diff --git a/core/modules/block_content/src/Tests/Views/BlockContentFieldFilterTest.php b/core/modules/block_content/src/Tests/Views/BlockContentFieldFilterTest.php
index 5ca1a5b59fb4b7e021cfdd25437d8436675cc6fb..c1cef647a9c76d2f663ab7514952348ec7056e2b 100644
--- a/core/modules/block_content/src/Tests/Views/BlockContentFieldFilterTest.php
+++ b/core/modules/block_content/src/Tests/Views/BlockContentFieldFilterTest.php
@@ -50,7 +50,7 @@ function setUp() {
     // Make the body field translatable. The info is already translatable by
     // definition.
     $field_storage = FieldStorageConfig::loadByName('block_content', 'body');
-    $field_storage->translatable = TRUE;
+    $field_storage->setTranslatable(TRUE);
     $field_storage->save();
 
     // Set up block_content infos.
diff --git a/core/modules/comment/src/Form/CommentTypeDeleteForm.php b/core/modules/comment/src/Form/CommentTypeDeleteForm.php
index 9a859e8d4cab33867b4437a64d8b07485944443a..deac0acfb7d8a293b85b663ad4c38a2190e929b4 100644
--- a/core/modules/comment/src/Form/CommentTypeDeleteForm.php
+++ b/core/modules/comment/src/Form/CommentTypeDeleteForm.php
@@ -97,7 +97,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
     $caption = '';
     foreach (array_keys($this->commentManager->getFields($entity_type)) as $field_name) {
       /** @var \Drupal\field\FieldStorageConfigInterface $field_storage */
-      if (($field_storage = FieldStorageConfig::loadByName($entity_type, $field_name)) && $field_storage->getSetting('comment_type') == $this->entity->id() && !$field_storage->deleted) {
+      if (($field_storage = FieldStorageConfig::loadByName($entity_type, $field_name)) && $field_storage->getSetting('comment_type') == $this->entity->id() && !$field_storage->isDeleted()) {
         $caption .= '<p>' . $this->t('%label is used by the %field field on your site. You can not remove this comment type until you have removed the field.', array(
           '%label' => $this->entity->label(),
           '%field' => $field_storage->label(),
diff --git a/core/modules/comment/src/Tests/CommentLanguageTest.php b/core/modules/comment/src/Tests/CommentLanguageTest.php
index 92f610e60fe73686f146e00598092a79a70bda1f..883eb1724377da74759ff3a4dd2929eec411a258 100644
--- a/core/modules/comment/src/Tests/CommentLanguageTest.php
+++ b/core/modules/comment/src/Tests/CommentLanguageTest.php
@@ -73,7 +73,7 @@ protected function setUp() {
 
     // Make comment body translatable.
     $field_storage = FieldStorageConfig::loadByName('comment', 'comment_body');
-    $field_storage->translatable = TRUE;
+    $field_storage->setTranslatable(TRUE);
     $field_storage->save();
     $this->assertTrue($field_storage->isTranslatable(), 'Comment body is translatable.');
   }
diff --git a/core/modules/config/src/Tests/ConfigExportImportUITest.php b/core/modules/config/src/Tests/ConfigExportImportUITest.php
index a1726496c193c6a08020520af2a1dfe190de0cba..f3aa1ff1ab680c05f1d359448fa41012b7fedbe6 100644
--- a/core/modules/config/src/Tests/ConfigExportImportUITest.php
+++ b/core/modules/config/src/Tests/ConfigExportImportUITest.php
@@ -143,7 +143,7 @@ public function testExportImport() {
     }
     $field_storages = FieldStorageConfig::loadMultiple();
     foreach ($field_storages as $field_storage) {
-      if ($field_storage->field_name == $this->fieldName) {
+      if ($field_storage->getName() == $this->fieldName) {
         $field_storage->delete();
       }
     }
diff --git a/core/modules/datetime/src/Tests/DateTimeFieldTest.php b/core/modules/datetime/src/Tests/DateTimeFieldTest.php
index 07707b98f39591043fcda4545ee575dc5d03f313..1f3a409d89d9300e0684259c48b2ce84049fafd7 100644
--- a/core/modules/datetime/src/Tests/DateTimeFieldTest.php
+++ b/core/modules/datetime/src/Tests/DateTimeFieldTest.php
@@ -95,7 +95,7 @@ protected function setUp() {
    * Tests date field functionality.
    */
   function testDateField() {
-    $field_name = $this->fieldStorage->field_name;
+    $field_name = $this->fieldStorage->getName();
 
     // Display creation form.
     $this->drupalGet('entity_test/add');
@@ -163,7 +163,7 @@ function testDateField() {
   function testDatetimeField() {
     $field_name = $this->fieldStorage->getName();
     // Change the field to a datetime field.
-    $this->fieldStorage->settings['datetime_type'] = 'datetime';
+    $this->fieldStorage->setSetting('datetime_type', 'datetime');
     $this->fieldStorage->save();
 
     // Display creation form.
@@ -229,7 +229,7 @@ function testDatetimeField() {
   function testDatelistWidget() {
     $field_name = $this->fieldStorage->getName();
     // Change the field to a datetime field.
-    $this->fieldStorage->settings['datetime_type'] = 'datetime';
+    $this->fieldStorage->setSetting('datetime_type', 'datetime');
     $this->fieldStorage->save();
 
     // Change the widget to a datelist widget.
@@ -393,7 +393,7 @@ function testDefaultValue() {
   function testInvalidField() {
 
     // Change the field to a datetime field.
-    $this->fieldStorage->settings['datetime_type'] = 'datetime';
+    $this->fieldStorage->setSetting('datetime_type', 'datetime');
     $this->fieldStorage->save();
     $field_name = $this->fieldStorage->getName();
 
diff --git a/core/modules/editor/src/Tests/QuickEditIntegrationTest.php b/core/modules/editor/src/Tests/QuickEditIntegrationTest.php
index 33077c3414e6fcf801d472dde646558ed165a65a..ab482374686684edd85b07c74b861b40a28957c1 100644
--- a/core/modules/editor/src/Tests/QuickEditIntegrationTest.php
+++ b/core/modules/editor/src/Tests/QuickEditIntegrationTest.php
@@ -145,7 +145,7 @@ public function testEditorSelection() {
     $this->assertEqual('editor', $this->getSelectedEditor($entity->id(), $this->fieldName), "With cardinality 1, and the full_html text format, the 'editor' editor is selected.");
 
     // Editor selection with text processing, cardinality >1
-    $this->fields->field_textarea_field_storage->cardinality = 2;
+    $this->fields->field_textarea_field_storage->setCardinality(2);
     $this->fields->field_textarea_field_storage->save();
     $this->assertEqual('form', $this->getSelectedEditor($entity->id(), $this->fieldName), "With cardinality >1, and both items using the full_html text format, the 'form' editor is selected.");
   }
diff --git a/core/modules/entity_reference/entity_reference.module b/core/modules/entity_reference/entity_reference.module
index b1b0619f685af5cfc99fb88d12a95926276e63a7..526c60cc6705d71b1ae064dc418623f6dfd1b218 100644
--- a/core/modules/entity_reference/entity_reference.module
+++ b/core/modules/entity_reference/entity_reference.module
@@ -69,7 +69,7 @@ function entity_reference_field_widget_info_alter(&$info) {
  * Reset the instance handler settings, when the target type is changed.
  */
 function entity_reference_field_storage_config_update(FieldStorageConfigInterface $field_storage) {
-  if ($field_storage->type != 'entity_reference') {
+  if ($field_storage->getType() != 'entity_reference') {
     // Only act on entity reference fields.
     return;
   }
diff --git a/core/modules/field/field.api.php b/core/modules/field/field.api.php
index bb39027a9fb5a1d731290ef8a25c035c99fcbe8e..55c239d7306caf218c641f631cfc918edbeb1a37 100644
--- a/core/modules/field/field.api.php
+++ b/core/modules/field/field.api.php
@@ -81,7 +81,7 @@ function hook_field_storage_config_update_forbid(\Drupal\field\FieldStorageConfi
     $allowed_values = $field_storage->getSetting('allowed_values');
     $prior_allowed_values = $prior_field_storage->getSetting('allowed_values');
     $lost_keys = array_keys(array_diff_key($prior_allowed_values,$allowed_values));
-    if (_options_values_in_use($field_storage->entity_type, $field_storage->getName(), $lost_keys)) {
+    if (_options_values_in_use($field_storage->getTargetEntityTypeId(), $field_storage->getName(), $lost_keys)) {
       throw new \Drupal\Core\Entity\Exception\FieldStorageDefinitionUpdateForbiddenException(t('A list field (@field_name) with existing data cannot have its keys changed.', array('@field_name' => $field_storage->getName())));
     }
   }
diff --git a/core/modules/field/field.module b/core/modules/field/field.module
index 5f95d50a9376b82fadfc7a0bd078692bc81d9491..3e9c9e0a35a6a518da5b4d8e2ddda2becaf088d5 100644
--- a/core/modules/field/field.module
+++ b/core/modules/field/field.module
@@ -153,7 +153,7 @@ function field_system_info_alter(&$info, Extension $file, $type) {
       // remains no actual, non-deleted fields)
       $non_deleted = FALSE;
       foreach ($field_storages as $field_storage) {
-        if (empty($field_storage->deleted)) {
+        if (!$field_storage->isDeleted()) {
           $non_deleted = TRUE;
           break;
         }
diff --git a/core/modules/field/field.purge.inc b/core/modules/field/field.purge.inc
index 73de63f200655e5416813468d6fc609f3a2b46ee..4af0f4e4ec452cb5aa2ebc3dd6c669689964ffab 100644
--- a/core/modules/field/field.purge.inc
+++ b/core/modules/field/field.purge.inc
@@ -84,7 +84,7 @@ function field_purge_batch($batch_size, $field_storage_uuid = NULL) {
 
   $info = \Drupal::entityManager()->getDefinitions();
   foreach ($fields as $field) {
-    $entity_type = $field->entity_type;
+    $entity_type = $field->getTargetEntityTypeId();
 
     // We cannot purge anything if the entity type is unknown (e.g. the
     // providing module was uninstalled).
@@ -117,7 +117,7 @@ function field_purge_batch($batch_size, $field_storage_uuid = NULL) {
     // We cannot purge anything if the entity type is unknown (e.g. the
     // providing module was uninstalled).
     // @todo Revisit after https://drupal.org/node/2080823.
-    if (!isset($info[$field_storage->entity_type])) {
+    if (!isset($info[$field_storage->getTargetEntityTypeId()])) {
       continue;
     }
 
@@ -170,7 +170,7 @@ function field_purge_field_storage(FieldStorageConfigInterface $field_storage) {
   $state->set('field.storage.deleted', $deleted_storages);
 
   // Notify the storage layer.
-  \Drupal::entityManager()->getStorage($field_storage->entity_type)->finalizePurge($field_storage);
+  \Drupal::entityManager()->getStorage($field_storage->getTargetEntityTypeId())->finalizePurge($field_storage);
 
