diff --git a/core/lib/Drupal/Core/Entity/ContentEntityBase.php b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
index 3564f1f..7ec4bb1 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
@@ -602,7 +602,7 @@ public function onChange($name) {
   /**
    * {@inheritdoc}
    *
-   * @return \Drupal\Core\Entity\EntityInterface
+   * @return \Drupal\Core\Entity\ContentEntityInterface
    */
   public function getTranslation($langcode) {
     // Ensure we always use the default language code when dealing with the
diff --git a/core/lib/Drupal/Core/Field/ConfigEntityReferenceItemBase.php b/core/lib/Drupal/Core/Field/ConfigEntityReferenceItemBase.php
index 8169e27..42f84bf 100644
--- a/core/lib/Drupal/Core/Field/ConfigEntityReferenceItemBase.php
+++ b/core/lib/Drupal/Core/Field/ConfigEntityReferenceItemBase.php
@@ -23,47 +23,23 @@
 class ConfigEntityReferenceItemBase extends EntityReferenceItem implements ConfigFieldItemInterface {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see ConfigurableEntityReferenceItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    $settings = $this->definition->getSettings();
-    $target_type = $settings['target_type'];
-
-    // Definitions vary by entity type and bundle, so key them accordingly.
-    $key = $target_type . ':';
-    $key .= isset($settings['target_bundle']) ? $settings['target_bundle'] : '';
-
-    if (!isset(static::$propertyDefinitions[$key])) {
-      // Call the parent to define the target_id and entity properties.
-      parent::getPropertyDefinitions();
-
-      // Only add the revision ID property if the target entity type supports
-      // revisions.
-      $target_type_info = \Drupal::entityManager()->getDefinition($target_type);
-      if (!empty($target_type_info['entity_keys']['revision']) && !empty($target_type_info['revision_table'])) {
-        static::$propertyDefinitions[$key]['revision_id'] = DataDefinition::create('integer')
-          ->setLabel(t('Revision ID'))
-          ->setConstraints(array('Range' => array('min' => 0)));
-      }
-
-      static::$propertyDefinitions[$key]['label'] = DataDefinition::create('string')
-        ->setLabel(t('Label (auto-create)'))
-        ->setComputed(TRUE);
-
-      static::$propertyDefinitions[$key]['access'] = DataDefinition::create('boolean')
-        ->setLabel(t('Access'))
-        ->setComputed(TRUE);
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    // Call the parent to define the target_id and entity properties.
+    $property_definitions = parent::getPropertyDefinitions($field_definition);
+
+    // Only add the revision ID property if the target entity type supports
+    // revisions.
+    $target_type = $field_definition->getSetting('target_type');
+    $target_type_info = \Drupal::entityManager()->getDefinition($target_type);
+    if (!empty($target_type_info['entity_keys']['revision']) && !empty($target_type_info['revision_table'])) {
+      $property_definitions['revision_id'] = DataDefinition::create('integer')
+        ->setLabel(t('Revision ID'))
+        ->setConstraints(array('Range' => array('min' => 0)));
     }
-    return static::$propertyDefinitions[$key];
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/FieldItemInterface.php b/core/lib/Drupal/Core/Field/FieldItemInterface.php
index b9154db..276167f 100644
--- a/core/lib/Drupal/Core/Field/FieldItemInterface.php
+++ b/core/lib/Drupal/Core/Field/FieldItemInterface.php
@@ -24,6 +24,18 @@
 interface FieldItemInterface extends ComplexDataInterface {
 
   /**
+   * Gets an array of property definitions of contained properties.
+   *
+   * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
+   *   The field definition.
+   *
+   * @return \Drupal\Core\TypedData\DataDefinitionInterface[]
+   *   An array of property definitions of contained properties, keyed by
+   *   property name.
+   */
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition);
+
+  /**
    * Returns the schema for the field.
    *
    * This method is static because the field schema information is needed on
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php
index 1d9884f..3816f95 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php
@@ -24,23 +24,13 @@
 class BooleanItem extends FieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see BooleanItem::getPropertyDefinitions()
-   *
-   * @var array
+   * {@inheritdoc}
    */
-  static $propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('boolean')
+      ->setLabel(t('Boolean value'));
 
-  /**
-   * Implements \Drupal\Core\TypedData\ComplexDataInterface::getPropertyDefinitions().
-   */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('boolean')
-        ->setLabel(t('Boolean value'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/DateItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/DateItem.php
index c1276dd..1c3cb3c 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/DateItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/DateItem.php
@@ -23,26 +23,15 @@
 class DateItem extends FieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see DateItem::getPropertyDefinitions()
-   *
-   * @var array
+   * {@inheritdoc}
    */
-  static $propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = array(
+      'type' => 'date',
+      'label' => t('Date value'),
+    );
 
-  /**
-   * Implements \Drupal\Core\TypedData\ComplexDataInterface::getPropertyDefinitions().
-   */
-  public function getPropertyDefinitions() {
-
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = array(
-        'type' => 'date',
-        'label' => t('Date value'),
-      );
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EmailItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EmailItem.php
index aee1a4a..5becfad 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EmailItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EmailItem.php
@@ -24,24 +24,13 @@
 class EmailItem extends FieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see EmailItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
-   * Implements ComplexDataInterface::getPropertyDefinitions().
+   * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('email')
+      ->setLabel(t('E-mail value'));
 
