From be785f08a9a5b752ceeab3a7238689b1445cb01d Mon Sep 17 00:00:00 2001
From: thierrydallacroce <thierry.dallacroce@gmail.com>
Date: Fri, 7 Jun 2019 08:46:40 -0700
Subject: [PATCH] References and endpoints for dataset properties and dynamic
 API routing (#129)

---
 cypress/integration/home.spec.js              |   1 +
 modules/custom/dkan_api/dkan_api.routing.yml  |  60 +-
 modules/custom/dkan_api/dkan_api.services.yml |   7 -
 .../custom/dkan_api/src/Controller/Api.php    |  69 +-
 .../dkan_api/src/Controller/Dataset.php       |  10 +
 .../dkan_api/src/Routing/RouteProvider.php    |  93 ++
 .../src/Storage/DrupalNodeDataset.php         |  70 +-
 .../src/Storage/ThemeValueReferencer.php      | 241 -----
 .../Unit/Storage/DrupalNodeDatasetTest.php    |  10 +-
 .../src/Unit/Storage/OrganizationTest.php     |   2 +-
 .../Unit/Storage/ThemeValueReferencerTest.php | 518 -----------
 .../dkan_common/dkan_common.links.menu.yml    |   5 +
 .../dkan_common/dkan_common.routing.yml       |   6 +
 .../config/install/dkan_data.settings.yml     |   4 +
 .../custom/dkan_data/dkan_data.links.menu.yml |   5 +
 modules/custom/dkan_data/dkan_data.module     |  44 +-
 .../custom/dkan_data/dkan_data.routing.yml    |   8 +
 .../custom/dkan_data/dkan_data.services.yml   |   7 +
 .../src/Form/DkanDataSettingsForm.php         |  60 ++
 .../QueueWorker/OrphanReferenceProcessor.php} |  50 +-
 .../custom/dkan_data/src/ValueReferencer.php  | 405 +++++++++
 ...est.php => ConfigurationOverriderTest.php} |   0
 .../tests/src/Unit/ValueReferencerTest.php    | 827 ++++++++++++++++++
 modules/custom/dkan_harvest/src/Reverter.php  |   1 +
 .../src/Controller/ApiController.php          |   3 +
 .../src/Unit/Controller/ApiControllerTest.php |   1 +
 26 files changed, 1596 insertions(+), 911 deletions(-)
 create mode 100644 modules/custom/dkan_api/src/Routing/RouteProvider.php
 delete mode 100644 modules/custom/dkan_api/src/Storage/ThemeValueReferencer.php
 delete mode 100644 modules/custom/dkan_api/tests/src/Unit/Storage/ThemeValueReferencerTest.php
 create mode 100644 modules/custom/dkan_common/dkan_common.links.menu.yml
 create mode 100644 modules/custom/dkan_common/dkan_common.routing.yml
 create mode 100644 modules/custom/dkan_data/config/install/dkan_data.settings.yml
 create mode 100644 modules/custom/dkan_data/dkan_data.links.menu.yml
 create mode 100644 modules/custom/dkan_data/dkan_data.routing.yml
 create mode 100644 modules/custom/dkan_data/src/Form/DkanDataSettingsForm.php
 rename modules/custom/{dkan_api/src/Plugin/QueueWorker/OrphanThemeProcessor.php => dkan_data/src/Plugin/QueueWorker/OrphanReferenceProcessor.php} (56%)
 create mode 100644 modules/custom/dkan_data/src/ValueReferencer.php
 rename modules/custom/dkan_data/tests/src/Unit/{CofigurationOverriderTest.php => ConfigurationOverriderTest.php} (100%)
 create mode 100644 modules/custom/dkan_data/tests/src/Unit/ValueReferencerTest.php

diff --git a/cypress/integration/home.spec.js b/cypress/integration/home.spec.js
index b5e13e06b3..898bb7b520 100755
--- a/cypress/integration/home.spec.js
+++ b/cypress/integration/home.spec.js
@@ -12,6 +12,7 @@ context('Home', () => {
       'Public Safety',
       'Transportation'
     ]
+
     for (var key in topics) {
       var value = topics[key]
       var index = parseInt(key) + 1
diff --git a/modules/custom/dkan_api/dkan_api.routing.yml b/modules/custom/dkan_api/dkan_api.routing.yml
index 8228734bf0..9e8e4eaf31 100644
--- a/modules/custom/dkan_api/dkan_api.routing.yml
+++ b/modules/custom/dkan_api/dkan_api.routing.yml
@@ -1,57 +1,3 @@
-dkan_api.dataset_get_all:
-  path: '/api/v1/dataset'
-  methods: [GET]
-  defaults:
-    { _controller: '\Drupal\dkan_api\Controller\Dataset::getAll'}
-  requirements:
-    _access: 'TRUE'
-dkan_api.dataset_get:
-  path: '/api/v1/dataset/{uuid}'
-  methods: [GET]
-  defaults:
-    { _controller: '\Drupal\dkan_api\Controller\Dataset::get'}
-  requirements:
-    _access: 'TRUE'
-dkan_api.dataset_post:
-  path: '/api/v1/dataset'
-  methods: [POST]
-  defaults:
-    { _controller: '\Drupal\dkan_api\Controller\Dataset::post'}
-  options:
-    _auth: [ 'basic_auth' ]
-  requirements:
-    _permission: 'post put delete datasets through the api'
-dkan_api.dataset_put:
-  path: '/api/v1/dataset/{uuid}'
-  methods: [PUT]
-  defaults:
-    { _controller: '\Drupal\dkan_api\Controller\Dataset::put'}
-  options:
-    _auth: [ 'basic_auth' ]
-  requirements:
-    _permission: 'post put delete datasets through the api'
-dkan_api.dataset_patch:
-  path: '/api/v1/dataset/{uuid}'
-  methods: [PATCH]
-  defaults:
-    { _controller: '\Drupal\dkan_api\Controller\Dataset::patch'}
-  options:
-    _auth: [ 'basic_auth' ]
-  requirements:
-    _permission: 'post put delete datasets through the api'
-dkan_api.dataset_delete:
-  path: '/api/v1/dataset/{uuid}'
-  methods: [DELETE]
-  defaults:
-    { _controller: '\Drupal\dkan_api\Controller\Dataset::delete'}
-  options:
-    _auth: [ 'basic_auth' ]
-  requirements:
-    _permission: 'post put delete datasets through the api'
-dkan_api.organization_get:
-  path: '/api/v1/organization'
-  methods: [GET]
-  defaults:
-    { _controller: '\Drupal\dkan_api\Controller\Organization::getAll'}
-  requirements:
-    _access: 'TRUE'
+# Dynamic routes based on dkan_json_property_api's property_list config.
+route_callbacks:
+  - '\Drupal\dkan_api\Routing\RouteProvider::routes'
diff --git a/modules/custom/dkan_api/dkan_api.services.yml b/modules/custom/dkan_api/dkan_api.services.yml
index 49ec3c5927..24b0617ec0 100644
--- a/modules/custom/dkan_api/dkan_api.services.yml
+++ b/modules/custom/dkan_api/dkan_api.services.yml
@@ -9,13 +9,6 @@ services:
         class: \Drupal\dkan_api\Storage\DrupalNodeDataset
         arguments:
             - '@entity_type.manager'
-            - '@dkan_api.storage.theme_value_referencer'
     dkan_api.storage.organization:
         class: \Drupal\dkan_api\Storage\Organization
         arguments: ['@dkan_api.storage.drupal_node_dataset']
-    dkan_api.storage.theme_value_referencer:
-        class: \Drupal\dkan_api\Storage\ThemeValueReferencer
-        arguments:
-            - '@entity_type.manager'
-            - '@uuid'
-            - '@queue'
diff --git a/modules/custom/dkan_api/src/Controller/Api.php b/modules/custom/dkan_api/src/Controller/Api.php
index 18880cd924..384661eaa5 100644
--- a/modules/custom/dkan_api/src/Controller/Api.php
+++ b/modules/custom/dkan_api/src/Controller/Api.php
@@ -6,10 +6,19 @@
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
+ * Class Api.
  *
+ * @package Drupal\dkan_api\Controller
  */
 abstract class Api extends ControllerBase {
 