   // Invoke external hooks after the cache is cleared for API consistency.
   \Drupal::moduleHandler()->invokeAll('field_purge_field_storage', array($field_storage));
diff --git a/core/modules/field/src/ConfigImporterFieldPurger.php b/core/modules/field/src/ConfigImporterFieldPurger.php
index 55294b21a076633b63af20af337f9ff9a3218206..efc39a23f4a83123701f169d98d6a88ea737dcbd 100644
--- a/core/modules/field/src/ConfigImporterFieldPurger.php
+++ b/core/modules/field/src/ConfigImporterFieldPurger.php
@@ -40,7 +40,7 @@ public static function process(array &$context, ConfigImporter $config_importer)
       $context['sandbox']['field']['current_storage_id'] = $field_storage->id();
       // If the storage has not been deleted yet we need to do that. This is the
       // case when the storage deletion is staged.
-      if (!$field_storage->deleted) {
+      if (!$field_storage->isDeleted()) {
         $field_storage->delete();
       }
     }
@@ -138,9 +138,10 @@ public static function getFieldStoragesToPurge(array $extensions, array $deletes
     }
 
     // Gather deleted fields from modules that are being uninstalled.
+    /** @var \Drupal\field\FieldStorageConfigInterface[] $field_storages */
     $field_storages = entity_load_multiple_by_properties('field_storage_config', array('deleted' => TRUE, 'include_deleted' => TRUE));
     foreach ($field_storages as $field_storage) {
-      if (!in_array($field_storage->module, $providers)) {
+      if (!in_array($field_storage->getTypeProvider(), $providers)) {
         $storages_to_delete[$field_storage->id()] = $field_storage;
       }
     }
diff --git a/core/modules/field/src/Entity/FieldConfig.php b/core/modules/field/src/Entity/FieldConfig.php
index dc5607a330bd8cea2e0d405d8ea76d0020fb48a4..c5b9ad5aa479540d9c6cba3d03218710effb1674 100644
--- a/core/modules/field/src/Entity/FieldConfig.php
+++ b/core/modules/field/src/Entity/FieldConfig.php
@@ -141,7 +141,7 @@ public function preSave(EntityStorageInterface $storage) {
     // Filter out unknown settings and make sure all settings are present, so
     // that a complete field definition is passed to the various hooks and
     // written to config.
-    $default_settings = $field_type_manager->getDefaultFieldSettings($storage_definition->type);
+    $default_settings = $field_type_manager->getDefaultFieldSettings($storage_definition->getType());
     $this->settings = array_intersect_key($this->settings, $default_settings) + $default_settings;
 
     if ($this->isNew()) {
diff --git a/core/modules/field/src/Entity/FieldStorageConfig.php b/core/modules/field/src/Entity/FieldStorageConfig.php
index a64f7136099e5a0e1b81f5bcd32dab5b7b29a620..ab869db20ed99d7fbca6eec24c09b67700067100 100644
--- a/core/modules/field/src/Entity/FieldStorageConfig.php
+++ b/core/modules/field/src/Entity/FieldStorageConfig.php
@@ -51,7 +51,7 @@ class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigI
    *
    * @var string
    */
-  public $id;
+  protected $id;
 
   /**
    * The field name.
@@ -64,14 +64,14 @@ class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigI
    *
    * @var string
    */
-  public $field_name;
+  protected $field_name;
 
   /**
    * The name of the entity type the field can be attached to.
    *
    * @var string
    */
-  public $entity_type;
+  protected $entity_type;
 
   /**
    * The field type.
@@ -80,14 +80,14 @@ class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigI
    *
    * @var string
    */
-  public $type;
+  protected $type;
 
   /**
    * The name of the module that provides the field type.
    *
    * @var string
    */
-  public $module;
+  protected $module;
 
   /**
    * Field-type specific settings.
@@ -97,7 +97,7 @@ class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigI
    *
    * @var array
    */
-  public $settings = array();
+  protected $settings = [];
 
   /**
    * The field cardinality.
@@ -108,7 +108,7 @@ class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigI
    *
    * @var int
    */
-  public $cardinality = 1;
+  protected $cardinality = 1;
 
   /**
    * Flag indicating whether the field is translatable.
@@ -117,7 +117,7 @@ class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigI
    *
    * @var bool
    */
-  public $translatable = TRUE;
+  protected $translatable = TRUE;
 
   /**
    * Flag indicating whether the field is available for editing.
@@ -131,7 +131,7 @@ class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigI
    *
    * @var bool
    */
-  public $locked = FALSE;
+  protected $locked = FALSE;
 
   /**
    * Flag indicating whether the field storage should be deleted when orphaned.
@@ -164,7 +164,7 @@ class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigI
    *
    * @var array
    */
-  public $indexes = array();
+  protected $indexes = [];
 
   /**
    * Flag indicating whether the field is deleted.
@@ -179,7 +179,7 @@ class FieldStorageConfig extends ConfigEntityBase implements FieldStorageConfigI
    *
    * @var bool
    */
-  public $deleted = FALSE;
+  protected $deleted = FALSE;
 
   /**
    * The field schema.
@@ -238,7 +238,7 @@ public function __construct(array $values, $entity_type = 'field_storage_config'
    * {@inheritdoc}
    */
   public function id() {
-    return $this->entity_type . '.' . $this->field_name;
+    return $this->getTargetEntityTypeId() . '.' . $this->getName();
   }
 
   /**
@@ -288,25 +288,25 @@ protected function preSaveNew(EntityStorageInterface $storage) {
     // Field name cannot be longer than FieldStorageConfig::NAME_MAX_LENGTH characters.
     // We use Unicode::strlen() because the DB layer assumes that column widths
     // are given in characters rather than bytes.
-    if (Unicode::strlen($this->field_name) > static::NAME_MAX_LENGTH) {
+    if (Unicode::strlen($this->getName()) > static::NAME_MAX_LENGTH) {
       throw new FieldException(String::format(
         'Attempt to create a field storage with an name longer than @max characters: %name', array(
           '@max' => static::NAME_MAX_LENGTH,
-          '%name' => $this->field_name,
+          '%name' => $this->getName(),
         )
       ));
     }
 
     // Disallow reserved field names.
-    $disallowed_field_names = array_keys($entity_manager->getBaseFieldDefinitions($this->entity_type));
-    if (in_array($this->field_name, $disallowed_field_names)) {
-      throw new FieldException(String::format('Attempt to create field storage %name which is reserved by entity type %type.', array('%name' => $this->field_name, '%type' => $this->entity_type)));
+    $disallowed_field_names = array_keys($entity_manager->getBaseFieldDefinitions($this->getTargetEntityTypeId()));
+    if (in_array($this->getName(), $disallowed_field_names)) {
+      throw new FieldException(String::format('Attempt to create field storage %name which is reserved by entity type %type.', array('%name' => $this->getName(), '%type' => $this->getTargetEntityTypeId())));
     }
 
     // Check that the field type is known.
-    $field_type = $field_type_manager->getDefinition($this->type, FALSE);
+    $field_type = $field_type_manager->getDefinition($this->getType(), FALSE);
     if (!$field_type) {
-      throw new FieldException(String::format('Attempt to create a field storage of unknown type %type.', array('%type' => $this->type)));
+      throw new FieldException(String::format('Attempt to create a field storage of unknown type %type.', array('%type' => $this->getType())));
     }
     $this->module = $field_type['provider'];
 
@@ -320,7 +320,7 @@ protected function preSaveNew(EntityStorageInterface $storage) {
   public function calculateDependencies() {
     parent::calculateDependencies();
     // Ensure the field is dependent on the providing module.
-    $this->addDependency('module', $this->module);
+    $this->addDependency('module', $this->getTypeProvider());
     // Ensure the field is dependent on the provider of the entity type.
     $entity_type = \Drupal::entityManager()->getDefinition($this->entity_type);
     $this->addDependency('module', $entity_type->getProvider());
@@ -338,10 +338,10 @@ protected function preSaveUpdated(EntityStorageInterface $storage) {
     $entity_manager = \Drupal::entityManager();
 
     // Some updates are always disallowed.
-    if ($this->type != $this->original->type) {
+    if ($this->getType() != $this->original->getType()) {
       throw new FieldException("Cannot change the field type for an existing field storage.");
     }
-    if ($this->entity_type != $this->original->entity_type) {
+    if ($this->getTargetEntityTypeId() != $this->original->getTargetEntityTypeId()) {
       throw new FieldException("Cannot change the entity type for an existing field storage.");
     }
 
@@ -383,7 +383,9 @@ public static function preDelete(EntityStorageInterface $storage, array $field_s
     foreach ($field_storages as $field_storage) {
       if (!$field_storage->deleted) {
         foreach ($field_storage->getBundles() as $bundle) {
-          $field_ids[] = "{$field_storage->entity_type}.$bundle.{$field_storage->field_name}";
+          $entity_type = $field_storage->getTargetEntityTypeId();
+          $field_name = $field_storage->getName();
+          $field_ids[] = "{$entity_type}.$bundle.{$field_name}";
         }
       }
     }
@@ -481,10 +483,10 @@ public function getColumns() {
    * {@inheritdoc}
    */
   public function getBundles() {
-    if (empty($this->deleted)) {
+    if (!$this->isDeleted()) {
       $map = \Drupal::entityManager()->getFieldMap();
-      if (isset($map[$this->entity_type][$this->field_name]['bundles'])) {
-        return $map[$this->entity_type][$this->field_name]['bundles'];
+      if (isset($map[$this->getTargetEntityTypeId()][$this->getName()]['bundles'])) {
+        return $map[$this->getTargetEntityTypeId()][$this->getName()]['bundles'];
       }
     }
     return array();
@@ -497,6 +499,20 @@ public function getName() {
     return $this->field_name;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function isDeleted() {
+    return $this->deleted;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getTypeProvider() {
+    return $this->module;
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -514,7 +530,7 @@ public function getSettings() {
     //   within $this.
     $field_type_manager = \Drupal::service('plugin.manager.field.field_type');
 
-    $settings = $field_type_manager->getDefaultStorageSettings($this->type);
+    $settings = $field_type_manager->getDefaultStorageSettings($this->getType());
     return $this->settings + $settings;
   }
 
@@ -537,6 +553,22 @@ public function getSetting($setting_name) {
     }
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function setSetting($setting_name, $value) {
+    $this->settings[$setting_name] = $value;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setSettings(array $settings) {
+    $this->settings = $settings;
+    return $this;
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -588,6 +620,14 @@ public function getCardinality() {
     return $this->cardinality;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function setCardinality($cardinality) {
+    $this->cardinality = $cardinality;
+    return $this;
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -618,6 +658,14 @@ public function isLocked() {
     return $this->locked;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function setLocked($locked) {
+    $this->locked = $locked;
+    return $this;
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -750,4 +798,19 @@ public function isDeletable() {
     return !$this->deleted && !$this->persist_with_no_fields && count($this->getBundles()) == 0;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getIndexes() {
+    return $this->indexes;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setIndexes(array $indexes) {
+    $this->indexes = $indexes;
+    return $this;
+  }
+
 }
diff --git a/core/modules/field/src/FieldStorageConfigInterface.php b/core/modules/field/src/FieldStorageConfigInterface.php
index de0406b5bea302e301b9a0f69e5eac94d868837f..116517aed3291aff1df9e5a8aad6f60ba700323f 100644
--- a/core/modules/field/src/FieldStorageConfigInterface.php
+++ b/core/modules/field/src/FieldStorageConfigInterface.php
@@ -15,6 +15,22 @@
  */
 interface FieldStorageConfigInterface extends ConfigEntityInterface, FieldStorageDefinitionInterface {
 
+  /**
+   * Returns the field type.
+   *
+   * @return string
+   *   The field type, i.e. the id of a field type plugin. For example 'text'.
+   */
+  public function getType();
+
+  /**
+   * Returns the name of the module providing the field type.
+   *
+   * @return string
+   *   The name of the module that provides the field type.
+   */
+  public function getTypeProvider();
+
   /**
    * Returns the list of bundles where the field storage has fields.
    *
@@ -24,12 +40,12 @@ interface FieldStorageConfigInterface extends ConfigEntityInterface, FieldStorag
   public function getBundles();
 