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('email')
-        ->setLabel(t('E-mail value'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
index 0c8c8a2..c0122d3 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
@@ -31,56 +31,42 @@
 class EntityReferenceItem extends FieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see EntityReferenceItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
-   * Implements \Drupal\Core\TypedData\ComplexDataInterface::getPropertyDefinitions().
+   * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    $settings = $this->definition->getSettings();
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $settings = $field_definition->getSettings();
     $target_type = $settings['target_type'];
 
-    // Definitions vary by entity type and bundle, so key them accordingly.
-    $key = $target_type . ':';
-    $key .= isset($settings['target_bundle']) ? $settings['target_bundle'] : '';
-
-    if (!isset(static::$propertyDefinitions[$key])) {
-      $target_type_info = \Drupal::entityManager()->getDefinition($target_type);
-      if (is_subclass_of($target_type_info['class'], '\Drupal\Core\Entity\ContentEntityInterface')) {
-        // @todo: Lookup the entity type's ID data type and use it here.
-        // https://drupal.org/node/2107249
-        static::$propertyDefinitions[$key]['target_id'] = DataDefinition::create('integer')
-          ->setLabel(t('Entity ID'))
-          ->setConstraints(array(
-            'Range' => array('min' => 0),
-          ));
-      }
-      else {
-        static::$propertyDefinitions[$key]['target_id'] = DataDefinition::create('string')
-          ->setLabel(t('Entity ID'));
-      }
-
-      static::$propertyDefinitions[$key]['entity'] = DataDefinition::create('entity_reference')
-        ->setLabel(t('Entity'))
-        ->setDescription(t('The referenced entity'))
-        // The entity object is computed out of the entity ID.
-        ->setComputed(TRUE)
-        ->setReadOnly(FALSE)
+    $target_type_info = \Drupal::entityManager()->getDefinition($target_type);
+    if (is_subclass_of($target_type_info['class'], '\Drupal\Core\Entity\ContentEntityInterface')) {
+      // @todo: Lookup the entity type's ID data type and use it here.
+      // https://drupal.org/node/2107249
+      $property_definitions['target_id'] = DataDefinition::create('integer')
+        ->setLabel(t('Entity ID'))
         ->setConstraints(array(
-          'EntityType' => $settings['target_type'],
+          'Range' => array('min' => 0),
         ));
+    }
+    else {
+      $property_definitions['target_id'] = DataDefinition::create('string')
+        ->setLabel(t('Entity ID'));
+    }
 
-      if (isset($settings['target_bundle'])) {
-        static::$propertyDefinitions[$key]['entity']->addConstraint('Bundle', $settings['target_bundle']);
-      }
+    $property_definitions['entity'] = DataDefinition::create('entity_reference')
+      ->setLabel(t('Entity'))
+      ->setDescription(t('The referenced entity'))
+      // The entity object is computed out of the entity ID.
+      ->setComputed(TRUE)
+      ->setReadOnly(FALSE)
+      ->setConstraints(array(
+        'EntityType' => $settings['target_type'],
+      ));
+
+    if (isset($settings['target_bundle'])) {
+      $property_definitions['entity']->addConstraint('Bundle', $settings['target_bundle']);
     }
-    return static::$propertyDefinitions[$key];
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/FloatItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/FloatItem.php
index 045af1c..e33ee85 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/FloatItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/FloatItem.php
@@ -24,24 +24,13 @@
 class FloatItem extends FieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see IntegerItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
-   * Implements \Drupal\Core\TypedData\ComplexDataInterface::getPropertyDefinitions().
+   * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('float')
+      ->setLabel(t('Float value'));
 
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('float')
-        ->setLabel(t('Float value'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/IntegerItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/IntegerItem.php
index ec49cdb..e6ea56c 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/IntegerItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/IntegerItem.php
@@ -24,24 +24,13 @@
 class IntegerItem extends FieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see IntegerItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('integer')
+      ->setLabel(t('Integer value'));
 
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('integer')
-        ->setLabel(t('Integer value'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php
index 3bae65b..311d3b4 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php
@@ -30,30 +30,20 @@
 class LanguageItem extends FieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see LanguageItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
-   * Implements \Drupal\Core\TypedData\ComplexDataInterface::getPropertyDefinitions().
+   * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('string')
-        ->setLabel(t('Language code'));
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('string')
+      ->setLabel(t('Language code'));
 
-      static::$propertyDefinitions['language'] = DataDefinition::create('language_reference')
-        ->setLabel(t('Language object'))
-        ->setDescription(t('The referenced language'))
+    $property_definitions['language'] = DataDefinition::create('language_reference')
+      ->setLabel(t('Language object'))
+      ->setDescription(t('The referenced language'))
       // The language object is retrieved via the language code.
-        ->setComputed(TRUE)
-        ->setReadOnly(FALSE);
-    }
-    return static::$propertyDefinitions;
+      ->setComputed(TRUE)
+      ->setReadOnly(FALSE);
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
index ce78a40..ec1de23 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
@@ -27,24 +27,13 @@
 class StringItem extends FieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see StringItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('string')
+      ->setLabel(t('Text value'));
 
