->duplicate();
		
		if ( !is_object($new_doc) )
		{
			die('There was a problem duplicating the resource.');
		}
		
		$homepage_id = $new_doc->get('id');
		
		// Special handling for the homepage

		$new_doc->set('pagetitle', 'Some name' );
	    $new_doc->set('menutitle', 'Some menu title' );
	    $new_doc->set('alias', urlify('my-alias') );
	    $new_doc->set('published', 1); // 0 || 1

	    $new_doc->save();
	    
		// add resource group  (class var used in another function)
		$this->userResourceGroup = $modx->getObject('modResourceGroup', array('name'=> 'Name of my Resource Group') );	    
	    // add user group
	    $userUserGroup = $modx->getObject('modUserGroup', array('name'=> 'Name of my User Group' )
	
	    //add resource group access
	    $resourceGroupAccess = $modx->newObject('modAccessResourceGroup');
	    $resourceGroupAccess->set('target', $this->userResourceGroup->get('id'));
	    $resourceGroupAccess->set('principal_class', 'modUserGroup');
	    $resourceGroupAccess->set('principal', $userUserGroup->get('id'));
	    $resourceGroupAccess->set('authority', 9999); 
	    $resourceGroupAccess->set('policy', 4 ); // 4 for Load, List and View
	    $resourceGroupAccess->set('context_key', 'web');
	    $resourceGroupAccess->save();
	    

		// Process the children
		$this->_process_children_resources($new_doc);
	 	
	}
	
	/*------------------------------------------------------------------------------
	INPUT: MODx resource object, loops in on itself
	------------------------------------------------------------------------------*/
	private function _process_children_resources($resource)
	{
	    $children = $resource->getMany('Children');
		foreach ($children as $child) {
			
			$child->set('published', 1);	// Children docs published by default
			$child->save();
			
			$this->_join_resource_groups($child);
			// down the rabit hole
			$this->_process_children_resources($child);
		}	
	}

	/*------------------------------------------------------------------------------
	Removes a $doc from any resource groups it currently is in, then adds it to
	the whatever group was defined/created above via $this->userResourceGroup
	------------------------------------------------------------------------------*/
	private function _join_resource_groups($doc)
	{
		// Clear all existing access permissions
		$existing_resourceGroupResource = $modx->getCollection('modResourceGroupResource', array('document'=>$doc->get('id') ) );
		if ($existing_resourceGroupResource)
		{
			foreach ($existing_resourceGroupResource as $r)
			{
				$r->remove();
			}		
		}
		//add resource to resource group
		$resourceGroupResource = $modx->newObject('modResourceGroupResource');
		$resourceGroupResource->set('document', $doc->get('id'));
		$resourceGroupResource->set('document_group', $this->userResourceGroup->get('id'));
		$resourceGroupResource->save();
	}