+  /**
+   * Represents the data type passed via the HTTP request url schema_id slug.
+   *
+   * @var string
+   */
+  protected $schemaId;
+
   /**
    * Drupal service container.
    *
@@ -25,7 +34,7 @@ abstract class Api extends ControllerBase {
   protected $dkanFactory;
 
   /**
-   *
+   * Api constructor.
    */
   public function __construct(ContainerInterface $container) {
     $this->container = $container;
@@ -33,21 +42,26 @@ public function __construct(ContainerInterface $container) {
   }
 
   /**
-   *
+   * Gets the json schema object.
    */
   abstract protected function getJsonSchema();
 
   /**
-   *
+   * Gets the storage object.
    */
   abstract protected function getStorage();
 
   /**
    * Get all.
    *
+   * @param string $schema_id
+   *   The {schema_id} slug from the HTTP request.
+   *
    * @return \Symfony\Component\HttpFoundation\JsonResponse
+   *   The json response.
    */
-  public function getAll() {
+  public function getAll($schema_id = 'dataset') {
+    $this->schemaId = $schema_id;
 
     $datasets = $this->getEngine()
       ->get();
@@ -73,10 +87,15 @@ function ($json_string) {
    *
    * @param string $uuid
    *   Identifier.
+   * @param string $schema_id
+   *   The {schema_id} slug from the HTTP request.
    *
-   * @return \Symfony\Component\HttpFoundation\JsonResponse Json response.
+   * @return \Symfony\Component\HttpFoundation\JsonResponse
+   *   The json response.
    */
-  public function get($uuid) {
+  public function get($uuid, $schema_id = 'dataset') {
+    $this->schemaId = $schema_id;
+
     try {
 
       $data = $this->getEngine()
@@ -98,9 +117,15 @@ public function get($uuid) {
   /**
    * Implements POST method.
    *
-   * @return \Symfony\Component\HttpFoundation\JsonResponse Json response
+   * @param string $schema_id
+   *   The {schema_id} slug from the HTTP request.
+   *
+   * @return \Symfony\Component\HttpFoundation\JsonResponse
+   *   The json response.
    */
-  public function post() {
+  public function post($schema_id = 'dataset') {
+    $this->schemaId = $schema_id;
+
     /* @var $engine \Sae\Sae */
     $engine = $this->getEngine();
 
@@ -142,10 +167,15 @@ public function post() {
    *
    * @param string $uuid
    *   Identifier.
+   * @param string $schema_id
+   *   The {schema_id} slug from the HTTP request.
    *
-   * @return \Symfony\Component\HttpFoundation\JsonResponse Json response
+   * @return \Symfony\Component\HttpFoundation\JsonResponse
+   *   The json response.
    */
-  public function put($uuid) {
+  public function put($uuid, $schema_id = 'dataset') {
+    $this->schemaId = $schema_id;
+
     /* @var $engine \Sae\Sae */
     $engine = $this->getEngine();
 
@@ -184,10 +214,15 @@ public function put($uuid) {
    *
    * @param string $uuid
    *   Identifier.
+   * @param string $schema_id
+   *   The {schema_id} slug from the HTTP request.
    *
-   * @return \Symfony\Component\HttpFoundation\JsonResponse Json response
+   * @return \Symfony\Component\HttpFoundation\JsonResponse
+   *   The json response.
    */
-  public function patch($uuid) {
+  public function patch($uuid, $schema_id = 'dataset') {
+    $this->schemaId = $schema_id;
+
     /* @var $engine \Sae\Sae */
     $engine = $this->getEngine();
 
@@ -229,10 +264,13 @@ public function patch($uuid) {
    *
    * @param string $uuid
    *   Identifier.
+   * @param string $schema_id
+   *   The {schema_id} slug from the HTTP request.
    *
-   * @return \Symfony\Component\HttpFoundation\JsonResponse Json response
+   * @return \Symfony\Component\HttpFoundation\JsonResponse
+   *   The json response.
    */
-  public function delete($uuid) {
+  public function delete($uuid, $schema_id = 'dataset') {
     /* @var $engine \Sae\Sae */
     $engine = $this->getEngine();
 
@@ -242,9 +280,10 @@ public function delete($uuid) {
   }
 
   /**
-   * Get isntance of.
+   * Get SAE instance.
    *
    * @return \Sae\Sae
+   *   Service Api Engine
    */
   public function getEngine() {
 
diff --git a/modules/custom/dkan_api/src/Controller/Dataset.php b/modules/custom/dkan_api/src/Controller/Dataset.php
index 69179b1aa9..2af572f19e 100644
--- a/modules/custom/dkan_api/src/Controller/Dataset.php
+++ b/modules/custom/dkan_api/src/Controller/Dataset.php
@@ -31,6 +31,7 @@ public function __construct(ContainerInterface $container) {
    * @return \Drupal\dkan_api\Storage\DrupalNodeDataset Dataset
    */
   protected function getStorage() {
+    $this->nodeDataset->setSchema('dataset');
     return $this->nodeDataset;
   }
 
@@ -38,9 +39,18 @@ protected function getStorage() {
    * Get Json Schema.
    *
    * @return string
+   *   Json schema.
    */
   protected function getJsonSchema() {
 