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('string')
-        ->setLabel(t('Text value'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php
index 4cad163..dcdefcc 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php
@@ -24,23 +24,13 @@
 class UriItem extends FieldItemBase {
 
   /**
-   * Field definitions of the contained properties.
-   *
-   * @see self::getPropertyDefinitions()
-   *
-   * @var array
+   * {@inheritdoc}
    */
-  static $propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('uri')
+      ->setLabel(t('URI value'));
 
-  /**
-   * Implements ComplexDataInterface::getPropertyDefinitions().
-   */
-  public function getPropertyDefinitions() {
-    if (!isset(self::$propertyDefinitions)) {
-      self::$propertyDefinitions['value'] = DataDefinition::create('uri')
-        ->setLabel(t('URI value'));
-    }
-    return self::$propertyDefinitions;
+    return $property_definitions;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/TypedData/ComplexDataDefinitionBase.php b/core/lib/Drupal/Core/TypedData/ComplexDataDefinitionBase.php
new file mode 100644
index 0000000..68d7f6d
--- /dev/null
+++ b/core/lib/Drupal/Core/TypedData/ComplexDataDefinitionBase.php
@@ -0,0 +1,44 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\TypedData\ComplexDataDefinitionBase.
+ */
+
+namespace Drupal\Core\TypedData;
+
+/**
+ * Base class for complex data definitions.
+ */
+abstract class ComplexDataDefinitionBase implements ComplexDataDefinitionInterface {
+
+  /**
+   * An array of data definitions.
+   *
+   * @var \Drupal\Core\TypedData\DataDefinitionInterface[]
+   *
+   * @see ComplexDataDefinitionBase::getPropertyDefinitions()
+   */
+  protected $propertyDefinitions;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPropertyDefinition($name) {
+    if (!isset($this->propertyDefinitions)) {
+      $this->getPropertyDefinitions();
+    }
+    if (isset($this->propertyDefinitions[$name])) {
+      return $this->propertyDefinitions[$name];
+    }
+    else {
+      return NULL;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  abstract public function getPropertyDefinitions();
+
+}
diff --git a/core/lib/Drupal/Core/TypedData/ComplexDataDefinitionInterface.php b/core/lib/Drupal/Core/TypedData/ComplexDataDefinitionInterface.php
new file mode 100644
index 0000000..9c38513
--- /dev/null
+++ b/core/lib/Drupal/Core/TypedData/ComplexDataDefinitionInterface.php
@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\TypedData\ComplexDataDefinitionInterface.
+ */
+
+namespace Drupal\Core\TypedData;
+
+/**
+ * Interface for complex data definitions.
+ *
+ */
+interface ComplexDataDefinitionInterface extends DataDefinitionInterface  {
+
+  /**
+   * Gets the definition of a contained property.
+   *
+   * @param string $name
+   *   The name of property.
+   *
+   * @return \Drupal\Core\TypedData\DataDefinitionInterface|null
+   *   The definition of the property or NULL if the property does not exist.
+   */
+  public function getPropertyDefinition($name);
+
+  /**
+   * Gets an array of property definitions of contained properties.
+   *
+   * @return \Drupal\Core\TypedData\DataDefinitionInterface[]
+   *   An array of property definitions of contained properties, keyed by
+   *   property name.
+   */
+  public function getPropertyDefinitions();
+
+}
diff --git a/core/lib/Drupal/Core/TypedData/ComplexDataInterface.php b/core/lib/Drupal/Core/TypedData/ComplexDataInterface.php
index 438ea6e..76886be 100644
--- a/core/lib/Drupal/Core/TypedData/ComplexDataInterface.php
+++ b/core/lib/Drupal/Core/TypedData/ComplexDataInterface.php
@@ -91,25 +91,25 @@ public function getPropertyValues();
    */
   public function setPropertyValues($values);
 
-  /**
-   * Gets the definition of a contained property.
-   *
-   * @param string $name
-   *   The name of property.
-   *
-   * @return array|FALSE
-   *   The definition of the property or FALSE if the property does not exist.
-   */
-  public function getPropertyDefinition($name);
-
-  /**
-   * Gets an array of property definitions of contained properties.
-   *
-   * @return \Drupal\Core\TypedData\DataDefinitionInterface[]
-   *   An array of property definitions of contained properties, keyed by
-   *   property name.
-   */
-  public function getPropertyDefinitions();
+//  /**
+//   * Gets the definition of a contained property.
+//   *
+//   * @param string $name
+//   *   The name of property.
+//   *
+//   * @return array|FALSE
+//   *   The definition of the property or FALSE if the property does not exist.
+//   */
+//  public function getPropertyDefinition($name);
+//
+//  /**
+//   * Gets an array of property definitions of contained properties.
+//   *
+//   * @return \Drupal\Core\TypedData\DataDefinitionInterface[]
+//   *   An array of property definitions of contained properties, keyed by
+//   *   property name.
+//   */
+//  public function getPropertyDefinitions();
 
