System Help block becomes Help block

The block that shows page-level help has changed.

Previously it was \Drupal\system\Plugin\Block\SystemHelpBlock, part of the System module, with ID "system_help_block" and displayed name "System Help".

Now it is \Drupal\help\Plugin\Block\HelpBlock, part of the Help module, with ID "help_block" and displayed name "Help".

If you have an automated test class that places this block, you'll need to make sure the 'help' module is enabled, and the block placement line will need to use the new ID. For example:

  // Previously, 'help' may not have been included:
  public static $modules = array('forum', 'node', 'block', 'menu_ui', 'help');
  // In setUp() -- this would have been 'system_help_block' previously:
    $this->drupalPlaceBlock('help_block', array('region' => 'help'));

If you have an install profile that places this block, the ID and provider of the block in the config/install will need to change. Example config/install file:

id: seven_help
theme: seven
weight: 0
status: true
langcode: en
region: help
plugin: help_block
settings:
  id: help_block
  label: 'Help'
  provider: help
  label_display: '0'
dependencies:
  module:
    - help
  theme:
    - seven
visibility: {  }

If you are doing something special in a theme, theme preprocessing, or block alter function for this block, you will also need to reference the new block ID. For instance, before:

function help_block_view_system_help_block_alter(array &$build, BlockPluginInterface $block) {
...
}
function help_preprocess_block(&$variables) {
  if ($variables['plugin_id'] == 'system_help_block') {
    $variables['attributes']['role'] = 'complementary';
  }
}

After:

function help_block_view_help_block_alter(array &$build, BlockPluginInterface $block) {
...
}
function help_preprocess_block(&$variables) {
  if ($variables['plugin_id'] == 'help_block') {
    $variables['attributes']['role'] = 'complementary';
  }
}