+    // @Todo: mechanism to validate against additional schemas. For now,
+    // validate against the empty object, as it accepts any valid json.
+    if (isset($this->schemaId) && $this->schemaId != 'dataset') {
+      // @codeCoverageIgnoreStart
+      return '{ }';
+      // @codeCoverageIgnoreEnd
+    }
+
     /** @var \Drupal\dkan_schema\SchemaRetriever $retriever */
     $retriever = $this->container
       ->get('dkan_schema.schema_retriever');
diff --git a/modules/custom/dkan_api/src/Routing/RouteProvider.php b/modules/custom/dkan_api/src/Routing/RouteProvider.php
new file mode 100644
index 0000000000..f13436ea94
--- /dev/null
+++ b/modules/custom/dkan_api/src/Routing/RouteProvider.php
@@ -0,0 +1,93 @@
+<?php
+
+namespace Drupal\dkan_api\Routing;
+
+use Symfony\Component\Routing\Route;
+use Symfony\Component\Routing\RouteCollection;
+
+/**
+ *
+ */
+class RouteProvider {
+
+  /**
+   * @return array
+   *   list of json properties being considered from DKAN json property api
+   *   config value.
+   *
+   * @Todo: consolidate with dkan_data ValueReferencer's getPropertyList.
+   */
+  public function getPropertyList() {
+    $list = \Drupal::config('dkan_data.settings')->get('property_list');
+    if ($list) {
+      // Trim and split list on newlines whether Windows, MacOS or Linux.
+      return preg_split(
+        '/\s*\r\n\s*|\s*\r\s*|\s*\n\s*/',
+        trim($list),
+        -1,
+        PREG_SPLIT_NO_EMPTY
+      );
+    }
+    else {
+      return [];
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function routes() {
+    $routes = new RouteCollection();
+    $public_routes = new RouteCollection();
+    $authenticated_routes = new RouteCollection();
+    $schemas = array_merge(['dataset'], $this->getPropertyList());
+
+    foreach ($schemas as $schema) {
+      // GET collection.
+      $get_all = $this->routeHelper($schema, "/api/v1/$schema", 'GET', 'getAll');
+      $public_routes->add("dkan_api.{$schema}.get_all", $get_all);
+      // GET individual.
+      $get = $this->routeHelper($schema, "/api/v1/$schema/{uuid}", 'GET', 'get');
+      $public_routes->add("dkan_api.{$schema}.get", $get);
+      // POST.
+      $post = $this->routeHelper($schema, "/api/v1/$schema", 'POST', 'post');
+      $authenticated_routes->add("dkan_api.{$schema}.post", $post);
+      // PUT.
+      $put = $this->routeHelper($schema, "/api/v1/$schema/{uuid}", 'PUT', 'put');
+      $authenticated_routes->add("dkan_api.{$schema}.put", $put);
+      // PATCH.
+      $patch = $this->routeHelper($schema, "/api/v1/$schema/{uuid}", 'PATCH', 'patch');
+      $authenticated_routes->add("dkan_api.{$schema}.patch", $patch);
+      // DELETE.
+      $delete = $this->routeHelper($schema, "/api/v1/$schema/{uuid}", 'DELETE', 'delete');
+      $authenticated_routes->add("dkan_api.{$schema}.delete", $delete);
+    }
+
+    $public_routes->addRequirements(['_access' => 'TRUE']);
+    $authenticated_routes->addRequirements(['_permission' => 'post put delete datasets through the api']);
+    $authenticated_routes->addOptions(['_auth' => ['basic_auth']]);
+    $routes->addCollection($public_routes);
+    $routes->addCollection($authenticated_routes);
+
+    return $routes;
+  }
+
+  /**
+   * @param string $path
+   * @param string $datasetMethod
+   * @param string $httpVerb
+   * @return Route
+   */
+  protected function routeHelper(string $schema, string $path, string $httpVerb, string $datasetMethod) : Route {
+    $route = new Route(
+      $path,
+      [
+        '_controller' => '\Drupal\dkan_api\Controller\Dataset::' . $datasetMethod,
+        'schema_id' => $schema,
+      ]
+    );
+    $route->setMethods([$httpVerb]);
+    return $route;
+  }
+
+}
diff --git a/modules/custom/dkan_api/src/Storage/DrupalNodeDataset.php b/modules/custom/dkan_api/src/Storage/DrupalNodeDataset.php
index 8d490c9db0..58931d4413 100644
--- a/modules/custom/dkan_api/src/Storage/DrupalNodeDataset.php
+++ b/modules/custom/dkan_api/src/Storage/DrupalNodeDataset.php
@@ -21,26 +21,30 @@ class DrupalNodeDataset implements Storage {
   protected $entityTypeManager;
 
   /**
-   * Theme Value Referencer.
+   * Represents the data type passed via the HTTP request url schema_id slug.
    *
-   * @var Drupal\dkan_api\Storage\ThemeValueReferencer
+   * @var string
    */
-  protected $themeValueReferencer;
+  protected $schemaId;
 
   /**
    * Constructor.
    *
    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
    *   Injected entity type manager.
-   * @param \Drupal\dkan_api\Storage\ThemeValueReferencer $themeValueReferencer
-   *   Injected theme value referencer.
    */
-  public function __construct(
-          EntityTypeManagerInterface $entityTypeManager,
-          ThemeValueReferencer $themeValueReferencer
-    ) {
+  public function __construct(EntityTypeManagerInterface $entityTypeManager) {
     $this->entityTypeManager = $entityTypeManager;
-    $this->themeValueReferencer = $themeValueReferencer;
+  }
+
+  /**
+   * Sets the data type.
+   *
+   * @param $schema_id string
+   *   The HTTP request's schema or data type.
+   */
+  public function setSchema($schema_id) {
+    $this->schemaId = $schema_id;
   }
 
   /**
@@ -67,8 +71,12 @@ protected function getType() {
    */
   public function retrieve(string $id): ?string {
 
+    if (!isset($this->schemaId)) {
+      throw new \Exception("DrupalNodeDataset schemaId not set in retrieve().");
+    }
+
     if (FALSE !== ($node = $this->getNodeByUuid($id))) {
-      return $this->themeDereferenced($node->field_json_metadata->value);
+      return $node->field_json_metadata->value;
     }
 
     throw new \Exception("No data with the identifier {$id} was found.");
@@ -79,17 +87,21 @@ public function retrieve(string $id): ?string {
    */
   public function retrieveAll(): array {
 
+    if (!isset($this->schemaId)) {
+      throw new \Exception("DrupalNodeDataset schemaId not set in retrieveAll().");
+    }
+
     $nodeStorage = $this->getNodeStorage();
 
     $node_ids = $nodeStorage->getQuery()
       ->condition('type', $this->getType())
-      ->condition('field_data_type', 'dataset')
+      ->condition('field_data_type', $this->schemaId)
       ->execute();
 
     $all = [];
     foreach ($node_ids as $nid) {
       $node = $nodeStorage->load($nid);
-      $all[] = $this->themeDereferenced($node->field_json_metadata->value);
+      $all[] = $node->field_json_metadata->value;
     }
     return $all;
   }
@@ -100,10 +112,6 @@ public function retrieveAll(): array {
   public function remove(string $id) {
 
     if (FALSE !== ($node = $this->getNodeByUuid($id))) {
-      // Check for orphan theme references.
-      $this->themeValueReferencer->processDeletedThemes(
-        $node->field_json_metadata->value
-      );
       return $node->delete();
     }
   }
@@ -113,12 +121,12 @@ public function remove(string $id) {
    */
   public function store(string $data, string $id = NULL): string {
 
-    $data = json_decode($data);
-
-    if (isset($data->theme)) {
-      $data->theme = $this->themeValueReferencer->reference($data);
+    if (!isset($this->schemaId)) {
+      $this->schemaId = 'dataset';
     }
 