   /**
-   * Returns whether the field storage is locked or not.
+   * Returns whether the field is deleted or not.
    *
    * @return bool
-   *   TRUE if the field storage is locked.
+   *   TRUE if the field is deleted.
    */
-  public function isLocked();
+  public function isDeleted();
 
   /**
    * Checks if the field storage can be deleted.
@@ -39,4 +55,82 @@ public function isLocked();
    */
   public function isDeletable();
 
+  /**
+   * Returns whether the field storage is locked or not.
+   *
+   * @return bool
+   *   TRUE if the field storage is locked.
+   */
+  public function isLocked();
+
+  /**
+   * Sets the locked flag.
+   *
+   * @param bool $locked
+   *   Sets value of locked flag.
+   *
+   * @return $this
+   */
+  public function setLocked($locked);
+
+  /**
+   * Sets the maximum number of items allowed for the field.
+   *
+   * @param int $cardinality
+   *   The cardinality value.
+   *
+   * @return $this
+   */
+  public function setCardinality($cardinality);
+
+  /**
+   * Sets the value for a field setting by name.
+   *
+   * @param string $setting_name
+   *   The name of the setting.
+   * @param mixed $value
+   *   The value of the setting.
+   *
+   * @return $this
+   */
+  public function setSetting($setting_name, $value);
+
+  /**
+   * Sets field settings (overwrites existing settings).
+   *
+   * @param array $settings
+   *   The array of field settings.
+   *
+   * @return $this
+   */
+  public function setSettings(array $settings);
+
+  /**
+   * Sets whether the field is translatable.
+   *
+   * @param bool $translatable
+   *   Whether the field is translatable.
+   *
+   * @return $this
+   */
+  public function setTranslatable($translatable);
+
+  /**
+   * Returns the custom storage indexes for the field data storage.
+   *
+   * @return array
+   *   An array of custom indexes.
+   */
+  public function getIndexes();
+
+  /**
+   * Sets the custom storage indexes for the field data storage..
+   *
+   * @param array $indexes
+   *   The array of custom indexes.
+   *
+   * @return $this
+   */
+  public function setIndexes(array $indexes);
+
 }
diff --git a/core/modules/field/src/FieldStorageConfigStorage.php b/core/modules/field/src/FieldStorageConfigStorage.php
index d865d851f3521fce858f56c15d674ce9cfd2e631..55800b36e6c1b837e020fd6ef04e2f7cbd8c95c8 100644
--- a/core/modules/field/src/FieldStorageConfigStorage.php
+++ b/core/modules/field/src/FieldStorageConfigStorage.php
@@ -104,6 +104,7 @@ public function loadByProperties(array $conditions = array()) {
     $include_deleted = isset($conditions['include_deleted']) ? $conditions['include_deleted'] : FALSE;
     unset($conditions['include_deleted']);
 
+    /** @var \Drupal\field\FieldStorageConfigInterface[] $storages */
     $storages = array();
 
     // Get field storages living in configuration. If we are explicitly looking
@@ -134,16 +135,7 @@ public function loadByProperties(array $conditions = array()) {
     foreach ($storages as $field) {
       foreach ($conditions as $key => $value) {
         // Extract the actual value against which the condition is checked.
-        switch ($key) {
-          case 'uuid';
-            $checked_value = $field->uuid();
-            break;
-
-          default:
-            $checked_value = $field->$key;
-            break;
-        }
-
+        $checked_value = $field->get($key);
         // Skip to the next field as soon as one condition does not match.
         if ($checked_value != $value) {
           continue 2;
diff --git a/core/modules/field/src/Tests/BulkDeleteTest.php b/core/modules/field/src/Tests/BulkDeleteTest.php
index 4ae227b916b618d68c362a7fa96f2e266be75f5a..be306e5ace16dc449a2f14a91714f43cb422e3ed 100644
--- a/core/modules/field/src/Tests/BulkDeleteTest.php
+++ b/core/modules/field/src/Tests/BulkDeleteTest.php
@@ -314,7 +314,7 @@ function testPurgeFieldStorage() {
     $this->assertEqual(count($fields), 0, 'The field is purged.');
     // The field storage still exists, not deleted.
     $storages = entity_load_multiple_by_properties('field_storage_config', array('uuid' => $field_storage->uuid(), 'include_deleted' => TRUE));
-    $this->assertTrue(isset($storages[$field_storage->uuid()]) && !$storages[$field_storage->uuid()]->deleted, 'The field storage exists and is not deleted');
+    $this->assertTrue(isset($storages[$field_storage->uuid()]) && !$storages[$field_storage->uuid()]->isDeleted(), 'The field storage exists and is not deleted');
 
     // Delete the second field.
     $bundle = next($this->bundles);
@@ -341,7 +341,7 @@ function testPurgeFieldStorage() {
     $fields = entity_load_multiple_by_properties('field_config', array('uuid' => $field->uuid(), 'include_deleted' => TRUE));
     $this->assertTrue(isset($fields[$field->uuid()]) && $fields[$field->uuid()]->deleted, 'The field exists and is deleted');
     $storages = entity_load_multiple_by_properties('field_storage_config', array('uuid' => $field_storage->uuid(), 'include_deleted' => TRUE));
-    $this->assertTrue(isset($storages[$field_storage->uuid()]) && $storages[$field_storage->uuid()]->deleted, 'The field storage exists and is deleted');
+    $this->assertTrue(isset($storages[$field_storage->uuid()]) && $storages[$field_storage->uuid()]->isDeleted(), 'The field storage exists and is deleted');
 
     // Purge again to purge the field and the storage.
     field_purge_batch(0);
diff --git a/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php b/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
index 6cc771899179428f961b448926477cd8b052ff67..d940188d2d858da4cda5158503f6448aef3100b9 100644
--- a/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
+++ b/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
@@ -244,7 +244,7 @@ public function testLabelFormatter() {
     // \Drupal\Core\Entity\EntityInterface::urlInfo() will throw an exception
     // and the label formatter will output only the label instead of a link.
     $field_storage_config = FieldStorageConfig::loadByName($this->entityType, $this->fieldName);
-    $field_storage_config->settings['target_type'] = 'entity_test_label';
+    $field_storage_config->setSetting('target_type', 'entity_test_label');
     $field_storage_config->save();
 
     $referenced_entity_with_no_link_template = entity_create('entity_test_label', array(
diff --git a/core/modules/field/src/Tests/FieldCrudTest.php b/core/modules/field/src/Tests/FieldCrudTest.php
index 94639e1de6b38cfcc0130095f7cf9f018691137c..33ace63b7371d95759f33b1cb4ed33ad8d30afe4 100644
--- a/core/modules/field/src/Tests/FieldCrudTest.php
+++ b/core/modules/field/src/Tests/FieldCrudTest.php
@@ -207,10 +207,10 @@ function testDeleteFieldCrossDeletion() {
     entity_create('field_config', $this->fieldDefinition)->save();
     entity_create('field_config', $field_definition_2)->save();
     $field_storage->delete();
-    $this->assertFalse(FieldConfig::loadByName('entity_test', $this->fieldDefinition['bundle'], $field_storage->field_name));
-    $this->assertFalse(FieldConfig::loadByName('entity_test', $field_definition_2['bundle'], $field_storage->field_name));
+    $this->assertFalse(FieldConfig::loadByName('entity_test', $this->fieldDefinition['bundle'], $field_storage->getName()));
+    $this->assertFalse(FieldConfig::loadByName('entity_test', $field_definition_2['bundle'], $field_storage->getName()));
 
-    // Chack that deletion of the last field deletes the storage.
+    // Check that deletion of the last field deletes the storage.
     $field_storage = entity_create('field_storage_config', $this->fieldStorageDefinition);
     $field_storage->save();
     $field = entity_create('field_config', $this->fieldDefinition);
@@ -218,9 +218,9 @@ function testDeleteFieldCrossDeletion() {
     $field_2 = entity_create('field_config', $field_definition_2);
     $field_2->save();
     $field->delete();
-    $this->assertTrue(FieldStorageConfig::loadByName('entity_test', $field_storage->field_name));
+    $this->assertTrue(FieldStorageConfig::loadByName('entity_test', $field_storage->getName()));
     $field_2->delete();
-    $this->assertFalse(FieldStorageConfig::loadByName('entity_test', $field_storage->field_name));
+    $this->assertFalse(FieldStorageConfig::loadByName('entity_test', $field_storage->getName()));
 
     // Check that deletion of all fields using a storage simultaneously deletes
     // the storage.
@@ -231,7 +231,7 @@ function testDeleteFieldCrossDeletion() {
     $field_2 = entity_create('field_config', $field_definition_2);
     $field_2->save();
     $this->container->get('entity.manager')->getStorage('field_config')->delete(array($field, $field_2));
-    $this->assertFalse(FieldStorageConfig::loadByName('entity_test', $field_storage->field_name));
+    $this->assertFalse(FieldStorageConfig::loadByName('entity_test', $field_storage->getName()));
   }
 
   /**
diff --git a/core/modules/field/src/Tests/FieldStorageCrudTest.php b/core/modules/field/src/Tests/FieldStorageCrudTest.php
index 365f1367fe65895f1acee2f504d2e90cd27f12e1..37e4afbe75af1a6e75916b21a842fe6eda8f20d7 100644
--- a/core/modules/field/src/Tests/FieldStorageCrudTest.php
+++ b/core/modules/field/src/Tests/FieldStorageCrudTest.php
@@ -305,13 +305,13 @@ function testDelete() {
 
     // Test that the first field is not deleted, and then delete it.
     $field_storage = current(entity_load_multiple_by_properties('field_storage_config', array('field_name' => $field_storage_definition['field_name'], 'include_deleted' => TRUE)));
-    $this->assertTrue(!empty($field_storage) && empty($field_storage->deleted), 'A new storage is not marked for deletion.');
+    $this->assertTrue(!empty($field_storage) && !$field_storage->isDeleted(), 'A new storage is not marked for deletion.');
     FieldStorageConfig::loadByName('entity_test', $field_storage_definition['field_name'])->delete();
 
     // Make sure that the field is marked as deleted when it is specifically
     // loaded.
     $field_storage = current(entity_load_multiple_by_properties('field_storage_config', array('field_name' => $field_storage_definition['field_name'], 'include_deleted' => TRUE)));
-    $this->assertTrue(!empty($field_storage->deleted), 'A deleted storage is marked for deletion.');
+    $this->assertTrue($field_storage->isDeleted(), 'A deleted storage is marked for deletion.');
 
     // Make sure that this field is marked as deleted when it is
     // specifically loaded.
@@ -328,7 +328,7 @@ function testDelete() {
 
     // Make sure the other field and its storage are not deleted.
     $another_field_storage = FieldStorageConfig::load('entity_test.' . $another_field_storage_definition['field_name']);
-    $this->assertTrue(!empty($another_field_storage) && empty($another_field_storage->deleted), 'A non-deleted storage is not marked for deletion.');
+    $this->assertTrue(!empty($another_field_storage) && !$another_field_storage->isDeleted(), 'A non-deleted storage is not marked for deletion.');
     $another_field = FieldConfig::load('entity_test.' . $another_field_definition['bundle'] . '.' . $another_field_definition['field_name']);
     $this->assertTrue(!empty($another_field) && empty($another_field->deleted), 'A field whose storage was not deleted is not marked for deletion.');
 