   /**
    * Determines whether the data structure is empty.
diff --git a/core/lib/Drupal/Core/TypedData/Plugin/DataType/Map.php b/core/lib/Drupal/Core/TypedData/Plugin/DataType/Map.php
index f3acbd3..133e43d 100644
--- a/core/lib/Drupal/Core/TypedData/Plugin/DataType/Map.php
+++ b/core/lib/Drupal/Core/TypedData/Plugin/DataType/Map.php
@@ -38,22 +38,22 @@ class Map extends TypedData implements \IteratorAggregate, ComplexDataInterface
   protected $values = array();
 
   /**
-   * The array of properties, each implementing the TypedDataInterface.
+   * The array of properties.
    *
-   * @var array
+   * @var \Drupal\Core\TypedData\TypedDataInterface[]
    */
   protected $properties = array();
 
   /**
    * Implements \Drupal\Core\TypedData\ComplexDataInterface::getPropertyDefinitions().
    */
-  public function getPropertyDefinitions() {
-    $definitions = array();
-    foreach ($this->values as $name => $value) {
-      $definitions[$name] = DataDefinition::create('any');
-    }
-    return $definitions;
-  }
+//  public function getPropertyDefinitions() {
+//    $definitions = array();
+//    foreach ($this->values as $name => $value) {
+//      $definitions[$name] = DataDefinition::create('any');
+//    }
+//    return $definitions;
+//  }
 
   /**
    * Overrides \Drupal\Core\TypedData\TypedData::getValue().
@@ -186,15 +186,15 @@ public function getIterator() {
   /**
    * Implements \Drupal\Core\TypedData\ComplexDataInterface::getPropertyDefinition().
    */
-  public function getPropertyDefinition($name) {
-    $definitions = $this->getPropertyDefinitions();
-    if (isset($definitions[$name])) {
-      return $definitions[$name];
-    }
-    else {
-      return FALSE;
-    }
-  }
+//  public function getPropertyDefinition($name) {
+//    $definitions = $this->getPropertyDefinitions();
+//    if (isset($definitions[$name])) {
+//      return $definitions[$name];
+//    }
+//    else {
+//      return FALSE;
+//    }
+//  }
 
   /**
    * Implements \Drupal\Core\TypedData\ComplexDataInterface::isEmpty().
diff --git a/core/modules/comment/lib/Drupal/comment/CommentFieldName.php b/core/modules/comment/lib/Drupal/comment/CommentFieldName.php
index 7912fcc..9cb56b5 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentFieldName.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentFieldName.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\comment;
 
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\Plugin\Field\FieldType\StringItem;
 use Drupal\Core\TypedData\DataDefinition;
 
@@ -16,26 +17,15 @@
 class CommentFieldName extends StringItem {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see self::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('string')
+      ->setLabel(t('String value'))
+      ->setClass('\Drupal\comment\CommentFieldNameValue')
+      ->setComputed(TRUE);
 
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('string')
-        ->setLabel(t('String value'))
-        ->setClass('\Drupal\comment\CommentFieldNameValue')
-        ->setComputed(TRUE);
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
 }
diff --git a/core/modules/comment/lib/Drupal/comment/Plugin/Field/FieldType/CommentItem.php b/core/modules/comment/lib/Drupal/comment/Plugin/Field/FieldType/CommentItem.php
index 3145e8f..29a2a55 100644
--- a/core/modules/comment/lib/Drupal/comment/Plugin/Field/FieldType/CommentItem.php
+++ b/core/modules/comment/lib/Drupal/comment/Plugin/Field/FieldType/CommentItem.php
@@ -33,39 +33,31 @@
 class CommentItem extends ConfigFieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @var array
-   */
-  public static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['status'] = DataDefinition::create('integer')
-        ->setLabel(t('Comment status value'));
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['status'] = DataDefinition::create('integer')
+      ->setLabel(t('Comment status value'));
 
-      static::$propertyDefinitions['cid'] = DataDefinition::create('integer')
-        ->setLabel(t('Last comment ID'));
+    $property_definitions['cid'] = DataDefinition::create('integer')
+      ->setLabel(t('Last comment ID'));
 
-      static::$propertyDefinitions['last_comment_timestamp'] = DataDefinition::create('integer')
-        ->setLabel(t('Last comment timestamp'))
-        ->setDescription(t('The time that the last comment was created.'));
+    $property_definitions['last_comment_timestamp'] = DataDefinition::create('integer')
+      ->setLabel(t('Last comment timestamp'))
+      ->setDescription(t('The time that the last comment was created.'));
 
-      static::$propertyDefinitions['last_comment_name'] = DataDefinition::create('string')
-        ->setLabel(t('Last comment name'))
-        ->setDescription(t('The name of the user posting the last comment.'));
+    $property_definitions['last_comment_name'] = DataDefinition::create('string')
+      ->setLabel(t('Last comment name'))
+      ->setDescription(t('The name of the user posting the last comment.'));
 
-      static::$propertyDefinitions['last_comment_uid'] = DataDefinition::create('integer')
-        ->setLabel(t('Last comment user ID'));
+    $property_definitions['last_comment_uid'] = DataDefinition::create('integer')
+      ->setLabel(t('Last comment user ID'));
 