+    $data = json_decode($data);
+
     if (!$id && isset($data->identifier)) {
       $id = $data->identifier;
     }
@@ -130,13 +138,8 @@ public function store(string $data, string $id = NULL): string {
     /* @var $node \Drupal\node\NodeInterface */
     // update existing node
     if ($node) {
-      $node->field_data_type = "dataset";
+      $node->field_data_type = $this->schemaId;
       $new_data = json_encode($data);
-      // Check for orphan theme references.
-      $this->themeValueReferencer->processDeletedThemes(
-        $node->field_json_metadata->value,
-        $new_data
-      );
       $node->field_json_metadata = $new_data;
       $node->save();
       return $node->uuid();
@@ -149,7 +152,7 @@ public function store(string $data, string $id = NULL): string {
           'title' => $title,
           'type' => 'data',
           'uuid' => $id,
-          'field_data_type' => 'dataset',
+          'field_data_type' => $this->schemaId,
           'field_json_metadata' => json_encode($data),
         ]);
       $node->save();
@@ -212,15 +215,4 @@ protected function getNodeByUuid($uuid) {
     return current($nodes);
   }
 
-  /**
-   * Helper function.
-   */
-  protected function themeDereferenced($json) {
-    $data = json_decode($json);
-    if (isset($data->theme)) {
-      $data->theme = $this->themeValueReferencer->dereference($data);
-    }
-    return json_encode($data);
-  }
-
 }
diff --git a/modules/custom/dkan_api/src/Storage/ThemeValueReferencer.php b/modules/custom/dkan_api/src/Storage/ThemeValueReferencer.php
deleted file mode 100644
index 54a04ff8a9..0000000000
--- a/modules/custom/dkan_api/src/Storage/ThemeValueReferencer.php
+++ /dev/null
@@ -1,241 +0,0 @@
-<?php
-
-declare(strict_types = 1);
-
-namespace Drupal\dkan_api\Storage;
-
-use Drupal\Core\Entity\EntityTypeManagerInterface;
-use Drupal\Component\Uuid\UuidInterface;
-use Drupal\Core\Queue\QueueFactory;
-use stdClass;
-
-/**
- * Replaces human-readable theme values with their corresponding uuids.
- *
- * @package Drupal\dkan_api\Storage
- */
-class ThemeValueReferencer {
-
-  /**
-   * The entity type manager service.
-   *
-   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
-   */
-  protected $entityTypeManager;
-
-  /**
-   * The uuid service.
-   *
-   * @var Drupal\Component\Uuid\UuidInterface
-   */
-  protected $uuidService;
-
-  /**
-   * The queue service.
-   *
-   * @var Drupal\Core\Queue\QueueFactory
-   */
-  protected $queueService;
-
-  /**
-   * Constructor.
-   *
-   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
-   *   Injected entity type manager.
-   */
-  public function __construct(EntityTypeManagerInterface $entityTypeManager, UuidInterface $uuidService, QueueFactory $queueService) {
-    $this->entityTypeManager = $entityTypeManager;
-    $this->uuidService = $uuidService;
-    $this->queueService = $queueService;
-  }
-
-  /**
-   * Returns the uuid references for all themes values.
-   *
-   * @param \stdClass $data
-   *   The object from the json data string.
-   *
-   * @return mixed
-   *   An array of uuid, or NULL.
-   */
-  public function reference(stdClass $data) {
-    if (!isset($data->theme) || !is_array($data->theme)) {
-      return NULL;
-    }
-    $themes = [];
-    foreach ($data->theme as $theme) {
-      $uuid = $this->referenceSingle($theme);
-      if (!$uuid) {
-        $uuid = $this->createThemeReference($theme);
-      }
-      // Return the existing or generated uuid, if not keep the original value.
-      if ($uuid) {
-        $themes[] = $uuid;
-      }
-      else {
-        $themes[] = $theme;
-      }
-    }
-    return $themes;
-  }
-
-  /**
-   * Returns a single uuid reference for a particular theme value.
-   *
-   * If a corresponding existing uuid is not found, a theme data item is saved
-   * and its uuid returned.
-   *
-   * @param string $theme
-   *   Human-readable theme value.
-   *
-   * @return mixed
-   *   string containing uuid, or NULL.
-   */
-  protected function referenceSingle(string $theme) {
-    $nodes = $this->entityTypeManager
-      ->getStorage('node')
-      ->loadByProperties([
-        'field_data_type' => "theme",
-        'title' => $theme,
-      ]);
-
-    if ($node = reset($nodes)) {
-      return $node->uuid->value;
-    }
-    return NULL;
-  }
-
-  /**
-   * Generate and save a json theme item.
-   *
-   * @param string $theme
-   *   Human-readable theme value.
-   *
-   * @return string
-   *   The new theme data item's uuid.
-   */
-  protected function createThemeReference(string $theme) {
-    $today = date('Y-m-d');
-
-    // Create theme json.
-    $data = new stdClass();
-    $data->title = $theme;
-    $data->identifier = $this->uuidService->generate();
-    $data->created = $today;
-    $data->modified = $today;
-
-    // Create new data node for this theme.
-    $node = $this->entityTypeManager
-      ->getStorage('node')
-      ->create([
-        'title' => $theme,
-        'type' => 'data',
-        'uuid' => $data->identifier,
-        'field_data_type' => 'theme',
-        'field_json_metadata' => json_encode($data),
-      ]);
-    $node->save();
-
-    return $node->uuid();
-  }
-
-  /**
-   * Returns the human-readable theme values from uuids.
-   *
-   * @param \stdClass $data
-   *   The object from the json data string.
-   *
-   * @return mixed
-   *   An array of theme values, or NULL.
-   */
-  public function dereference(stdClass $data) {
-    if (!isset($data->theme) || !is_array($data->theme)) {
-      return NULL;
-    }
-    $themes = [];
-    foreach ($data->theme as $theme) {
-      $themes[] = $this->dereferenceSingle($theme);
-    }
-
-    if (!empty($themes)) {
-      return $themes;
-    }
-    else {
-      return NULL;
-    }
-  }
-
-  /**
-   * Returns the human-readable theme value from its uuid.
-   *
-   * @param string $str
-   *   The string could either be a uuid or a human-readable theme value.
-   *
-   * @return string
-   *   The theme value.
-   */
-  protected function dereferenceSingle(string $str) {
-    $nodes = $this->entityTypeManager
-      ->getStorage('node')
-      ->loadByProperties([
-        'field_data_type' => "theme",
-        'uuid' => $str,
-      ]);
-    if ($node = reset($nodes)) {
-      return $node->title->value;
-    }
-    return $str;
-  }
-
-  /**
-   * Queue deleted themes for processing, as they may be orphans.
-   *
-   * @param string $old
-   *   Json string of item being replaced.
-   * @param string $new
-   *   Json string of item doing the replacing.
-   *
-   * @return int
-   *   The number of items queued for processing.
-   */
-  public function processDeletedThemes(string $old, string $new = "{}") {
-    $themes_removed = $this->themesRemoved($old, $new);
-
-    $orphan_theme_queue = $this->queueService->get('orphan_theme_processor');
-    foreach ($themes_removed as $theme_removed) {
-      // @Todo: Only add to the queue when uuid doesn't already exists in it.
-      $orphan_theme_queue->createItem($theme_removed);
-    }
-  }
-
-  /**
-   * Returns an array of theme uuid(s) being removed as the data changes.
-   *
-   * @param string $old
-   *   Json string of item being replaced.
-   * @param string $new
-   *   Json string of item doing the replacing.
-   *
-   * @return array
-   *   Array of theme uuid(s).
-   */
-  public function themesRemoved(string $old, string $new = "{}"): array {
-    $old_data = json_decode($old);
-    if (!isset($old_data->theme)) {
-      // No theme to potentially delete nor check for orphan.
-      return [];
-    }
-    $old_themes = $old_data->theme;
-
-    $new_data = json_decode($new);
-    if (!isset($new_data->theme)) {
-      $new_themes = [];
-    }
-    else {
-      $new_themes = $new_data->theme;
-    }
-
-    return array_diff($old_themes, $new_themes);
-  }
-
-}
diff --git a/modules/custom/dkan_api/tests/src/Unit/Storage/DrupalNodeDatasetTest.php b/modules/custom/dkan_api/tests/src/Unit/Storage/DrupalNodeDatasetTest.php
index 9a5e7ad7b5..df04b7c988 100644
--- a/modules/custom/dkan_api/tests/src/Unit/Storage/DrupalNodeDatasetTest.php
+++ b/modules/custom/dkan_api/tests/src/Unit/Storage/DrupalNodeDatasetTest.php
@@ -6,7 +6,6 @@
 use Drupal\dkan_common\Tests\DkanTestBase;
 use Drupal\dkan_api\Storage\DrupalNodeDataset;
 use Drupal\node\NodeStorageInterface;
-use Drupal\dkan_api\Storage\ThemeValueReferencer;
 use Drupal\dkan_datastore\Manager\DatastoreManagerBuilderHelper;
 use Drupal\dkan_datastore\Manager\DeferredImportQueuer;
 use Dkan\Datastore\Resource;
@@ -26,22 +25,17 @@ class DrupalNodeDatasetTest extends DkanTestBase {
    */
   public function testConstruct() {
     $mockEntityTypeManager = $this->createMock(EntityTypeManagerInterface::class);
-    $mockThemeValueReferencer = $this->createMock(ThemeValueReferencer::class);
     $mock = $this->getMockBuilder(DrupalNodeDataset::class)
       ->disableOriginalConstructor()
       ->getMock();
 