@@ -337,7 +337,7 @@ function testDelete() {
     entity_create('field_storage_config', $field_storage_definition)->save();
     entity_create('field_config', $field_definition)->save();
     $field_storage = FieldStorageConfig::load('entity_test.' . $field_storage_definition['field_name']);
-    $this->assertTrue(!empty($field_storage) && empty($field_storage->deleted), 'A new storage with a previously used name is created.');
+    $this->assertTrue(!empty($field_storage) && !$field_storage->isDeleted(), 'A new storage with a previously used name is created.');
     $field = FieldConfig::load('entity_test.' . $field_definition['bundle'] . '.' . $field_definition['field_name'] );
     $this->assertTrue(!empty($field) && empty($field->deleted), 'A new field for a previously used field name is created.');
 
@@ -363,7 +363,7 @@ function testUpdateFieldType() {
     $field_storage->save();
 
     try {
-      $field_storage->type = 'integer';
+      $field_storage->set('type', 'integer');
       $field_storage->save();
       $this->fail(t('Cannot update a field to a different type.'));
     }
@@ -403,13 +403,13 @@ function testUpdate() {
       }
       // Load back and assert there are $cardinality number of values.
       $entity = $this->entitySaveReload($entity);
-      $this->assertEqual(count($entity->field_update), $field_storage->cardinality);
+      $this->assertEqual(count($entity->field_update), $field_storage->getCardinality());
       // Now check the values themselves.
       for ($delta = 0; $delta < $cardinality; $delta++) {
         $this->assertEqual($entity->field_update[$delta]->value, $delta + 1);
       }
       // Increase $cardinality and set the field cardinality to the new value.
-      $field_storage->cardinality = ++$cardinality;
+      $field_storage->setCardinality(++$cardinality);
       $field_storage->save();
     } while ($cardinality < 6);
   }
@@ -427,7 +427,7 @@ function testUpdateForbid() {
         'unchangeable' => 0
     )));
     $field_storage->save();
-    $field_storage->settings['changeable']++;
+    $field_storage->setSetting('changeable', $field_storage->getSetting('changeable') + 1);
     try {
       $field_storage->save();
       $this->pass(t("A changeable setting can be updated."));
@@ -435,7 +435,7 @@ function testUpdateForbid() {
     catch (FieldStorageDefinitionUpdateForbiddenException $e) {
       $this->fail(t("An unchangeable setting cannot be updated."));
     }
-    $field_storage->settings['unchangeable']++;
+    $field_storage->setSetting('unchangeable', $field_storage->getSetting('unchangeable') + 1);
     try {
       $field_storage->save();
       $this->fail(t("An unchangeable setting can be updated."));
diff --git a/core/modules/field/src/Tests/FieldValidationTest.php b/core/modules/field/src/Tests/FieldValidationTest.php
index 71bb8adbb46e2c6809e1fd0e268fb0a88fe3bcf6..8f51b7aa500db0086074aeaf9f4c4674ad908634 100644
--- a/core/modules/field/src/Tests/FieldValidationTest.php
+++ b/core/modules/field/src/Tests/FieldValidationTest.php
@@ -48,7 +48,7 @@ protected function setUp() {
    * Tests that the number of values is validated against the field cardinality.
    */
   function testCardinalityConstraint() {
-    $cardinality = $this->fieldTestData->field_storage->cardinality;
+    $cardinality = $this->fieldTestData->field_storage->getCardinality();
     $entity = $this->entity;
 
     for ($delta = 0; $delta < $cardinality + 1; $delta++) {
diff --git a/core/modules/field/src/Tests/reEnableModuleFieldTest.php b/core/modules/field/src/Tests/reEnableModuleFieldTest.php
index 2b8f4c14d3414fbf04a812220460b9da7fa15ee6..52ce2a36ce31e82acb5bbcaa16673242402f17e3 100644
--- a/core/modules/field/src/Tests/reEnableModuleFieldTest.php
+++ b/core/modules/field/src/Tests/reEnableModuleFieldTest.php
@@ -39,6 +39,8 @@ protected function setUp() {
 
   /**
    * Test the behavior of a field module after being disabled and re-enabled.
+   *
+   * @see field_system_info_alter()
    */
   function testReEnabledField() {
 
diff --git a/core/modules/field_ui/src/FieldConfigListBuilder.php b/core/modules/field_ui/src/FieldConfigListBuilder.php
index 167d9f7269d195372fa4d5e377c3a6fa343c8f6c..e44bc69395ffbed7106b0a95fc7de534ea9e988a 100644
--- a/core/modules/field_ui/src/FieldConfigListBuilder.php
+++ b/core/modules/field_ui/src/FieldConfigListBuilder.php
@@ -149,7 +149,7 @@ public function buildRow(EntityInterface $field_config) {
     // Add the operations.
     $row['data'] = $row['data'] + parent::buildRow($field_config);
 
-    if (!empty($field_storage->locked)) {
+    if ($field_storage->isLocked()) {
       $row['data']['operations'] = array('data' => array('#markup' => $this->t('Locked')));
       $row['class'][] = 'menu-disabled';
     }
diff --git a/core/modules/field_ui/src/FieldStorageConfigListBuilder.php b/core/modules/field_ui/src/FieldStorageConfigListBuilder.php
index a5120464b61653077f6396a9f434a39818c69871..d0fe42f7195e0bd319a9cb14af3c705a480d4166 100644
--- a/core/modules/field_ui/src/FieldStorageConfigListBuilder.php
+++ b/core/modules/field_ui/src/FieldStorageConfigListBuilder.php
@@ -98,24 +98,25 @@ public function buildHeader() {
    * {@inheritdoc}
    */
   public function buildRow(EntityInterface $field_storage) {
-    if ($field_storage->locked) {
+    if ($field_storage->isLocked()) {
       $row['class'] = array('menu-disabled');
-      $row['data']['id'] =  t('@field_name (Locked)', array('@field_name' => $field_storage->field_name));
+      $row['data']['id'] =  t('@field_name (Locked)', array('@field_name' => $field_storage->getName()));
     }
     else {
-      $row['data']['id'] = $field_storage->field_name;
+      $row['data']['id'] = $field_storage->getName();
     }
 
-    $field_type = $this->fieldTypes[$field_storage->type];
+    $field_type = $this->fieldTypes[$field_storage->getType()];
     $row['data']['type'] = t('@type (module: @module)', array('@type' => $field_type['label'], '@module' => $field_type['provider']));
 
     $usage = array();
     foreach ($field_storage->getBundles() as $bundle) {
-      if ($route_info = FieldUI::getOverviewRouteInfo($field_storage->entity_type, $bundle)) {
-        $usage[] = \Drupal::l($this->bundles[$field_storage->entity_type][$bundle]['label'], $route_info);
+      $entity_type_id = $field_storage->getTargetEntityTypeId();
+      if ($route_info = FieldUI::getOverviewRouteInfo($entity_type_id, $bundle)) {
+        $usage[] = \Drupal::l($this->bundles[$entity_type_id][$bundle]['label'], $route_info);
       }
       else {
-        $usage[] = $this->bundles[$field_storage->entity_type][$bundle]['label'];
+        $usage[] = $this->bundles[$entity_type_id][$bundle]['label'];
       }
     }
     $usage_escaped = '';
diff --git a/core/modules/field_ui/src/Form/FieldConfigDeleteForm.php b/core/modules/field_ui/src/Form/FieldConfigDeleteForm.php
index 4afe0e3c493867f4696c3f65c674f40438af77bc..5baa57d16becdade6a1ce67edd21a713da93ed7d 100644
--- a/core/modules/field_ui/src/Form/FieldConfigDeleteForm.php
+++ b/core/modules/field_ui/src/Form/FieldConfigDeleteForm.php
@@ -59,7 +59,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
     $bundles = $this->entityManager->getBundleInfo($this->entity->entity_type);
     $bundle_label = $bundles[$this->entity->bundle]['label'];
 
-    if ($field_storage && !$field_storage->locked) {
+    if ($field_storage && !$field_storage->isLocked()) {
       $this->entity->delete();
       drupal_set_message($this->t('The field %field has been deleted from the %type content type.', array('%field' => $this->entity->label(), '%type' => $bundle_label)));
     }
diff --git a/core/modules/field_ui/src/Form/FieldStorageEditForm.php b/core/modules/field_ui/src/Form/FieldStorageEditForm.php
index a89f0a753257cbe4baedee683040dc0010eadec8..92ddca16f29609a57cfab4a7eb0ac22a27d5c9d3 100644
--- a/core/modules/field_ui/src/Form/FieldStorageEditForm.php
+++ b/core/modules/field_ui/src/Form/FieldStorageEditForm.php
@@ -155,7 +155,7 @@ public function buildForm(array $form, FormStateInterface $form_state, FieldConf
     // Build the non-configurable field values.
     $form['field_storage']['field_name'] = array('#type' => 'value', '#value' => $field_storage->getName());
     $form['field_storage']['type'] = array('#type' => 'value', '#value' => $field_storage->getType());
-    $form['field_storage']['module'] = array('#type' => 'value', '#value' => $field_storage->module);
+    $form['field_storage']['module'] = array('#type' => 'value', '#value' => $field_storage->getTypeProvider());
     $form['field_storage']['translatable'] = array('#type' => 'value', '#value' => $field_storage->isTranslatable());
 
     $form['actions'] = array('#type' => 'actions');
@@ -199,7 +199,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
     // Merge incoming form values into the existing field.
     $field_storage = $this->field->getFieldStorageDefinition();
     foreach ($field_values as $key => $value) {
-      $field_storage->{$key} = $value;
+      $field_storage->set($key, $value);
     }
 
     // Update the field.
diff --git a/core/modules/field_ui/src/Tests/EntityDisplayTest.php b/core/modules/field_ui/src/Tests/EntityDisplayTest.php
index 3bec41b68773a235d396a1ea1f4b93370cd0c5ea..c26b962b40d583890ce5f69efc52999982d536dc 100644
--- a/core/modules/field_ui/src/Tests/EntityDisplayTest.php
+++ b/core/modules/field_ui/src/Tests/EntityDisplayTest.php
@@ -173,7 +173,7 @@ public function testFieldComponent() {
 
     // Check that providing no options results in default values being used.
     $display->setComponent($field_name);
-    $field_type_info = \Drupal::service('plugin.manager.field.field_type')->getDefinition($field_storage->type);
+    $field_type_info = \Drupal::service('plugin.manager.field.field_type')->getDefinition($field_storage->getType());
     $default_formatter = $field_type_info['default_formatter'];
     $formatter_settings =  \Drupal::service('plugin.manager.field.formatter')->getDefaultSettings($default_formatter);
     $expected = array(
diff --git a/core/modules/field_ui/src/Tests/EntityFormDisplayTest.php b/core/modules/field_ui/src/Tests/EntityFormDisplayTest.php
index 0bd3e2b85ff1195907d174fc8532f394bfe8e0fb..6e84b95c610cac8c04e889a42f14e900ef290e31 100644
--- a/core/modules/field_ui/src/Tests/EntityFormDisplayTest.php
+++ b/core/modules/field_ui/src/Tests/EntityFormDisplayTest.php
@@ -74,7 +74,7 @@ public function testFieldComponent() {
 
