<?php

  namespace Sabre\DAV;

  /**
   * Collection class
   *
   * This is a helper class, that should aid in getting collections classes setup.
   * Most of its methods are implemented, and throw permission denied exceptions
   *

   * @copyright Copyright (C) 2007-2014 fruux GmbH (https://fruux.com/).
   * @author Evert Pot (http://evertpot.com/)
   * @license http://sabre.io/license/ Modified BSD License

   */

  abstract class Collection extends Node implements ICollection {

  
      /**
       * Returns a child object, by its name.
       *
       * This method makes use of the getChildren method to grab all the child
       * nodes, and compares the name.
       * Generally its wise to override this, as this can usually be optimized
       *

       * This method must throw Sabre\DAV\Exception\NotFound if the node does not

       * exist.
       *
       * @param string $name

       * @throws Exception\NotFound
       * @return INode

       */
      public function getChild($name) {
  
          foreach($this->getChildren() as $child) {
  
              if ($child->getName()==$name) return $child;
  
          }

          throw new Exception\NotFound('File not found: ' . $name);

  
      }
  
      /**
       * Checks is a child-node exists.
       *
       * It is generally a good idea to try and override this. Usually it can be optimized.
       *
       * @param string $name
       * @return bool
       */
      public function childExists($name) {
  
          try {
  
              $this->getChild($name);
              return true;

          } catch(Exception\NotFound $e) {

  
              return false;
  
          }
  
      }
  
      /**
       * Creates a new file in the directory
       *
       * Data will either be supplied as a stream resource, or in certain cases
       * as a string. Keep in mind that you may have to support either.
       *
       * After succesful creation of the file, you may choose to return the ETag
       * of the new file here.
       *
       * The returned ETag must be surrounded by double-quotes (The quotes should
       * be part of the actual string).
       *
       * If you cannot accurately determine the ETag, you should not return it.
       * If you don't store the file exactly as-is (you're transforming it
       * somehow) you should also not return an ETag.
       *
       * This means that if a subsequent GET to this new file does not exactly
       * return the same contents of what was submitted here, you are strongly
       * recommended to omit the ETag.
       *
       * @param string $name Name of the file
       * @param resource|string $data Initial payload
       * @return null|string
       */
      public function createFile($name, $data = null) {

          throw new Exception\Forbidden('Permission denied to create file (filename ' . $name . ')');

  
      }
  
      /**
       * Creates a new subdirectory
       *
       * @param string $name

       * @throws Exception\Forbidden

       * @return void
       */
      public function createDirectory($name) {

          throw new Exception\Forbidden('Permission denied to create directory');

  
      }
  
  
  }