     // Assert.
-    $mock->__construct($mockEntityTypeManager, $mockThemeValueReferencer);
+    $mock->__construct($mockEntityTypeManager);
 
     $this->assertSame(
             $mockEntityTypeManager,
             $this->readAttribute($mock, 'entityTypeManager')
     );
-    $this->assertSame(
-            $mockThemeValueReferencer,
-            $this->readAttribute($mock, 'themeValueReferencer')
-    );
   }
 
   /**
@@ -205,7 +199,7 @@ public function testEnqueueDeferredImportOnException() {
    */
   public function testRemainingMethods() {
 
-    $this->markTestIncomplete('Review of other methods in ' . DrupalNodeDataset::class . ' pending reivew of refactor.');
+    $this->markTestIncomplete('Review of other methods in ' . DrupalNodeDataset::class . ' pending review of refactor.');
   }
 
 }
diff --git a/modules/custom/dkan_api/tests/src/Unit/Storage/OrganizationTest.php b/modules/custom/dkan_api/tests/src/Unit/Storage/OrganizationTest.php
index 8d5048d7e7..9e9d9a7b4d 100644
--- a/modules/custom/dkan_api/tests/src/Unit/Storage/OrganizationTest.php
+++ b/modules/custom/dkan_api/tests/src/Unit/Storage/OrganizationTest.php
@@ -39,7 +39,7 @@ public function testConstruct() {
    */
   public function testRemainingMethods() {
 
-    $this->markTestIncomplete('Review of other methods in ' . DrupalNodeDataset::class . ' pending reivew of refactor.');
+    $this->markTestIncomplete('Review of other methods in ' . DrupalNodeDataset::class . ' pending review of refactor.');
   }
 