     // Check that providing no options results in default values being used.
     $form_display->setComponent($field_name);
-    $field_type_info = \Drupal::service('plugin.manager.field.field_type')->getDefinition($field_storage->type);
+    $field_type_info = \Drupal::service('plugin.manager.field.field_type')->getDefinition($field_storage->getType());
     $default_widget = $field_type_info['default_widget'];
     $widget_settings = \Drupal::service('plugin.manager.field.widget')->getDefaultSettings($default_widget);
     $expected = array(
diff --git a/core/modules/field_ui/src/Tests/ManageFieldsTest.php b/core/modules/field_ui/src/Tests/ManageFieldsTest.php
index 80dbfb93a865540823a21bf5cf8595a925894e04..1a42ce5905dbac2b9dc4a218ddce19d216628b2f 100644
--- a/core/modules/field_ui/src/Tests/ManageFieldsTest.php
+++ b/core/modules/field_ui/src/Tests/ManageFieldsTest.php
@@ -396,7 +396,7 @@ function testDefaultValue() {
     // Check that the default value can be empty when the field is marked as
     // required and can store unlimited values.
     $field_storage = FieldStorageConfig::loadByName('node', $field_name);
-    $field_storage->cardinality = FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED;
+    $field_storage->setCardinality(FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED);
     $field_storage->save();
 
     $this->drupalGet($admin_path);
diff --git a/core/modules/file/file.views.inc b/core/modules/file/file.views.inc
index a8fc0fe755cb472bf757aa2f7e1b02c8a71f8fcb..870a76a9b705590a1d00b7d9914d96db83693763 100644
--- a/core/modules/file/file.views.inc
+++ b/core/modules/file/file.views.inc
@@ -37,7 +37,7 @@ function file_field_views_data(FieldStorageConfigInterface $field_storage) {
  * Views integration to provide reverse relationships on file fields.
  */
 function file_field_views_data_views_data_alter(array &$data, FieldStorageConfigInterface $field_storage) {
-  $entity_type_id = $field_storage->entity_type;
+  $entity_type_id = $field_storage->getTargetEntityTypeId();
   $entity_manager = \Drupal::entityManager();
   $entity_type = $entity_manager->getDefinition($entity_type_id);
   $field_name = $field_storage->getName();
diff --git a/core/modules/image/image.module b/core/modules/image/image.module
index 76710300b284421e2e63fa5a04aabbb66f06a1c3..cc326b3e3e58fc5220a75325c00a6fd75a2d0161 100644
--- a/core/modules/image/image.module
+++ b/core/modules/image/image.module
@@ -7,6 +7,7 @@
 
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\field\Entity\FieldConfig;
 use Drupal\file\Entity\File;
 use Drupal\field\FieldStorageConfigInterface;
 use Drupal\field\FieldConfigInterface;
@@ -321,49 +322,51 @@ function image_filter_keyword($value, $current_pixels, $new_pixels) {
  * Transforms default image of image field from array into single value at save.
  */
 function image_entity_presave(EntityInterface $entity) {
-  $field_storage = FALSE;
-  $entity_type_id = $entity->getEntityTypeId();
-  if ($entity_type_id == 'field_config') {
-    $field_storage = $entity->getFieldStorageDefinition();
-    $default_settings = \Drupal::service('plugin.manager.field.field_type')->getDefaultFieldSettings('image');
+  // Get the default image settings, return if not saving an image field storage
+  // or image field entity.
+  if (($entity instanceof FieldStorageConfigInterface || $entity instanceof FieldConfigInterface) && $entity->getType() == 'image') {
+    $default_image = $entity->getSetting('default_image');
   }
-  elseif ($entity_type_id == 'field_storage_config') {
-    $field_storage = $entity;
-    $default_settings = \Drupal::service('plugin.manager.field.field_type')->getDefaultStorageSettings('image');
-  }
-  // Exit, if not saving an image field storage or image field entity.
-  if (!$field_storage || $field_storage->type != 'image') {
+  else {
     return;
   }
 
-  if ($field_storage->isSyncing()) {
+  if ($entity->isSyncing()) {
     return;
   }
 
-  $uuid = $entity->settings['default_image']['uuid'];
+  $uuid = $default_image['uuid'];
   if ($uuid) {
-    $original_uuid = isset($entity->original) ? $entity->original->settings['default_image']['uuid'] : NULL;
+    $original_uuid = isset($entity->original) ? $entity->original->getSetting('default_image')['uuid'] : NULL;
     if ($uuid != $original_uuid) {
       $file = \Drupal::entityManager()->loadEntityByUuid('file', $uuid);
       if ($file) {
         $image = \Drupal::service('image.factory')->get($file->getFileUri());
-        $entity->settings['default_image']['width'] = $image->getWidth();
-        $entity->settings['default_image']['height'] = $image->getHeight();
+        $default_image['width'] = $image->getWidth();
+        $default_image['height'] = $image->getHeight();
       }
       else {
-        $entity->settings['default_image']['uuid'] = NULL;
+        $default_image['uuid'] = NULL;
       }
     }
   }
 
-  $entity->settings['default_image'] += $default_settings['default_image'];
+  // @todo Simplify this in https://www.drupal.org/node/2030637, when both
+  //   interfaces have a setSetting() method.
+  if ($entity instanceof FieldStorageConfigInterface) {
+    $entity->setSetting('default_image', $default_image);
+  }
+  elseif ($entity instanceof FieldConfig) {
+    $entity->settings['default_image'] = $default_image;
+  }
+
 }
 
 /**
  * Implements hook_ENTITY_TYPE_update() for 'field_storage_config'.
  */
 function image_field_storage_config_update(FieldStorageConfigInterface $field_storage) {
-  if ($field_storage->type != 'image') {
+  if ($field_storage->getType() != 'image') {
     // Only act on image fields.
     return;
   }
@@ -371,8 +374,8 @@ function image_field_storage_config_update(FieldStorageConfigInterface $field_st
   $prior_field_storage = $field_storage->original;
 
   // The value of a managed_file element can be an array if #extended == TRUE.
-  $uuid_new = $field_storage->settings['default_image']['uuid'];
-  $uuid_old = $prior_field_storage->settings['default_image']['uuid'];
+  $uuid_new = $field_storage->getSetting('default_image')['uuid'];
+  $uuid_old = $prior_field_storage->getSetting('default_image')['uuid'];
 
   $file_new = $uuid_new ? \Drupal::entityManager()->loadEntityByUuid('file', $uuid_new) : FALSE;
 
@@ -392,8 +395,8 @@ function image_field_storage_config_update(FieldStorageConfigInterface $field_st
   }
 
   // If the upload destination changed, then move the file.
-  if ($file_new && (file_uri_scheme($file_new->getFileUri()) != $field_storage->settings['uri_scheme'])) {
-    $directory = $field_storage->settings['uri_scheme'] . '://default_images/';
+  if ($file_new && (file_uri_scheme($file_new->getFileUri()) != $field_storage->getSetting('uri_scheme'))) {
+    $directory = $field_storage->getSetting('uri_scheme') . '://default_images/';
     file_prepare_directory($directory, FILE_CREATE_DIRECTORY);
     file_move($file_new, $directory . $file_new->filename);
   }
@@ -404,14 +407,14 @@ function image_field_storage_config_update(FieldStorageConfigInterface $field_st
  */
 function image_field_config_update(FieldConfigInterface $field) {
   $field_storage = $field->getFieldStorageDefinition();
-  if ($field_storage->type != 'image') {
+  if ($field_storage->getType() != 'image') {
     // Only act on image fields.
     return;
   }
 
   $prior_instance = $field->original;
 
-  $uuid_new = $field->settings['default_image']['uuid'];
+  $uuid_new = $field->getSetting('default_image')['uuid'];
   $uuid_old = $prior_instance->settings['default_image']['uuid'];
 
   // If the old and new files do not match, update the default accordingly.
@@ -430,8 +433,8 @@ function image_field_config_update(FieldConfigInterface $field) {
   }
 
   // If the upload destination changed, then move the file.
-  if ($file_new && (file_uri_scheme($file_new->getFileUri()) != $field_storage->settings['uri_scheme'])) {
-    $directory = $field_storage->settings['uri_scheme'] . '://default_images/';
+  if ($file_new && (file_uri_scheme($file_new->getFileUri()) != $field_storage->getSetting('uri_scheme'))) {
+    $directory = $field_storage->getSetting('uri_scheme') . '://default_images/';
     file_prepare_directory($directory, FILE_CREATE_DIRECTORY);
     file_move($file_new, $directory . $file_new->filename);
   }
@@ -441,13 +444,13 @@ function image_field_config_update(FieldConfigInterface $field) {
  * Implements hook_ENTITY_TYPE_delete() for 'field_storage_config'.
  */
 function image_field_storage_config_delete(FieldStorageConfigInterface $field) {
-  if ($field->type != 'image') {
+  if ($field->getType() != 'image') {
     // Only act on image fields.
     return;
   }
 
   // The value of a managed_file element can be an array if #extended == TRUE.
-  $uuid = $field->settings['default_image']['uuid'];
+  $uuid = $field->getSetting('default_image')['uuid'];
   if ($uuid && ($file = \Drupal::entityManager()->loadEntityByUuid('file', $uuid))) {
     \Drupal::service('file.usage')->delete($file, 'image', 'default_image', $field->uuid());
   }
@@ -458,7 +461,7 @@ function image_field_storage_config_delete(FieldStorageConfigInterface $field) {
  */
 function image_field_config_delete(FieldConfigInterface $field) {
   $field_storage = $field->getFieldStorageDefinition();
-  if ($field_storage->type != 'image') {
+  if ($field_storage->getType() != 'image') {
     // Only act on image fields.
     return;
   }
diff --git a/core/modules/image/src/Tests/ImageFieldDefaultImagesTest.php b/core/modules/image/src/Tests/ImageFieldDefaultImagesTest.php
index a546590d421ded22eb1a4b65ca1ef851d97851e9..ce1e15f4987bf107584a05bac52d411b30e2f037 100644
--- a/core/modules/image/src/Tests/ImageFieldDefaultImagesTest.php
+++ b/core/modules/image/src/Tests/ImageFieldDefaultImagesTest.php
@@ -175,7 +175,9 @@ public function testDefaultImages() {
     );
 
     // Upload a new default for the field storage.
-    $field_storage->settings['default_image']['uuid'] = $default_images['field_new']->uuid();
+    $default_image_settings = $field_storage->getSetting('default_image');
+    $default_image_settings['uuid'] = $default_images['field_new']->uuid();
+    $field_storage->setSetting('default_image', $default_image_settings);
     $field_storage->save();
 
     // Confirm that the new default is used on the article field settings form.
diff --git a/core/modules/migrate_drupal/src/Tests/d6/MigrateFieldTest.php b/core/modules/migrate_drupal/src/Tests/d6/MigrateFieldTest.php
index 296ae36de99d0275290d4e7060417b896e62c0ec..bb919625ef1887760cef9bd9507e373ba13a6337 100644
--- a/core/modules/migrate_drupal/src/Tests/d6/MigrateFieldTest.php
+++ b/core/modules/migrate_drupal/src/Tests/d6/MigrateFieldTest.php
@@ -52,27 +52,27 @@ public function testFields() {
     /** @var \Drupal\field\Entity\FieldStorageConfig $field_storage */
     $field_storage = FieldStorageConfig::load('node.field_test');
     $expected = array('max_length' => 255);
-    $this->assertIdentical($field_storage->type, "text",  t('Field type is @fieldtype. It should be text.', array('@fieldtype' => $field_storage->type)));
-    $this->assertIdentical($field_storage->settings, $expected, "Field type text settings are correct");
+    $this->assertIdentical($field_storage->getType(), "text",  t('Field type is @fieldtype. It should be text.', array('@fieldtype' => $field_storage->getType())));
+    $this->assertIdentical($field_storage->getSettings(), $expected, "Field type text settings are correct");
 