-      static::$propertyDefinitions['comment_count'] = DataDefinition::create('integer')
-        ->setLabel(t('Number of comments'))
-        ->setDescription(t('The number of comments.'));
-    }
-    return static::$propertyDefinitions;
+    $property_definitions['comment_count'] = DataDefinition::create('integer')
+      ->setLabel(t('Number of comments'))
+      ->setDescription(t('The number of comments.'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldType/DateTimeItem.php b/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldType/DateTimeItem.php
index ca7e56c..43029d2 100644
--- a/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldType/DateTimeItem.php
+++ b/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldType/DateTimeItem.php
@@ -32,29 +32,20 @@
 class DateTimeItem extends ConfigFieldItemBase implements PrepareCacheInterface {
 
   /**
-   * Field definitions of the contained properties.
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('datetime_iso8601')
-        ->setLabel(t('Date value'));
-
-      static::$propertyDefinitions['date'] = DataDefinition::create('datetime_computed')
-        ->setLabel(t('Computed date'))
-        ->setDescription(t('The computed DateTime object.'))
-        ->setComputed(TRUE)
-        ->setClass('\Drupal\datetime\DateTimeComputed')
-        ->setSetting('date source', 'value');
-    }
-
-    return static::$propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('datetime_iso8601')
+      ->setLabel(t('Date value'));
+
+    $property_definitions['date'] = DataDefinition::create('datetime_computed')
+      ->setLabel(t('Computed date'))
+      ->setDescription(t('The computed DateTime object.'))
+      ->setComputed(TRUE)
+      ->setClass('\Drupal\datetime\DateTimeComputed')
+      ->setSetting('date source', 'value');
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/HiddenTestItem.php b/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/HiddenTestItem.php
index e7b1cb3..eb90d2c 100644
--- a/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/HiddenTestItem.php
+++ b/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/HiddenTestItem.php
@@ -7,10 +7,8 @@
 
 namespace Drupal\field_test\Plugin\Field\FieldType;
 
-use Drupal\Core\Entity\Annotation\FieldType;
-use Drupal\Core\Annotation\Translation;
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\TypedData\DataDefinition;
-use Drupal\field_test\Plugin\Field\FieldType\TestItem;
 
 /**
  * Defines the 'hidden_test' entity field item.
@@ -27,23 +25,13 @@
 class HiddenTestItem extends TestItem {
 
   /**
-   * Property definitions of the contained properties.
-   *
-   * @see TestItem::getPropertyDefinitions()
-   *
-   * @var array
+   * {@inheritdoc}
    */
-  static $propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('integer')
+      ->setLabel(t('Test integer value'));
 
-  /**
-   * Implements \Drupal\Core\TypedData\ComplexDataInterface::getPropertyDefinitions().
-   */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('integer')
-        ->setLabel(t('Test integer value'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
 }
diff --git a/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/ShapeItem.php b/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/ShapeItem.php
index 15d05cd..68918f5 100644
--- a/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/ShapeItem.php
+++ b/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/ShapeItem.php
@@ -28,26 +28,16 @@
 class ShapeItem extends ConfigFieldItemBase {
 
   /**
-   * Property definitions of the contained properties.
-   *
-   * @see ShapeItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['shape'] = DataDefinition::create('string')
-        ->setLabel(t('Shape'));
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['shape'] = DataDefinition::create('string')
+      ->setLabel(t('Shape'));
 
-      static::$propertyDefinitions['color'] = DataDefinition::create('string')
-        ->setLabel(t('Color'));
-    }
-    return static::$propertyDefinitions;
+    $property_definitions['color'] = DataDefinition::create('string')
+      ->setLabel(t('Color'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/TestItem.php b/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/TestItem.php
index f8cd226..9dc1fe8 100644
--- a/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/TestItem.php
+++ b/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/Field/FieldType/TestItem.php
@@ -35,23 +35,13 @@
 class TestItem extends ConfigFieldItemBase implements PrepareCacheInterface {
 
   /**
-   * Property definitions of the contained properties.
-   *
-   * @see TestItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('integer')
-        ->setLabel(t('Test integer value'));
-    }
-    return static::$propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('integer')
+      ->setLabel(t('Test integer value'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/file/lib/Drupal/file/Plugin/Field/FieldType/FileItem.php b/core/modules/file/lib/Drupal/file/Plugin/Field/FieldType/FileItem.php
index 9bb9dd0..1063672 100644
--- a/core/modules/file/lib/Drupal/file/Plugin/Field/FieldType/FileItem.php
+++ b/core/modules/file/lib/Drupal/file/Plugin/Field/FieldType/FileItem.php
@@ -38,15 +38,6 @@
 class FileItem extends EntityReferenceItem implements ConfigFieldItemInterface {
 
   /**
-   * Property definitions of the contained properties.
-   *
-   * @see FileItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
   public static function schema(FieldDefinitionInterface $field_definition) {
@@ -87,19 +78,19 @@ public static function schema(FieldDefinitionInterface $field_definition) {
   /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    $this->definition->setSetting('target_type', 'file');
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    // @todo Setting this here is weird, move it to the annotation.
+    $field_definition->setSetting('target_type', 'file');
 
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions = parent::getPropertyDefinitions();
+    $property_definitions = parent::getPropertyDefinitions($field_definition);
 