 }
diff --git a/modules/custom/dkan_api/tests/src/Unit/Storage/ThemeValueReferencerTest.php b/modules/custom/dkan_api/tests/src/Unit/Storage/ThemeValueReferencerTest.php
deleted file mode 100644
index f42b7736bc..0000000000
--- a/modules/custom/dkan_api/tests/src/Unit/Storage/ThemeValueReferencerTest.php
+++ /dev/null
@@ -1,518 +0,0 @@
-<?php
-
-namespace Drupal\Tests\dkan_api\Unit\Storage;
-
-use Drupal\Core\Entity\EntityTypeManagerInterface;
-use Drupal\dkan_common\Tests\DkanTestBase;
-use Drupal\dkan_api\Storage\ThemeValueReferencer;
-use Drupal\Component\Uuid\UuidInterface;
-use Drupal\Core\Queue\QueueFactory;
-use Drupal\Core\Queue\QueueInterface;
-use Drupal\Core\Entity\EntityStorageInterface;
-use Drupal\node\NodeInterface;
-use Drupal\Core\Entity\EntityInterface;
-use stdClass;
-
-/**
- * Tests Drupal\dkan_api\Storage\ThemeValueReferencer.
- *
- * @coversDefaultClass \Drupal\dkan_api\Storage\ThemeValueReferencer
- * @group dkan_api
- */
-class ThemeValueReferencerTest extends DkanTestBase {
-
-  /**
-   * Tests the constructor.
-   */
-  public function testConstruct() {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->setMethods(NULL)
-      ->disableOriginalConstructor()
-      ->getMock();
-
-    $mockEntityTypeManager = $this->createMock(EntityTypeManagerInterface::class);
-    $mockUuidInterface     = $this->createMock(UuidInterface::class);
-    $mockQueueFactory      = $this->createMock(QueueFactory::class);
-
-    // Assert.
-    $mock->__construct($mockEntityTypeManager, $mockUuidInterface, $mockQueueFactory);
-
-    $this->assertSame($mockEntityTypeManager, $this->readAttribute($mock, 'entityTypeManager'));
-    $this->assertSame($mockUuidInterface, $this->readAttribute($mock, 'uuidService'));
-    $this->assertSame($mockQueueFactory, $this->readAttribute($mock, 'queueService'));
-  }
-
-  /**
-   * Provides data for testing referenceSingle function.
-   */
-  public function dataTestReferenceSingle() {
-    $mockNode = $this->createMock(NodeInterface::class);
-    $expected = uniqid('a-uuid');
-    $mockNode->uuid = (object) ['value' => $expected];
-
-    return [
-        ['foobar', [$mockNode], $expected],
-        ['barfoo', [], NULL],
-    ];
-  }
-
-  /**
-   * Tests the referenceSingle function.
-   *
-   * @dataProvider dataTestReferenceSingle
-   *
-   * @param string $theme
-   *   Theme uuid.
-   * @param array $nodes
-   *   Array of node objects with uuid->value properties.
-   * @param mixed $expected
-   *   Expected result.
-   */
-  public function testReferenceSingle(string $theme, array $nodes, $expected) {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->setMethods(NULL)
-      ->disableOriginalConstructor()
-      ->getMock();
-
-    $mockEntityTypeManager = $this->getMockBuilder(EntityTypeManagerInterface::class)
-      ->setMethods([
-        'getStorage',
-      ])
-      ->getMockForAbstractClass();
-
-    $this->writeProtectedProperty($mock, 'entityTypeManager', $mockEntityTypeManager);
-
-    $mockNodeStorage = $this->getMockBuilder(EntityStorageInterface::class)
-      ->setMethods([
-        'loadByProperties',
-      ])
-      ->getMockForAbstractClass();
-
-    // Expect.
-    $mockEntityTypeManager->expects($this->once())
-      ->method('getStorage')
-      ->with('node')
-      ->willReturn($mockNodeStorage);
-
-    $mockNodeStorage->expects($this->once())
-      ->method('loadByProperties')
-      ->with([
-        'field_data_type' => "theme",
-        'title'           => $theme,
-      ])
-      ->willReturn($nodes);
-
-    // Assert.
-    $actual = $this->invokeProtectedMethod($mock, 'referenceSingle', $theme);
-
-    $this->assertEquals($expected, $actual);
-  }
-
-  /**
-   * Provides a list of old and new json strings to test themes being removed.
-   */
-  public function dataTestThemesRemoved() {
-    return [
-      ['{}', '{}', []],
-      ['{"theme":["Theme One"]}', '{"key":"value"}', ['Theme One']],
-      ['{"theme":["Theme One", "Theme Two"]}', '{"theme":["Theme One"]}', [1 => 'Theme Two']],
-    ];
-  }
-
-  /**
-   * Tests the themesRemoved function.
-   *
-   * @dataProvider dataTestThemesRemoved
-   *
-   * @param string $old
-   *   Existing json string.
-   * @param string $new
-   *   Incoming json string.
-   * @param array $expected
-   *   Expected array containing themes removed between old and new.
-   */
-  public function testThemesRemoved($old, $new, array $expected) {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->disableOriginalConstructor()
-      ->setMethods(NULL)
-      ->getMock();
-
-    // Assert.
-    $this->assertEquals($expected, $mock->themesRemoved($old, $new));
-  }
-
-  /**
-   * Provides test data for function dereferenceSingle.
-   */
-  public function dataTestDereferenceSingle() {
-    $mockNode = $this->createMock(NodeInterface::class);
-    $expected = uniqid('a-theme');
-    $mockNode->title = (object) ['value' => $expected];
-
-    return [
-      ['foobar', [$mockNode], $expected],
-      ['a-uuid-that-does-not-exist', [], 'a-uuid-that-does-not-exist'],
-    ];
-  }
-
-  /**
-   * Tests the dereferenceSingle function.
-   *
-   * @dataProvider dataTestDereferenceSingle
-   *
-   * @param string $str
-   *   The human-readable theme value or a theme uuid.
-   * @param array $nodes
-   *   An array of node objects with title->value property.
-   * @param mixed $expected
-   *   Expected result from dereferenceSingle when passed test data.
-   */
-  public function testDereferenceSingle($str, array $nodes, $expected) {
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->setMethods(NULL)
-      ->disableOriginalConstructor()
-      ->getMock();
-
-    $mockEntityTypeManager = $this->getMockBuilder(EntityTypeManagerInterface::class)
-      ->setMethods([
-        'getStorage',
-      ])
-      ->getMockForAbstractClass();
-
-    $this->writeProtectedProperty($mock, 'entityTypeManager', $mockEntityTypeManager);
-
-    $mockNodeStorage = $this->getMockBuilder(EntityStorageInterface::class)
-      ->setMethods([
-        'loadByProperties',
-      ])
-      ->getMockForAbstractClass();
-
-    // Expect.
-    $mockEntityTypeManager->expects($this->once())
-      ->method('getStorage')
-      ->with('node')
-      ->willReturn($mockNodeStorage);
-
-    $mockNodeStorage->expects($this->once())
-      ->method('loadByProperties')
-      ->with([
-        'field_data_type' => "theme",
-        'uuid'           => $str,
-      ])
-      ->willReturn($nodes);
-
-    // Assert.
-    $actual = $this->invokeProtectedMethod($mock, 'dereferenceSingle', $str);
-    $this->assertEquals($expected, $actual);
-  }
-
-  /**
-   * Provides data without or empty themes to test function dereference.
-   */
-  public function dataTestDereferenceWithoutThemes() {
-    return [
-      [
-        (object) ["non-theme" => "some value"],
-        NULL,
-      ],
-      [
-        (object) ["theme" => "a string"],
-        NULL,
-      ],
-      [
-        (object) ["theme" => []],
-        NULL,
-      ],
-    ];
-  }
-
-  /**
-   * Tests function dereference without valid theme values.
-   *
-   * @dataProvider dataTestDereferenceWithoutThemes
-   *
-   * @param \stdClass $data
-   *   Object created from json data.
-   * @param mixed $expected
-   *   Expected result from dereference when passed test data.
-   */
-  public function testDereferenceWithoutThemes(\stdClass $data, $expected) {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->disableOriginalConstructor()
-      ->setMethods(NULL)
-      ->getMock();
-
-    // Assert.
-    $this->assertEquals($expected, $mock->dereference($data));
-  }
-
-  /**
-   * Tests function dereference with valid theme values.
-   */
-  public function testDereferenceWithThemes() {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->disableOriginalConstructor()
-      ->setMethods(['dereferenceSingle'])
-      ->getMock();
-
-    $data = (object) ["theme" => [uniqid('theme-with-uuid-')]];
-    $expected = 'corresponding-uuid';
-
-    // Expect.
-    $mock->expects($this->once())
-      ->method('dereferenceSingle')
-      ->with($data->theme[0])
-      ->willReturn($expected);
-
-    // Assert.
-    $this->assertEquals([$expected], $mock->dereference($data));
-  }
-
-  /**
-   * Provides data without or empty themes to test function reference.
-   */
-  public function dataTestReferenceWithoutThemes() {
-    return [
-      [
-        (object) ["non-theme" => "some value"],
-        NULL,
-      ],
-      [
-        (object) ["theme" => "a string"],
-        NULL,
-      ],
-      [
-        (object) ["theme" => []],
-        [],
-      ],
-    ];
-  }
-
-  /**
