examples-3.x-dev/modules/stream_wrapper_example/templates/description.html.twig

{#
/**
 * @file
 * Contains the description text of an Example explanation/description page
 *
 * Available variables:
 * - admin_link: The translated link pointing to a configuration page for the example.
 */
#}

<div class='examples-description'>

  {% trans %}
  <p>The Stream Wrapper Example module demonstrates a PHP stream wrapper implementation.
  A stream wrapper is a class that implements something that looks and behaves like a
  file system. A particular implementation of a stream wrapper is called a <em>scheme</em>.
  Drupal 8 supports public, private, and temporary wrapper schemes. For example, you
  access a file in your public uploads directory via a "public" file URI such as
  <code>public://images/big-logo.png</code>. When you read, write, delete or move that
  file, the <code>public</code> scheme's stream wrapper class
  (<code>\Drupal\Core\StreamWrapper\PublicStream</code>) is invoked to do the reading,
  writing, deletion or moving. PHP does this automatically for you, creating the wrapper
  whenever some file operation needs to get done on a <code>public://</code> file.
  </p>

  <p>To demonstrate how to implement a stream wrapper, this example module creates a
  <code>session</code> wrapper scheme. It uses your session data (created when you
  log into Drupal) to create a nested array where the arrays represent directories,
  and scalar values represent files.  This is completely impractical, and frankly,
  not terribly secure, so you should never enable this module on any site that's
  open to the Internet.  But without using any special libraries, our stream wrapper
  class is able to create and delete directories, and read and write files.
  </p>

  <p>If you want to play with <code>session</code> file URIs, we recommend also enabling
  the File Example (file_example.module), which will let you do the same things with
  the "session" scheme that you can do with public, private or temporary files.</p>

  <p>A longer description of what code is where can be found in
  <code>stream_wrapper_example.module</code>.  Definitely look through the code to see
  various implementation details.</p>
  {% endtrans %}

</div>