-      static::$propertyDefinitions['display'] = DataDefinition::create('boolean')
-        ->setLabel(t('Flag to control whether this file should be displayed when viewing content'));
+    $property_definitions['display'] = DataDefinition::create('boolean')
+      ->setLabel(t('Flag to control whether this file should be displayed when viewing content'));
 
-      static::$propertyDefinitions['description'] = DataDefinition::create('string')
-        ->setLabel(t('A description of the file'));
-    }
-    return static::$propertyDefinitions;
+    $property_definitions['description'] = DataDefinition::create('string')
+      ->setLabel(t('A description of the file'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/image/lib/Drupal/image/Plugin/Field/FieldType/ImageItem.php b/core/modules/image/lib/Drupal/image/Plugin/Field/FieldType/ImageItem.php
index 1cface2..9c14b3e 100644
--- a/core/modules/image/lib/Drupal/image/Plugin/Field/FieldType/ImageItem.php
+++ b/core/modules/image/lib/Drupal/image/Plugin/Field/FieldType/ImageItem.php
@@ -117,25 +117,25 @@ public static function schema(FieldDefinitionInterface $field_definition) {
   /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    $this->definition->setSetting('target_type', 'file');
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    // @todo Setting this here is weird, move it to the annotation.
+    $field_definition->setSetting('target_type', 'file');
 
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions = parent::getPropertyDefinitions();
+    $property_definitions = parent::getPropertyDefinitions($field_definition);
 
-      static::$propertyDefinitions['alt'] = DataDefinition::create('string')
-        ->setLabel(t("Alternative image text, for the image's 'alt' attribute."));
+    $property_definitions['alt'] = DataDefinition::create('string')
+      ->setLabel(t("Alternative image text, for the image's 'alt' attribute."));
 
-      static::$propertyDefinitions['title'] = DataDefinition::create('string')
-        ->setLabel(t("Image title text, for the image's 'title' attribute."));
+    $property_definitions['title'] = DataDefinition::create('string')
+      ->setLabel(t("Image title text, for the image's 'title' attribute."));
 
-      static::$propertyDefinitions['width'] = DataDefinition::create('integer')
-        ->setLabel(t('The width of the image in pixels.'));
+    $property_definitions['width'] = DataDefinition::create('integer')
+      ->setLabel(t('The width of the image in pixels.'));
 
-      static::$propertyDefinitions['height'] = DataDefinition::create('integer')
-        ->setLabel(t('The height of the image in pixels.'));
-    }
-    return static::$propertyDefinitions;
+    $property_definitions['height'] = DataDefinition::create('integer')
+      ->setLabel(t('The height of the image in pixels.'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/link/lib/Drupal/link/Plugin/Field/FieldType/LinkItem.php b/core/modules/link/lib/Drupal/link/Plugin/Field/FieldType/LinkItem.php
index 1102aec..71cf389 100644
--- a/core/modules/link/lib/Drupal/link/Plugin/Field/FieldType/LinkItem.php
+++ b/core/modules/link/lib/Drupal/link/Plugin/Field/FieldType/LinkItem.php
@@ -28,27 +28,19 @@
 class LinkItem extends ConfigFieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['url'] = DataDefinition::create('uri')
-        ->setLabel(t('URL'));
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['url'] = DataDefinition::create('uri')
+      ->setLabel(t('URL'));
+
+    $property_definitions['title'] = DataDefinition::create('string')
+      ->setLabel(t('Link text'));
 
-      static::$propertyDefinitions['title'] = DataDefinition::create('string')
-        ->setLabel(t('Link text'));
+    $property_definitions['attributes'] = DataDefinition::create('map')
+      ->setLabel(t('Attributes'));
 
-      static::$propertyDefinitions['attributes'] = DataDefinition::create('map')
-        ->setLabel(t('Attributes'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/DecimalItem.php b/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/DecimalItem.php
index 58b52a2..379481e 100644
--- a/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/DecimalItem.php
+++ b/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/DecimalItem.php
@@ -37,12 +37,11 @@ class DecimalItem extends NumberItemBase {
   /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('string')
-        ->setLabel(t('Decimal value'));
-    }
-    return static::$propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('string')
+      ->setLabel(t('Decimal value'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/FloatItem.php b/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/FloatItem.php
index 5765147..9b87c86 100644
--- a/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/FloatItem.php
+++ b/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/FloatItem.php
@@ -32,12 +32,11 @@ class FloatItem extends NumberItemBase {
   /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('float')
-        ->setLabel(t('Float value'));
-    }
-    return static::$propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('float')
+      ->setLabel(t('Float value'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/IntegerItem.php b/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/IntegerItem.php
index 6c44d76..f28f62e 100644
--- a/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/IntegerItem.php
+++ b/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/IntegerItem.php
@@ -32,12 +32,11 @@ class IntegerItem extends NumberItemBase {
   /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('integer')
-        ->setLabel(t('Integer value'));
-    }
-    return static::$propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('integer')
+      ->setLabel(t('Integer value'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/NumberItemBase.php b/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/NumberItemBase.php
index 0f33b42..f2892bd 100644
--- a/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/NumberItemBase.php
+++ b/core/modules/number/lib/Drupal/number/Plugin/Field/FieldType/NumberItemBase.php
@@ -15,13 +15,6 @@
 abstract class NumberItemBase extends ConfigFieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
   public function instanceSettingsForm(array $form, array &$form_state) {
diff --git a/core/modules/options/lib/Drupal/options/Type/ListFloatItem.php b/core/modules/options/lib/Drupal/options/Type/ListFloatItem.php
index 6b18833..3224c20 100644
--- a/core/modules/options/lib/Drupal/options/Type/ListFloatItem.php
+++ b/core/modules/options/lib/Drupal/options/Type/ListFloatItem.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\options\Type;
 