-   * Tests function reference without valid themes.
-   *
-   * @dataProvider dataTestReferenceWithoutThemes
-   *
-   * @param \stdClass $data
-   *   Object created from json data.
-   * @param mixed $expected
-   *   Expected result from dereference when passed test data.
-   */
-  public function testReferenceWithoutThemes(\stdClass $data, $expected) {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->disableOriginalConstructor()
-      ->setMethods(NULL)
-      ->getMock();
-
-    // Assert.
-    $this->assertEquals($expected, $mock->reference($data));
-  }
-
-  /**
-   * Tests function reference with valid theme values.
-   */
-  public function testReferenceWithExistingThemes() {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->disableOriginalConstructor()
-      ->setMethods(['referenceSingle'])
-      ->getMock();
-
-    $data = (object) ["theme" => [uniqid('theme-with-uuid-')]];
-    $expect = 'corresponding-uuid';
-
-    // Expect.
-    $mock->expects($this->once())
-      ->method('referenceSingle')
-      ->with($data->theme[0])
-      ->willReturn($expect);
-
-    // Assert.
-    $this->assertEquals([$expect], $mock->reference($data));
-  }
-
-  /**
-   * Tests the creation of new theme references.
-   */
-  public function testReferenceCreatingNewThemeReference() {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->disableOriginalConstructor()
-      ->setMethods(['referenceSingle', 'createThemeReference'])
-      ->getMock();
-
-    $data = (object) ["theme" => [uniqid('theme-with-uuid-')]];
-    $expect = 'corresponding-uuid';
-
-    // Expect.
-    $mock->expects($this->once())
-      ->method('referenceSingle')
-      ->with($data->theme[0])
-      ->willReturn(NULL);
-    $mock->expects($this->once())
-      ->method('createThemeReference')
-      ->with($data->theme[0])
-      ->willReturn($expect);
-
-    // Assert.
-    $this->assertEquals([$expect], $mock->reference($data));
-  }
-
-  /**
-   * Tests the outcome of failing to create a new theme reference, resulting
-   * in the theme value remaining its human-readable string.
-   */
-  public function testReferenceFailsAtCreatingNewThemeReference() {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->disableOriginalConstructor()
-      ->setMethods(['referenceSingle', 'createThemeReference'])
-      ->getMock();
-
-    $human_readable_value = uniqid('human-readable-theme-value');
-    $data = (object) ["theme" => [$human_readable_value]];
-
-    // Expect.
-    $mock->expects($this->once())
-      ->method('referenceSingle')
-      ->with($data->theme[0])
-      ->willReturn(NULL);
-    $mock->expects($this->once())
-      ->method('createThemeReference')
-      ->with($data->theme[0])
-      ->willReturn(FALSE);
-
-    // Assert.
-    $this->assertEquals([$human_readable_value], $mock->reference($data));
-  }
-
-  /**
-   * Tests the processDeletedThemes function.
-   */
-  public function testProcessDeletedThemes() {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->disableOriginalConstructor()
-      ->setMethods([
-        'themesRemoved',
-      ])
-      ->getMock();
-    $mockQueueFactory = $this->getMockBuilder(QueueFactory::class)
-      ->disableOriginalConstructor()
-      ->setMethods([
-        'get',
-      ])
-      ->getMockForAbstractClass();
-    $this->writeProtectedProperty($mock, 'queueService', $mockQueueFactory);
-
-    $mockQueueInterface = $this->getMockBuilder(QueueInterface::class)
-      ->setMethods([
-        'createItem',
-      ])
-      ->getMockForAbstractClass();
-
-    $old = '{"theme":["Theme One", "Theme Two", "Theme Three"]}';
-    $new = '{"theme":["Theme Two"]}';
-    $themes_removed = ["Theme One", "Theme Three"];
-
-    // Expect.
-    $mock->expects($this->once())
-      ->method('themesRemoved')
-      ->with($old, $new)
-      ->willReturn($themes_removed);
-    $mockQueueFactory->expects($this->atLeastOnce())
-      ->method('get')
-      ->with('orphan_theme_processor')
-      ->willReturn($mockQueueInterface);
-    $mockQueueInterface->expects($this->exactly(2))
-      ->method('createItem')
-      ->withConsecutive([$themes_removed[0]], [$themes_removed[1]])
-      ->willReturnOnConsecutiveCalls(TRUE, TRUE);
-
-    $mock->processDeletedThemes($old, $new);
-  }
-
-  /**
-   * Tests the createThemeReference function.
-   */
-  public function testCreateThemeReference() {
-    // Setup.
-    $mock = $this->getMockBuilder(ThemeValueReferencer::class)
-      ->disableOriginalConstructor()
-      ->setMethods(NULL)
-      ->getMock();
-
-    $mockUuidInterface = $this->getMockBuilder(UuidInterface::class)
-      ->disableOriginalConstructor()
-      ->setMethods([
-        'generate',
-      ])
-      ->getMockForAbstractClass();
-    $this->writeProtectedProperty($mock, 'uuidService', $mockUuidInterface);
-
-    $mockEntityTypeManager = $this->getMockBuilder(EntityTypeManagerInterface::class)
-      ->setMethods([
-        'getStorage',
-      ])
-      ->getMockForAbstractClass();
-    $this->writeProtectedProperty($mock, 'entityTypeManager', $mockEntityTypeManager);
-
-    $mockNodeStorage = $this->getMockBuilder(EntityStorageInterface::class)
-      ->setMethods([
-        'create',
-      ])
-      ->getMockForAbstractClass();
-
-    $mockEntityInterface = $this->getMockBuilder(EntityInterface::class)
-      ->setMethods([
-        'save',
-        'uuid',
-      ])
-      ->getMockForAbstractClass();
-
-    $theme = uniqid('some-theme-');
-    $uuid = uniqid('some-uuid-');
-    $today = date('Y-m-d');
-    $data = new stdClass();
-    $data->title = $theme;
-    $data->identifier = $uuid;
-    $data->created = $today;
-    $data->modified = $today;
-
-    // Expect.
-    $mockUuidInterface->expects($this->once())
-      ->method('generate')
-      ->willReturn($uuid);
-    $mockEntityTypeManager->expects($this->once())
-      ->method('getStorage')
-      ->with('node')
-      ->willReturn($mockNodeStorage);
-    $mockNodeStorage->expects($this->once())
-      ->method('create')
-      ->with([
-        'title' => $theme,
-        'type' => 'data',
-        'uuid' => $uuid,
-        'field_data_type' => 'theme',
-        'field_json_metadata' => json_encode($data),
-      ])
-      ->willReturn($mockEntityInterface);
-    $mockEntityInterface->expects($this->once())
-      ->method('save')
-      ->willReturn(1);
-    $mockEntityInterface->expects($this->once())
-      ->method('uuid')
-      ->willReturn($uuid);
-
-    // Assert.
-    $actual = $this->invokeProtectedMethod($mock, 'createThemeReference', $theme);
-    $this->assertEquals($uuid, $actual);
-  }
-
-}
diff --git a/modules/custom/dkan_common/dkan_common.links.menu.yml b/modules/custom/dkan_common/dkan_common.links.menu.yml
new file mode 100644
index 0000000000..abee4c50be
--- /dev/null
+++ b/modules/custom/dkan_common/dkan_common.links.menu.yml
@@ -0,0 +1,5 @@
+dkan_common.admin_config_dkan:
+  route_name: dkan_common.admin_config_dkan
+  title: DKAN
+  parent: system.admin_config
+  description: Modify DKAN configuration.
diff --git a/modules/custom/dkan_common/dkan_common.routing.yml b/modules/custom/dkan_common/dkan_common.routing.yml
new file mode 100644
index 0000000000..bd8577cd1b
--- /dev/null
+++ b/modules/custom/dkan_common/dkan_common.routing.yml
@@ -0,0 +1,6 @@
+dkan_common.admin_config_dkan:
+  path: '/admin/config/dkan'
+  defaults:
+    _controller: '\Drupal\system\Controller\SystemController::systemAdminMenuBlockPage'
+  requirements:
+    _permission: 'access administration pages'
diff --git a/modules/custom/dkan_data/config/install/dkan_data.settings.yml b/modules/custom/dkan_data/config/install/dkan_data.settings.yml
new file mode 100644
index 0000000000..230817fad9
--- /dev/null
+++ b/modules/custom/dkan_data/config/install/dkan_data.settings.yml
@@ -0,0 +1,4 @@
+property_list: |
+  theme
+  keyword
+  organization
diff --git a/modules/custom/dkan_data/dkan_data.links.menu.yml b/modules/custom/dkan_data/dkan_data.links.menu.yml
new file mode 100644
index 0000000000..22bcb7a89b
--- /dev/null
+++ b/modules/custom/dkan_data/dkan_data.links.menu.yml
@@ -0,0 +1,5 @@
+dkan_data.api_settings_form:
+  title: Dataset properties
+  route_name: dkan_data.config_settings
+  description: Configure dataset properties for referencing and API endpoint.
+  parent: dkan_common.admin_config_dkan
\ No newline at end of file
diff --git a/modules/custom/dkan_data/dkan_data.module b/modules/custom/dkan_data/dkan_data.module
index 813b730fb4..e4bf68d3bf 100644
--- a/modules/custom/dkan_data/dkan_data.module
+++ b/modules/custom/dkan_data/dkan_data.module
@@ -14,12 +14,14 @@ function dkan_data_node_load(array $entities) {
 
