<?php if (isset($block_html_id)): ?>
  <div id="<?php print $block_html_id; ?>" <?php print $attributes; ?>>
<?php else: ?>
  <div <?php print $attributes; ?>>
<?php endif; ?>
<?php print render($title_prefix); ?>
<?php if ($label): ?>
  <h2<?php print $title_attributes; ?>><?php print $label; ?></h2>
<?php endif;?>
  <?php print render($title_suffix); ?>
  <div<?php print $content_attributes; ?>>
    <?php print render($content) ?>
  </div>
</div>
   	  

<div{{ attributes }}>
  {{ title_prefix }}
  {% if label %}
    <h2{{ title_attributes }}>{{ label }}</h2>
  {% endif %}
  {{ title_suffix }}

  <div{{ content_attributes }}>
    {{ content }}
  </div>
</div>
   	  

abstract class ConfigurableActionBase extends ActionBase
        implements ConfigurablePluginInterface, PluginFormInterface {
//
interface ConfigurablePluginInterface {
  public function getConfiguration();
  public function setConfiguration(array $configuration);
  public function defaultConfiguration();
}
//
interface PluginFormInterface {
  public function buildConfigurationForm(array $form, array &$form_state);
  public function validateConfigurationForm(array &$form, array &$form_state);
  public function submitConfigurationForm(array &$form, array &$form_state);
}
      

  $action = entity_create('action', array(
    'id' => 'user_add_role_action.' . $role->id(),
    'type' => 'user',
    'label' => t('Add the @label role to the selected users',
    	array('@label' => $role->label())),
    'configuration' => array(
      'rid' => $role->id(),
    ),
    'plugin' => 'user_add_role_action',
  ));
  $action->save();
      

Drupal 7 has field_create_field(), field_create_instance(), update, delete and dozens of other field API crud functions and hooks.

$field = entity_create('field_entity', array(
  'entity_type' => 'node',
  'id' => 'field_image',
  'type' => 'image',
  'cardinality' => 1,
));
$field->save();
entity_create('field_instance', array(
  'field_id' => 'field_image',
  'entity_type' => 'node',
  'bundle' => 'article',
))->save();
    

$field = entity_load('field_image');
$field->cardinality = 3;
$field->settings['foo'] = 'bar';
$field->save();

$field->delete();

+
hook_entity_save()
hook_entity_delete()
...
      

$display = entity_get_display($entity_type, $bundle, $view_mode);
$display->setComponent('body', array(
  'type' => 'text_default',
  'weight' => 0,
))
-> save();
   

/**
 * @Widget(
 *   id = "mymodule_widget",
 *   label = @Translation("My awesome widget"),
 *   field_types = {
 *     "text"
 *   },
 *   settings = {
 *     "some_setting" = "Some default value"
 *   }
 * )
 */
class MyWidget extends WidgetBase {
	  

class MyWidget extends WidgetBase {

 public function settingsForm(array $form, array &$form_state);
 public function formElement(array $items, array &$form, array &$form_state);
 public function errorElement(array $element, array $error,
 								array $form, array &$form_state);
 public function massageFormValues(array $values, array $form, array &$form_state);

}
      

class MyFormatter extends FormatterBase {

  public function settingsForm(array $form, array &$form_state);
  public function settingsSummary();
  public function prepareView(array $entities, $langcode,array &$items);
  public function view(EntityInterface $entity, $langcode, array $items);

}
      

class TextItem extends TextItemBase {
(abstract class TextItemBase extends ConfigFieldItemBase)

 public static function schema(Field $field);
 public function settingsForm(array $form, array &$form_state);
 public function instanceSettingsForm(array $form, array &$form_state);

 public function validate() / presave() / delete() ...
      

Field values are objects

$node->field_tags instanceof FieldInterface
$node->field_tags[0] instanceof FieldItemInterface
      

Improved Developer experience

$node->body[LANGUAGE_NONE][0]['value']
         is now
$node->body->value
// or
$node->body[0]->value
      

$translation = $node->getTranslation('de');
// Access and update translated fields as usual:
$german_title = $translation->title->value;
$translation->title->value = 'Drupal spricht viele Sprachen!';

$node instanceof NodeInterface
$translation instanceof NodeInterface
      

$entity->getFieldDefinitions();

foreach ($entity as $field) {
  foreach ($field as $field_item) {
    $field_item->getPropertyDefinitions();
    foreach ($field_item as $item_value) {
      $is_string = $item_value instanceof StringInterface;
    }
  }
}
      

"Data type" plugins, include

• Primitives like: string, integer, date
• Field types
• Entity types

$properties['title'] = array(
  'label' => t('Title'),
  'description' => t('The title of this node, always treated as non-markup plain text.'),
  'type' => 'string_field',
);