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\Plugin\Field\FieldType\LegacyConfigFieldItem;
 use Drupal\Core\TypedData\DataDefinition;
 
@@ -16,23 +17,13 @@
 class ListFloatItem extends LegacyConfigFieldItem {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see FloatItem::getPropertyDefinitions()
-   *
-   * @var array
+   * {@inheritdoc}
    */
-  static $propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('float')
+      ->setLabel(t('Float value'));
 
-  /**
-   * Implements ComplexDataInterface::getPropertyDefinitions().
-   */
-  public function getPropertyDefinitions() {
-
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('float')
-        ->setLabel(t('Float value'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
+
 }
diff --git a/core/modules/options/lib/Drupal/options/Type/ListIntegerItem.php b/core/modules/options/lib/Drupal/options/Type/ListIntegerItem.php
index 72ed788..82f665b 100644
--- a/core/modules/options/lib/Drupal/options/Type/ListIntegerItem.php
+++ b/core/modules/options/lib/Drupal/options/Type/ListIntegerItem.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\options\Type;
 
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\Plugin\Field\FieldType\LegacyConfigFieldItem;
 use Drupal\Core\TypedData\DataDefinition;
 
@@ -16,23 +17,13 @@
 class ListIntegerItem extends LegacyConfigFieldItem {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see IntegerItem::getPropertyDefinitions()
-   *
-   * @var array
+   * {@inheritdoc}
    */
-  static $propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('integer')
+      ->setLabel(t('Integer value'));
 
-  /**
-   * Implements ComplexDataInterface::getPropertyDefinitions().
-   */
-  public function getPropertyDefinitions() {
-
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('integer')
-        ->setLabel(t('Integer value'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
+
 }
diff --git a/core/modules/options/lib/Drupal/options/Type/ListTextItem.php b/core/modules/options/lib/Drupal/options/Type/ListTextItem.php
index b66d355..fdbb250 100644
--- a/core/modules/options/lib/Drupal/options/Type/ListTextItem.php
+++ b/core/modules/options/lib/Drupal/options/Type/ListTextItem.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\options\Type;
 
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\Plugin\Field\FieldType\LegacyConfigFieldItem;
 use Drupal\Core\TypedData\DataDefinition;
 
@@ -16,24 +17,13 @@
 class ListTextItem extends LegacyConfigFieldItem {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see TextItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * Implements ComplexDataInterface::getPropertyDefinitions().
    */
-  public function getPropertyDefinitions() {
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('string')
+      ->setLabel(t('Text value'));
 
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('string')
-        ->setLabel(t('Text value'));
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
 }
diff --git a/core/modules/path/lib/Drupal/path/Plugin/Field/FieldType/PathItem.php b/core/modules/path/lib/Drupal/path/Plugin/Field/FieldType/PathItem.php
index 6d75cac..67b6843 100644
--- a/core/modules/path/lib/Drupal/path/Plugin/Field/FieldType/PathItem.php
+++ b/core/modules/path/lib/Drupal/path/Plugin/Field/FieldType/PathItem.php
@@ -24,26 +24,16 @@
 class PathItem extends FieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @see PathItem::getPropertyDefinitions()
-   *
-   * @var array
+   * {@inheritdoc}
    */
-  static $propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['alias'] = DataDefinition::create('string')
+      ->setLabel(t('Path alias'));
 
-  /**
-   * Implements \Drupal\Core\TypedData\ComplexDataInterface::getPropertyDefinitions().
-   */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['alias'] = DataDefinition::create('string')
-        ->setLabel(t('Path alias'));
-
-      static::$propertyDefinitions['pid'] = DataDefinition::create('string')
-        ->setLabel(t('Path id'));
-    }
-    return static::$propertyDefinitions;
+    $property_definitions['pid'] = DataDefinition::create('string')
+      ->setLabel(t('Path id'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Type/TaxonomyTermReferenceItem.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Type/TaxonomyTermReferenceItem.php
index ac24daf..e805954 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Type/TaxonomyTermReferenceItem.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Type/TaxonomyTermReferenceItem.php
@@ -8,6 +8,7 @@
 namespace Drupal\taxonomy\Type;
 
 use Drupal\Core\Field\ConfigEntityReferenceItemBase;
+use Drupal\Core\Field\FieldDefinitionInterface;
 
 /**
  * Defines the 'taxonomy_term_reference' entity field item.
@@ -15,20 +16,12 @@
 class TaxonomyTermReferenceItem extends ConfigEntityReferenceItemBase {
 
