<?php

  namespace Sabre\DAV;

  /**
   * This interface represents a file in the directory tree
   *
   * A file is a bit of a broad definition. In general it implies that on
   * this specific node a PUT or GET method may be performed, to either update,
   * or retrieve the contents of the file.
   *

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

   */

  interface IFile extends INode {

  
      /**
       * Updates the data
       *
       * The data argument is a readable stream resource.
       *
       * After a succesful put operation, you may choose to return an ETag. The
       * etag must always be surrounded by double-quotes. These quotes must
       * appear in the actual string you're returning.
       *
       * Clients may use the ETag from a PUT request to later on make sure that
       * when they update the file, the contents haven't changed in the mean
       * time.
       *
       * If you don't plan to store the file byte-by-byte, and you return a
       * different object on a subsequent GET you are strongly recommended to not
       * return an ETag, and just return null.
       *
       * @param resource $data
       * @return string|null
       */
      function put($data);
  
      /**
       * Returns the data
       *
       * This method may either return a string or a readable stream resource
       *
       * @return mixed
       */
      function get();
  
      /**
       * Returns the mime-type for a file
       *
       * If null is returned, we'll assume application/octet-stream
       *
       * @return string|null
       */
      function getContentType();
  
      /**
       * Returns the ETag for a file
       *
       * An ETag is a unique identifier representing the current version of the file. If the file changes, the ETag MUST change.
       *
       * Return null if the ETag can not effectively be determined
       *
       * @return void
       */
      function getETag();
  
      /**
       * Returns the size of the node, in bytes
       *
       * @return int
       */
      function getSize();
  
  }