     // Integer field.
     $field_storage = FieldStorageConfig::load('node.field_test_two');
-    $this->assertIdentical($field_storage->type, "integer",  t('Field type is @fieldtype. It should be integer.', array('@fieldtype' => $field_storage->type)));
+    $this->assertIdentical($field_storage->getType(), "integer",  t('Field type is @fieldtype. It should be integer.', array('@fieldtype' => $field_storage->getType())));
 
     // Float field.
     $field_storage = FieldStorageConfig::load('node.field_test_three');
-    $this->assertIdentical($field_storage->type, "decimal",  t('Field type is @fieldtype. It should be decimal.', array('@fieldtype' => $field_storage->type)));
+    $this->assertIdentical($field_storage->getType(), "decimal",  t('Field type is @fieldtype. It should be decimal.', array('@fieldtype' => $field_storage->getType())));
 
     // Link field.
     $field_storage = FieldStorageConfig::load('node.field_test_link');
-    $this->assertIdentical($field_storage->type, "link",  t('Field type is @fieldtype. It should be link.', array('@fieldtype' => $field_storage->type)));
+    $this->assertIdentical($field_storage->getType(), "link",  t('Field type is @fieldtype. It should be link.', array('@fieldtype' => $field_storage->getType())));
 
     // File field.
     $field_storage = FieldStorageConfig::load('node.field_test_filefield');
-    $this->assertIdentical($field_storage->type, "file",  t('Field type is @fieldtype. It should be file.', array('@fieldtype' => $field_storage->type)));
+    $this->assertIdentical($field_storage->getType(), "file",  t('Field type is @fieldtype. It should be file.', array('@fieldtype' => $field_storage->getType())));
 
     $field_storage = FieldStorageConfig::load('node.field_test_imagefield');
-    $this->assertIdentical($field_storage->type, "image",  t('Field type is @fieldtype. It should be image.', array('@fieldtype' => $field_storage->type)));
+    $this->assertIdentical($field_storage->getType(), "image",  t('Field type is @fieldtype. It should be image.', array('@fieldtype' => $field_storage->getType())));
     $settings = $field_storage->getSettings();
     $this->assertIdentical($settings['target_type'], 'file');
     $this->assertIdentical($settings['uri_scheme'], 'public');
@@ -80,39 +80,39 @@ public function testFields() {
 
     // Phone field.
     $field_storage = FieldStorageConfig::load('node.field_test_phone');
-    $this->assertIdentical($field_storage->type, "telephone",  t('Field type is @fieldtype. It should be telephone.', array('@fieldtype' => $field_storage->type)));
+    $this->assertIdentical($field_storage->getType(), "telephone",  t('Field type is @fieldtype. It should be telephone.', array('@fieldtype' => $field_storage->getType())));
 
     // Date field.
     $field_storage = FieldStorageConfig::load('node.field_test_datetime');
-    $this->assertIdentical($field_storage->type, "datetime",  t('Field type is @fieldtype. It should be datetime.', array('@fieldtype' => $field_storage->type)));
+    $this->assertIdentical($field_storage->getType(), "datetime",  t('Field type is @fieldtype. It should be datetime.', array('@fieldtype' => $field_storage->getType())));
 
     // Decimal field with radio buttons.
     $field_storage = FieldStorageConfig::load('node.field_test_decimal_radio_buttons');
-    $this->assertIdentical($field_storage->type, "list_float",  t('Field type is @fieldtype. It should be list_float.', array('@fieldtype' => $field_storage->type)));
-    $this->assertNotNull($field_storage->settings['allowed_values']['1.2'], t('First allowed value key is set to 1.2'));
-    $this->assertNotNull($field_storage->settings['allowed_values']['2.1'], t('Second allowed value key is set to 2.1'));
-    $this->assertIdentical($field_storage->settings['allowed_values']['1.2'], '1.2', t('First allowed value is set to 1.2'));
-    $this->assertIdentical($field_storage->settings['allowed_values']['2.1'], '2.1', t('Second allowed value is set to 1.2'));
+    $this->assertIdentical($field_storage->getType(), "list_float",  t('Field type is @fieldtype. It should be list_float.', array('@fieldtype' => $field_storage->getType())));
+    $this->assertNotNull($field_storage->getSetting('allowed_values')['1.2'], t('First allowed value key is set to 1.2'));
+    $this->assertNotNull($field_storage->getSetting('allowed_values')['2.1'], t('Second allowed value key is set to 2.1'));
+    $this->assertIdentical($field_storage->getSetting('allowed_values')['1.2'], '1.2', t('First allowed value is set to 1.2'));
+    $this->assertIdentical($field_storage->getSetting('allowed_values')['2.1'], '2.1', t('Second allowed value is set to 1.2'));
 
     // Float field with a single checkbox.
     $field_storage = FieldStorageConfig::load('node.field_test_float_single_checkbox');
-    $this->assertIdentical($field_storage->type, "boolean",  t('Field type is @fieldtype. It should be boolean.', array('@fieldtype' => $field_storage->type)));
+    $this->assertIdentical($field_storage->getType(), "boolean",  t('Field type is @fieldtype. It should be boolean.', array('@fieldtype' => $field_storage->getType())));
 
     // Integer field with a select list.
     $field_storage = FieldStorageConfig::load('node.field_test_integer_selectlist');
-    $this->assertIdentical($field_storage->type, "list_integer",  t('Field type is @fieldtype. It should be list_integer.', array('@fieldtype' => $field_storage->type)));
-    $this->assertNotNull($field_storage->settings['allowed_values']['1234'], t('First allowed value key is set to 1234'));
-    $this->assertNotNull($field_storage->settings['allowed_values']['2341'], t('Second allowed value key is set to 2341'));
-    $this->assertNotNull($field_storage->settings['allowed_values']['3412'], t('Third allowed value key is set to 3412'));
-    $this->assertNotNull($field_storage->settings['allowed_values']['4123'], t('Fourth allowed value key is set to 4123'));
-    $this->assertIdentical($field_storage->settings['allowed_values']['1234'], '1234', t('First allowed value is set to 1234'));
-    $this->assertIdentical($field_storage->settings['allowed_values']['2341'], '2341', t('Second allowed value is set to 2341'));
-    $this->assertIdentical($field_storage->settings['allowed_values']['3412'], '3412', t('Third allowed value is set to 3412'));
-    $this->assertIdentical($field_storage->settings['allowed_values']['4123'], '4123', t('Fourth allowed value is set to 4123'));
+    $this->assertIdentical($field_storage->getType(), "list_integer",  t('Field type is @fieldtype. It should be list_integer.', array('@fieldtype' => $field_storage->getType())));
+    $this->assertNotNull($field_storage->getSetting('allowed_values')['1234'], t('First allowed value key is set to 1234'));
+    $this->assertNotNull($field_storage->getSetting('allowed_values')['2341'], t('Second allowed value key is set to 2341'));
+    $this->assertNotNull($field_storage->getSetting('allowed_values')['3412'], t('Third allowed value key is set to 3412'));
+    $this->assertNotNull($field_storage->getSetting('allowed_values')['4123'], t('Fourth allowed value key is set to 4123'));
+    $this->assertIdentical($field_storage->getSetting('allowed_values')['1234'], '1234', t('First allowed value is set to 1234'));
+    $this->assertIdentical($field_storage->getSetting('allowed_values')['2341'], '2341', t('Second allowed value is set to 2341'));
+    $this->assertIdentical($field_storage->getSetting('allowed_values')['3412'], '3412', t('Third allowed value is set to 3412'));
+    $this->assertIdentical($field_storage->getSetting('allowed_values')['4123'], '4123', t('Fourth allowed value is set to 4123'));
 
     // Text field with a single checkbox.
     $field_storage = FieldStorageConfig::load('node.field_test_text_single_checkbox');
-    $this->assertIdentical($field_storage->type, "boolean",  t('Field type is @fieldtype. It should be boolean.', array('@fieldtype' => $field_storage->type)));
+    $this->assertIdentical($field_storage->getType(), "boolean",  t('Field type is @fieldtype. It should be boolean.', array('@fieldtype' => $field_storage->getType())));
 
   }
 
diff --git a/core/modules/migrate_drupal/src/Tests/d6/MigrateUserProfileFieldTest.php b/core/modules/migrate_drupal/src/Tests/d6/MigrateUserProfileFieldTest.php
index 35644cea55430dc0c767b84be0a139a5634d7718..79a936259ef2ba8c31905b5b83fa57601223bd6e 100644
--- a/core/modules/migrate_drupal/src/Tests/d6/MigrateUserProfileFieldTest.php
+++ b/core/modules/migrate_drupal/src/Tests/d6/MigrateUserProfileFieldTest.php
@@ -44,20 +44,20 @@ protected function setUp() {
   public function testUserProfileFields() {
     // Migrated a text field.
     $field_storage = FieldStorageConfig::load('user.profile_color');
-    $this->assertIdentical($field_storage->type, 'text', 'Field type is text.');
-    $this->assertIdentical($field_storage->cardinality, 1, 'Text field has correct cardinality');
+    $this->assertIdentical($field_storage->getType(), 'text', 'Field type is text.');
+    $this->assertIdentical($field_storage->getCardinality(), 1, 'Text field has correct cardinality');
 
     // Migrated a textarea.
     $field_storage = FieldStorageConfig::load('user.profile_biography');
-    $this->assertIdentical($field_storage->type, 'text_long', 'Field type is text_long.');
+    $this->assertIdentical($field_storage->getType(), 'text_long', 'Field type is text_long.');
 
     // Migrated checkbox field.
     $field_storage = FieldStorageConfig::load('user.profile_sell_address');
-    $this->assertIdentical($field_storage->type, 'boolean', 'Field type is boolean.');
+    $this->assertIdentical($field_storage->getType(), 'boolean', 'Field type is boolean.');
 
     // Migrated selection field.
     $field_storage = FieldStorageConfig::load('user.profile_sold_to');
-    $this->assertIdentical($field_storage->type, 'list_string', 'Field type is list_string.');
+    $this->assertIdentical($field_storage->getType(), 'list_string', 'Field type is list_string.');
     $settings = $field_storage->getSettings();
     $this->assertIdentical($settings['allowed_values'], array(
       'Pill spammers' => 'Pill spammers',
@@ -68,23 +68,23 @@ public function testUserProfileFields() {
       'Faithful servant' => 'Faithful servant',
       'Anonymous donor' => 'Anonymous donor',
     ));
-    $this->assertIdentical($field_storage->type, 'list_string', 'Field type is list_string.');
+    $this->assertIdentical($field_storage->getType(), 'list_string', 'Field type is list_string.');
 
     // Migrated list field.
     $field_storage = FieldStorageConfig::load('user.profile_bands');
-    $this->assertIdentical($field_storage->type, 'text', 'Field type is text.');
-    $this->assertIdentical($field_storage->cardinality, -1, 'List field has correct cardinality');
+    $this->assertIdentical($field_storage->getType(), 'text', 'Field type is text.');
+    $this->assertIdentical($field_storage->getCardinality(), -1, 'List field has correct cardinality');
 
 /*
     // Migrated URL field.
     $field_storage = FieldStorageConfig::load('user.profile_blog');
-    $this->assertIdentical($field_storage->type, 'link', 'Field type is link.');
+    $this->assertIdentical($field_storage->getType(), 'link', 'Field type is link.');
 */
 