   /**
-   * Property definitions of the contained properties.
-   *
-   * @see TaxonomyTermReferenceItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    $this->definition->setSetting('target_type', 'taxonomy_term');
-    return parent::getPropertyDefinitions();
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    // @todo Setting this here is weird, move it to the annotation.
+    $field_definition->setSetting('target_type', 'taxonomy_term');
+    return parent::getPropertyDefinitions($field_definition);
   }
 
 }
diff --git a/core/modules/telephone/lib/Drupal/telephone/Plugin/Field/FieldType/TelephoneItem.php b/core/modules/telephone/lib/Drupal/telephone/Plugin/Field/FieldType/TelephoneItem.php
index e23d6fa..8688f2b 100644
--- a/core/modules/telephone/lib/Drupal/telephone/Plugin/Field/FieldType/TelephoneItem.php
+++ b/core/modules/telephone/lib/Drupal/telephone/Plugin/Field/FieldType/TelephoneItem.php
@@ -25,13 +25,6 @@
 class TelephoneItem extends ConfigFieldItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
   public static function schema(FieldDefinitionInterface $field_definition) {
@@ -49,12 +42,11 @@ public static function schema(FieldDefinitionInterface $field_definition) {
   /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('string')
-        ->setLabel(t('Telephone number'));
-    }
-    return static::$propertyDefinitions;
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('string')
+      ->setLabel(t('Telephone number'));
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/text/lib/Drupal/text/Plugin/Field/FieldType/TextItemBase.php b/core/modules/text/lib/Drupal/text/Plugin/Field/FieldType/TextItemBase.php
index 90d86c2..5ad9280 100644
--- a/core/modules/text/lib/Drupal/text/Plugin/Field/FieldType/TextItemBase.php
+++ b/core/modules/text/lib/Drupal/text/Plugin/Field/FieldType/TextItemBase.php
@@ -8,6 +8,7 @@
 namespace Drupal\text\Plugin\Field\FieldType;
 
 use Drupal\Core\Field\ConfigFieldItemBase;
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\PrepareCacheInterface;
 use Drupal\Core\TypedData\DataDefinition;
 
@@ -17,31 +18,23 @@
 abstract class TextItemBase extends ConfigFieldItemBase implements PrepareCacheInterface {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['value'] = DataDefinition::create('string')
-        ->setLabel(t('Text value'));
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions['value'] = DataDefinition::create('string')
+      ->setLabel(t('Text value'));
 
-      static::$propertyDefinitions['format'] = DataDefinition::create('filter_format')
-        ->setLabel(t('Text format'));
+    $property_definitions['format'] = DataDefinition::create('filter_format')
+      ->setLabel(t('Text format'));
 
-      static::$propertyDefinitions['processed'] = DataDefinition::create('string')
-        ->setLabel(t('Processed text'))
-        ->setDescription(t('The text value with the text format applied.'))
-        ->setComputed(TRUE)
-        ->setClass('\Drupal\text\TextProcessed')
-        ->setSetting('text source', 'value');
-    }
-    return static::$propertyDefinitions;
+    $property_definitions['processed'] = DataDefinition::create('string')
+      ->setLabel(t('Processed text'))
+      ->setDescription(t('The text value with the text format applied.'))
+      ->setComputed(TRUE)
+      ->setClass('\Drupal\text\TextProcessed')
+      ->setSetting('text source', 'value');
+
+    return $property_definitions;
   }
 
   /**
diff --git a/core/modules/text/lib/Drupal/text/Plugin/Field/FieldType/TextWithSummaryItem.php b/core/modules/text/lib/Drupal/text/Plugin/Field/FieldType/TextWithSummaryItem.php
index 36df950..f2c613f 100644
--- a/core/modules/text/lib/Drupal/text/Plugin/Field/FieldType/TextWithSummaryItem.php
+++ b/core/modules/text/lib/Drupal/text/Plugin/Field/FieldType/TextWithSummaryItem.php
@@ -28,30 +28,22 @@
 class TextWithSummaryItem extends TextItemBase {
 
   /**
-   * Definitions of the contained properties.
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
    * {@inheritdoc}
    */
-  public function getPropertyDefinitions() {
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions = parent::getPropertyDefinitions();
+  public static function getPropertyDefinitions(FieldDefinitionInterface $field_definition) {
+    $property_definitions = parent::getPropertyDefinitions($field_definition);
+
+    $property_definitions['summary'] = DataDefinition::create('string')
+      ->setLabel(t('Summary text value'));
 
-      static::$propertyDefinitions['summary'] = DataDefinition::create('string')
-        ->setLabel(t('Summary text value'));
+    $property_definitions['summary_processed'] = DataDefinition::create('string')
+      ->setLabel(t('Processed summary text'))
+      ->setDescription(t('The summary text value with the text format applied.'))
+      ->setComputed(TRUE)
+      ->setClass('\Drupal\text\TextProcessed')
+      ->setSetting('text source', 'summary');
 
-      static::$propertyDefinitions['summary_processed'] = DataDefinition::create('string')
-        ->setLabel(t('Processed summary text'))
-        ->setDescription(t('The summary text value with the text format applied.'))
-        ->setComputed(TRUE)
-        ->setClass('\Drupal\text\TextProcessed')
-        ->setSetting('text source', 'summary');
-    }
-    return static::$propertyDefinitions;
+    return $property_definitions;
   }
 
   /**