     // Migrated date field.
     $field_storage = FieldStorageConfig::load('user.profile_birthdate');
-    $this->assertIdentical($field_storage->type, 'datetime', 'Field type is datetime.');
-    $this->assertIdentical($field_storage->settings['datetime_type'], 'date');
+    $this->assertIdentical($field_storage->getType(), 'datetime', 'Field type is datetime.');
+    $this->assertIdentical($field_storage->getSettings()['datetime_type'], 'date');
   }
 
 }
diff --git a/core/modules/node/src/Tests/NodeFieldMultilingualTest.php b/core/modules/node/src/Tests/NodeFieldMultilingualTest.php
index dc8897b11bbeb372dce0f6ad5cee5c0b8f20b3e9..dd8aec223dae1f1950e28d419b68daefca7b24d5 100644
--- a/core/modules/node/src/Tests/NodeFieldMultilingualTest.php
+++ b/core/modules/node/src/Tests/NodeFieldMultilingualTest.php
@@ -53,7 +53,7 @@ protected function setUp() {
 
     // Make node body translatable.
     $field_storage = FieldStorageConfig::loadByName('node', 'body');
-    $field_storage->translatable = TRUE;
+    $field_storage->setTranslatable(TRUE);
     $field_storage->save();
   }
 
diff --git a/core/modules/node/src/Tests/Views/NodeLanguageTest.php b/core/modules/node/src/Tests/Views/NodeLanguageTest.php
index 0195b447ead237a56bc11e7e539cdce038330307..4ced144692a44e07159d1940fb901a5e90205ccb 100644
--- a/core/modules/node/src/Tests/Views/NodeLanguageTest.php
+++ b/core/modules/node/src/Tests/Views/NodeLanguageTest.php
@@ -57,7 +57,7 @@ protected function setUp() {
     // Make the body field translatable. The title is already translatable by
     // definition.
     $field_storage = FieldStorageConfig::loadByName('node', 'body');
-    $field_storage->translatable = TRUE;
+    $field_storage->setTranslatable(TRUE);
     $field_storage->save();
 
     // Set up node titles. They should not include the words "French",
diff --git a/core/modules/options/options.module b/core/modules/options/options.module
index a2e8f06aefc9c2eccaa9c608533a124f7675be1d..d221adbe1d07e0901a419ded758490b3e7ed3184 100644
--- a/core/modules/options/options.module
+++ b/core/modules/options/options.module
@@ -106,12 +106,12 @@ function options_allowed_values(FieldStorageDefinitionInterface $definition, Fie
  * Implements hook_field_storage_config_update_forbid().
  */
 function options_field_storage_config_update_forbid(FieldStorageConfigInterface $field_storage, FieldStorageConfigInterface $prior_field_storage) {
-  if ($field_storage->module == 'options' && $field_storage->hasData()) {
+  if ($field_storage->getTypeProvider() == 'options' && $field_storage->hasData()) {
     // Forbid any update that removes allowed values with actual data.
     $allowed_values = $field_storage->getSetting('allowed_values');
     $prior_allowed_values = $prior_field_storage->getSetting('allowed_values');
     $lost_keys = array_keys(array_diff_key($prior_allowed_values, $allowed_values));
-    if (_options_values_in_use($field_storage->entity_type, $field_storage->getName(), $lost_keys)) {
+    if (_options_values_in_use($field_storage->getTargetEntityTypeId(), $field_storage->getName(), $lost_keys)) {
       throw new FieldStorageDefinitionUpdateForbiddenException(t('A list field (@field_name) with existing data cannot have its keys changed.', array('@field_name' => $field_storage->getName())));
     }
   }
diff --git a/core/modules/options/options.views.inc b/core/modules/options/options.views.inc
index 95b8474c205267de3dcb87145caf2c2e3eb4ac48..8eb35c28ab421845b5f39aa8f070c3a940f54cfa 100644
--- a/core/modules/options/options.views.inc
+++ b/core/modules/options/options.views.inc
@@ -7,6 +7,8 @@
  * @ingroup views_module_handlers
  */
 
+use Drupal\field\FieldStorageConfigInterface;
+
 /**
  * Implements hook_field_views_data().
  *
@@ -14,7 +16,7 @@
  * argument handlers for list fields. This should allow to select values of
  * the list.
  */
-function options_field_views_data($field) {
+function options_field_views_data(FieldStorageConfigInterface $field) {
   $data = views_field_default_views_data($field);
 
   $function = $field->getSetting('allowed_values_function');
@@ -29,7 +31,7 @@ function options_field_views_data($field) {
         $data[$table_name][$field_name]['filter']['id'] = 'list_field';
       }
       if (isset($field_data['argument']) && $field_name != 'delta') {
-        if ($field->type == 'list_string') {
+        if ($field->getType() == 'list_string') {
           $data[$table_name][$field_name]['argument']['id'] = 'string_list_field';
         }
         else {
diff --git a/core/modules/options/src/Tests/OptionsFieldTest.php b/core/modules/options/src/Tests/OptionsFieldTest.php
index a6f0b97eb00f80174f24061a2ec68f50cdaebebb..5ad59539cda887e7ef108973e8c3474cf9c3b85e 100644
--- a/core/modules/options/src/Tests/OptionsFieldTest.php
+++ b/core/modules/options/src/Tests/OptionsFieldTest.php
@@ -39,7 +39,7 @@ function testUpdateAllowedValues() {
     $entity = entity_create('entity_test');
     $entity->{$this->fieldName}->value = 1;
     $entity->save();
-    $this->fieldStorage->settings['allowed_values'] = array(2 => 'Two');
+    $this->fieldStorage->setSetting('allowed_values', [2 => 'Two']);
     try {
       $this->fieldStorage->save();
       $this->fail(t('Cannot update a list field storage to not include keys with existing data.'));
@@ -52,7 +52,7 @@ function testUpdateAllowedValues() {
     $entity->save();
 
     // Removed options do not appear.
-    $this->fieldStorage->settings['allowed_values'] = array(2 => 'Two');
+    $this->fieldStorage->setSetting('allowed_values', [2 => 'Two']);
     $this->fieldStorage->save();
     $entity = entity_create('entity_test');
     $form = \Drupal::service('entity.form_builder')->getForm($entity);
@@ -61,7 +61,7 @@ function testUpdateAllowedValues() {
     $this->assertTrue(empty($form[$this->fieldName]['widget'][3]), 'Option 3 does not exist');
 
     // Completely new options appear.
-    $this->fieldStorage->settings['allowed_values'] = array(10 => 'Update', 20 => 'Twenty');
+    $this->fieldStorage->setSetting('allowed_values', [10 => 'Update', 20 => 'Twenty']);
     $this->fieldStorage->save();
     // The entity holds an outdated field object with the old allowed values
     // setting, so we need to reintialize the entity object.
diff --git a/core/modules/options/src/Tests/OptionsWidgetsTest.php b/core/modules/options/src/Tests/OptionsWidgetsTest.php
index 3c2b68b065a0d5e4c3d482c6ee0876253ecd5769..0de54a5d5c7f5ee50032a04de2f47ea723dc63c9 100644
--- a/core/modules/options/src/Tests/OptionsWidgetsTest.php
+++ b/core/modules/options/src/Tests/OptionsWidgetsTest.php
@@ -132,7 +132,7 @@ function testRadioButtons() {
     $this->assertFieldValues($entity_init, 'card_1', array());
 
     // Check that required radios with one option is auto-selected.
-    $this->card1->settings['allowed_values'] = [99 => 'Only allowed value'];
+    $this->card1->setSetting('allowed_values', [99 => 'Only allowed value']);
     $this->card1->save();
     $field->required = TRUE;
     $field->save();
@@ -221,7 +221,7 @@ function testCheckBoxes() {
     $this->assertFieldValues($entity_init, 'card_2', array());
 
     // Required checkbox with one option is auto-selected.
-    $this->card2->settings['allowed_values'] = array(99 => 'Only allowed value');
+    $this->card2->setSetting('allowed_values', [99 => 'Only allowed value']);
     $this->card2->save();
     $field->required = TRUE;
     $field->save();
@@ -299,8 +299,8 @@ function testSelectListSingle() {
 
     // Test optgroups.
 
-    $this->card1->settings['allowed_values'] = array();
-    $this->card1->settings['allowed_values_function'] = 'options_test_allowed_values_callback';
+    $this->card1->setSetting('allowed_values', []);
+    $this->card1->setSetting('allowed_values_function', 'options_test_allowed_values_callback');
     $this->card1->save();
 
     // Display form: with no field data, nothing is selected
@@ -418,8 +418,8 @@ function testSelectListMultiple() {
     // Test optgroups.
 
     // Use a callback function defining optgroups.
-    $this->card2->settings['allowed_values'] = array();
-    $this->card2->settings['allowed_values_function'] = 'options_test_allowed_values_callback';
+    $this->card2->setSetting('allowed_values', []);
+    $this->card2->setSetting('allowed_values_function', 'options_test_allowed_values_callback');
     $this->card2->save();
     $field->required = FALSE;
     $field->save();
diff --git a/core/modules/quickedit/src/Tests/EditorSelectionTest.php b/core/modules/quickedit/src/Tests/EditorSelectionTest.php
index 336fbecb9295a95eadb8ec190a2f9e681b27d7d0..d1484080c3ef88e74ee2a01c312155e426a5c2ac 100644
--- a/core/modules/quickedit/src/Tests/EditorSelectionTest.php
+++ b/core/modules/quickedit/src/Tests/EditorSelectionTest.php
@@ -74,7 +74,7 @@ public function testText() {
     $this->assertEqual('plain_text', $this->getSelectedEditor($entity->id(), $field_name), "With cardinality 1, the 'plain_text' editor is selected.");
 
     // With cardinality >1
-    $this->fields->field_text_field_storage->cardinality = 2;
+    $this->fields->field_text_field_storage->setCardinality(2);
     $this->fields->field_text_field_storage->save();
     $this->assertEqual('form', $this->getSelectedEditor($entity->id(), $field_name), "With cardinality >1, the 'form' editor is selected.");
 
@@ -119,7 +119,7 @@ public function testTextWysiwyg() {
     $this->assertEqual('wysiwyg', $this->getSelectedEditor($entity->id(), $field_name), "With cardinality 1, and the full_html text format, the 'wysiwyg' editor is selected.");
 
     // Editor selection with text field, cardinality >1.
-    $this->fields->field_textarea_field_storage->cardinality = 2;
+    $this->fields->field_textarea_field_storage->setCardinality(2);
     $this->fields->field_textarea_field_storage->save();
     $this->assertEqual('form', $this->getSelectedEditor($entity->id(), $field_name), "With cardinality >1, and both items using the full_html text format, the 'form' editor is selected.");
   }
@@ -150,7 +150,7 @@ public function testNumber() {
     $this->assertEqual('form', $this->getSelectedEditor($entity->id(), $field_name), "With cardinality 1, the 'form' editor is selected.");
 
     // Editor selection with cardinality >1.
-    $this->fields->field_nr_field_storage->cardinality = 2;
+    $this->fields->field_nr_field_storage->setCardinality(2);
     $this->fields->field_nr_field_storage->save();
     $this->assertEqual('form', $this->getSelectedEditor($entity->id(), $field_name), "With cardinality >1, the 'form' editor is selected.");
   }
diff --git a/core/modules/search/src/Tests/SearchLanguageTest.php b/core/modules/search/src/Tests/SearchLanguageTest.php
index b6f8d2b8ce3ab7b8abbcb58483448024103b573d..f4acf9ca3c93a387c862d0fd2d9bbbb2ad7d4016 100644
--- a/core/modules/search/src/Tests/SearchLanguageTest.php
+++ b/core/modules/search/src/Tests/SearchLanguageTest.php
@@ -45,7 +45,7 @@ protected function setUp() {
     // definition. The parent class has already created the article and page
     // content types.
     $field_storage = FieldStorageConfig::loadByName('node', 'body');
-    $field_storage->translatable = TRUE;
+    $field_storage->setTranslatable(TRUE);
     $field_storage->save();
 
     // Create a few page nodes with multilingual body values.
diff --git a/core/modules/search/src/Tests/SearchMultilingualEntityTest.php b/core/modules/search/src/Tests/SearchMultilingualEntityTest.php
index 0370ee2180a4acbd4c092d557d051b4c27aa688c..ad2445f91c22d80e87a60dcdfecf5ffa83dfcbe5 100644
--- a/core/modules/search/src/Tests/SearchMultilingualEntityTest.php
+++ b/core/modules/search/src/Tests/SearchMultilingualEntityTest.php
@@ -59,7 +59,7 @@ protected function setUp() {
     // definition. The parent class has already created the article and page
     // content types.
     $field_storage = FieldStorageConfig::loadByName('node', 'body');
-    $field_storage->translatable = TRUE;
+    $field_storage->setTranslatable(TRUE);
     $field_storage->save();
 
     // Create a few page nodes with multilingual body values.
diff --git a/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php b/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
index cee9a0b7dcb34b69f27a590ad2668bba5e53be75..933f8dd8692baa14e37b2d59b9378c2883e25253 100644
--- a/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
+++ b/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
@@ -99,7 +99,7 @@ function testEntityFormLanguage() {
 
     // Make body translatable.
     $field_storage = FieldStorageConfig::loadByName('node', 'body');
-    $field_storage->translatable = TRUE;
+    $field_storage->setTranslatable(TRUE);
     $field_storage->save();
     $field_storage = FieldStorageConfig::loadByName('node', 'body');
     $this->assertTrue($field_storage->isTranslatable(), 'Field body is translatable.');
diff --git a/core/modules/system/src/Tests/Entity/FieldSqlStorageTest.php b/core/modules/system/src/Tests/Entity/FieldSqlStorageTest.php
index 8fdb484f3ee851f44f7da0a6961809f956427ae4..688daf203463ab33da049c7b28947144235e34bc 100644
--- a/core/modules/system/src/Tests/Entity/FieldSqlStorageTest.php
+++ b/core/modules/system/src/Tests/Entity/FieldSqlStorageTest.php
@@ -332,7 +332,7 @@ function testUpdateFieldSchemaWithData() {
     $entity->save();
 
     // Attempt to update the field in a way that would work without data.
-    $field_storage->settings['scale'] = 3;
+    $field_storage->setSetting('scale', 3);
     try {
       $field_storage->save();
       $this->fail(t('Cannot update field schema with data.'));
@@ -357,7 +357,7 @@ function testFieldUpdateFailure() {
 
     // Attempt to update the field in a way that would break the storage.
     $prior_field_storage = $field_storage;
-    $field_storage->settings['max_length'] = -1;
+    $field_storage->setSetting('max_length', -1);
     try {
       $field_storage->save();
       $this->fail(t('Update succeeded.'));
@@ -412,14 +412,14 @@ function testFieldUpdateIndexesWithData() {
     $entity->save();
 
     // Add an index.
-    $field_storage->indexes = array('value' => array(array('value', 255)));
+    $field_storage->setIndexes(['value' => [['value', 255]]]);
     $field_storage->save();
     foreach ($tables as $table) {
       $this->assertTrue(Database::getConnection()->schema()->indexExists($table, "{$field_name}_value"), t("Index on value created in @table", array('@table' => $table)));
     }
 
     // Add a different index, removing the existing custom one.
-    $field_storage->indexes = array('value_format' => array(array('value', 127), array('format', 127)));
+    $field_storage->setIndexes(['value_format' => [['value', 127], ['format', 127]]]);
     $field_storage->save();
     foreach ($tables as $table) {
       $this->assertTrue(Database::getConnection()->schema()->indexExists($table, "{$field_name}_value_format"), t("Index on value_format created in @table", array('@table' => $table)));
@@ -455,7 +455,7 @@ function testFieldSqlStorageForeignKeys() {
 
     // Update the field settings, it should update the foreign key definition too.
     $foreign_key_name = 'color';
-    $field_storage->settings['foreign_key_name'] = $foreign_key_name;
+    $field_storage->setSetting('foreign_key_name', $foreign_key_name);
     $field_storage->save();
     // Reload the field schema after the update.
     $schema = $field_storage->getSchema();
diff --git a/core/modules/taxonomy/src/Entity/Vocabulary.php b/core/modules/taxonomy/src/Entity/Vocabulary.php
index ae7b10f1e5d487339b3d701ee60a771af4228dd3..b8edfde693ba540b8e71103a9311f72843a6665a 100644
--- a/core/modules/taxonomy/src/Entity/Vocabulary.php
+++ b/core/modules/taxonomy/src/Entity/Vocabulary.php
@@ -137,12 +137,14 @@ public function postSave(EntityStorageInterface $storage, $update = TRUE) {
       foreach ($field_storages as $field_storage) {
         $update_storage = FALSE;
 
-        foreach ($field_storage->settings['allowed_values'] as &$value) {
+        $allowed_values = $field_storage->getSetting('allowed_values');
+        foreach ($allowed_values as &$value) {
           if ($value['vocabulary'] == $this->getOriginalId()) {
             $value['vocabulary'] = $this->id();
             $update_storage = TRUE;
           }
         }
+        $field_storage->setSetting('allowed_values', $allowed_values);
 
         if ($update_storage) {
           $field_storage->save();
@@ -186,14 +188,17 @@ public static function postDelete(EntityStorageInterface $storage, array $entiti
       $modified_storage = FALSE;
       // Term reference fields may reference terms from more than one
       // vocabulary.
-      foreach ($field_storage->settings['allowed_values'] as $key => $allowed_value) {
+      foreach ($field_storage->getSetting('allowed_values') as $key => $allowed_value) {
         if (isset($vocabularies[$allowed_value['vocabulary']])) {
-          unset($field_storage->settings['allowed_values'][$key]);
+          $allowed_values = $field_storage->getSetting('allowed_values');
+          unset($allowed_values[$key]);
+          $field_storage->setSetting('allowed_values', $allowed_values);
           $modified_storage = TRUE;
         }
       }
       if ($modified_storage) {
-        if (empty($field_storage->settings['allowed_values'])) {
+        $allowed_values = $field_storage->getSetting('allowed_values');
+        if (empty($allowed_values)) {
           $field_storage->delete();
         }
         else {
diff --git a/core/modules/taxonomy/src/Tests/TermFieldTest.php b/core/modules/taxonomy/src/Tests/TermFieldTest.php
index e3f0abd77d6abc878f0a6dd9d6dd86723d552c8c..d41a0832aba9e1135ee7ca91491de2465a46d7de 100644
--- a/core/modules/taxonomy/src/Tests/TermFieldTest.php
+++ b/core/modules/taxonomy/src/Tests/TermFieldTest.php
@@ -161,7 +161,7 @@ function testTaxonomyTermFieldSettingsAutocompleteWidget() {
   function testTaxonomyTermFieldChangeMachineName() {
     // Add several entries in the 'allowed_values' setting, to make sure that
     // they all get updated.
-    $this->fieldStorage->settings['allowed_values'] = array(
+    $this->fieldStorage->setSetting('allowed_values', [
       array(
         'vocabulary' => $this->vocabulary->id(),
         'parent' => '0',
@@ -174,7 +174,7 @@ function testTaxonomyTermFieldChangeMachineName() {
         'vocabulary' => 'foo',
         'parent' => '0',
       ),
-    );
+    ]);
     $this->fieldStorage->save();
     // Change the machine name.
     $new_name = Unicode::strtolower($this->randomMachineName());
diff --git a/core/modules/user/src/Tests/UserRegistrationTest.php b/core/modules/user/src/Tests/UserRegistrationTest.php
index 221667f9643d40067b20eeabaca3c994d8279ab9..f1eb6379d96473a353cfbc9ce6f79ac22491c48d 100644
--- a/core/modules/user/src/Tests/UserRegistrationTest.php
+++ b/core/modules/user/src/Tests/UserRegistrationTest.php
@@ -247,7 +247,7 @@ function testRegistrationWithUserFields() {
     $this->assertEqual($new_user->test_user_field->value, $value, 'The field value was correclty saved.');
 
     // Check that the 'add more' button works.
-    $field_storage->cardinality = FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED;
+    $field_storage->setCardinality(FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED);
     $field_storage->save();
     foreach (array('js', 'nojs') as $js) {
       $this->drupalGet('user/register');
diff --git a/core/modules/views/views.api.php b/core/modules/views/views.api.php
index 9f2813b395bb10ca53911f3dbe76f546d63f8dad..2001c83b010cdfdc03629c96261cf8264640bce9 100644
--- a/core/modules/views/views.api.php
+++ b/core/modules/views/views.api.php
@@ -500,7 +500,7 @@ function hook_field_views_data(\Drupal\field\FieldStorageConfigInterface $field_
  * @see hook_field_views_data_views_data_alter()
  */
 function hook_field_views_data_alter(array &$data, \Drupal\field\FieldStorageConfigInterface $field_storage) {
-  $entity_type_id = $field_storage->entity_type;
+  $entity_type_id = $field_storage->getTargetEntityTypeId();
   $field_name = $field_storage->getName();
   $entity_type = \Drupal::entityManager()->getDefinition($entity_type_id);
   $pseudo_field_name = 'reverse_' . $field_name . '_' . $entity_type_id;
diff --git a/core/modules/views/views.views.inc b/core/modules/views/views.views.inc
index 1e91727b642b98a1c525c1787f929d02896806c5..203764501267442073dfb97a6d854a40b20c063e 100644
--- a/core/modules/views/views.views.inc
+++ b/core/modules/views/views.views.inc
@@ -176,9 +176,10 @@ function views_views_data() {
 
   $entity_manager = \Drupal::entityManager();
   if ($entity_manager->hasDefinition('field_storage_config')) {
+    /** @var \Drupal\field\FieldStorageConfigInterface $field_storage */
     foreach ($entity_manager->getStorage('field_storage_config')->loadMultiple() as $field_storage) {
       if (_views_field_get_entity_type_storage($field_storage)) {
-        $result = (array) $module_handler->invoke($field_storage->module, 'field_views_data', array($field_storage));
+        $result = (array) $module_handler->invoke($field_storage->getTypeProvider(), 'field_views_data', array($field_storage));
         if (empty($result)) {
           $result = views_field_default_views_data($field_storage);
         }
@@ -207,9 +208,10 @@ function views_views_data_alter(&$data) {
   if (!$entity_manager->hasDefinition('field_storage_config')) {
     return;
   }
+  /** @var \Drupal\field\FieldStorageConfigInterface $field_storage */
   foreach ($entity_manager->getStorage('field_storage_config')->loadMultiple() as $field_storage) {
     if (_views_field_get_entity_type_storage($field_storage)) {
-      $function = $field_storage->module . '_field_views_data_views_data_alter';
+      $function = $field_storage->getTypeProvider() . '_field_views_data_views_data_alter';
       if (function_exists($function)) {
         $function($data, $field_storage);
       }