   foreach ($entities as $entity) {
     if ($entity->bundle() == "data" && $entity->field_data_type->value == "dataset") {
-      $metadata = json_decode($entity->get('field_json_metadata')->value);
-      if (isset($metadata->theme)) {
-        $referencer = Drupal::service("dkan_api.storage.theme_value_referencer");
-        $metadata->theme = $referencer->dereference($metadata);
-        $entity->set('field_json_metadata', json_encode($metadata));
-      }
+      // Temporarily save the raw json metadata, for later use.
+      $metadata_string = $entity->get('field_json_metadata')->value;
+      $entity->referenced_metadata = $metadata_string;
+      // Dereference dataset properties.
+      $metadata_obj = json_decode($metadata_string);
+      $referencer = Drupal::service("dkan_data.value_referencer");
+      $metadata_obj = $referencer->dereference($metadata_obj);
+      $entity->set('field_json_metadata', json_encode($metadata_obj));
     }
   }
 
@@ -34,6 +36,10 @@ function dkan_data_entity_presave(EntityInterface $entity) {
     return;
   }
 
+  if ($entity->get('field_data_type')->value != 'dataset') {
+    return;
+  }
+
   $entityType = $entity->getEntityTypeId();
 
   $metadata = json_decode($entity->get('field_json_metadata')->value);
@@ -55,12 +61,30 @@ function dkan_data_entity_presave(EntityInterface $entity) {
     $entity->set('uuid', $metadata->identifier);
   }
 
-  if (isset($metadata->theme)) {
-    $referencer = Drupal::service("dkan_api.storage.theme_value_referencer");
-    $metadata->theme = $referencer->reference($metadata);
+  // Reference the dataset's values, and update our json metadata.
+  $referencer = Drupal::service("dkan_data.value_referencer");
+  $metadata = $referencer->reference($metadata);
+  $entity->set('field_json_metadata', json_encode($metadata));
+
+  // Check for possible orphan property references when updating a dataset.
+  if (isset($entity->original)) {
+    $referencer->processReferencesInUpdatedDataset(
+      json_decode($entity->referenced_metadata),
+      $metadata
+    );
   }
+}
 
-  $entity->set('field_json_metadata', json_encode($metadata));
+/**
+ * Implements hook_ENTITY_TYPE_predelete().
+ */
+function dkan_data_node_predelete(EntityInterface $entity) {
+  // Check for possible orphan property references when deleting a dataset.
+  if ($entity->bundle() == 'data' && $entity->get('field_data_type')->value == 'dataset') {
+    $referenced_dataset = json_decode($entity->referenced_metadata);
+    $referencer = Drupal::service("dkan_data.value_referencer");
+    $referencer->processReferencesInDeletedDataset($referenced_dataset);
+  }
 }
 
 /**
diff --git a/modules/custom/dkan_data/dkan_data.routing.yml b/modules/custom/dkan_data/dkan_data.routing.yml
new file mode 100644
index 0000000000..5ccd7894ce
--- /dev/null
+++ b/modules/custom/dkan_data/dkan_data.routing.yml
@@ -0,0 +1,8 @@
+dkan_data.config_settings:
+  path: '/admin/config/dkan/properties'
+  defaults:
+    _form: '\Drupal\dkan_data\Form\DkanDataSettingsForm'
+  requirements:
+    _permission: 'access administration pages'
+  options:
+    _admin_route: TRUE
diff --git a/modules/custom/dkan_data/dkan_data.services.yml b/modules/custom/dkan_data/dkan_data.services.yml
index bf10abb49a..1335c4bcfa 100644
--- a/modules/custom/dkan_data/dkan_data.services.yml
+++ b/modules/custom/dkan_data/dkan_data.services.yml
@@ -3,3 +3,10 @@ services:
     class: \Drupal\dkan_data\ConfigurationOverrider
     tags:
       - {name: config.factory.override, priority: 5}
+  dkan_data.value_referencer:
+    class: \Drupal\dkan_data\ValueReferencer
+    arguments:
+      - '@entity_type.manager'
+      - '@uuid'
+      - '@config.factory'
+      - '@queue'
diff --git a/modules/custom/dkan_data/src/Form/DkanDataSettingsForm.php b/modules/custom/dkan_data/src/Form/DkanDataSettingsForm.php
new file mode 100644
index 0000000000..a6d46e94fd
--- /dev/null
+++ b/modules/custom/dkan_data/src/Form/DkanDataSettingsForm.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace Drupal\dkan_data\Form;
+
+use Drupal\Core\Form\ConfigFormBase;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Class DkanDataSettingsForm.
+ *
+ * @package Drupal\dkan_data\Form
+ * @codeCoverageIgnore
+ */
+class DkanDataSettingsForm extends ConfigFormBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getEditableConfigNames() {
+    return [
+      'dkan_data.settings',
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'dkan_data_settings_form';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state) {
+    $config = $this->config('dkan_data.settings');
+    $form['property_list'] = [
+      '#type' => 'textarea',
+      '#title' => $this->t('List of dataset properties to be referenced'),
+      '#description' => $this->t('Separate properties by a new line.'),
+      '#default_value' => $config->get('property_list'),
+    ];
+    return parent::buildForm($form, $form_state);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    parent::submitForm($form, $form_state);
+
+    $this->config('dkan_data.settings')
+      ->set('property_list', $form_state->getValue('property_list'))
+      ->save();
+
+    // Rebuild routes, without clearing all caches.
+    \Drupal::service("router.builder")->rebuild();
+  }
+
+}
diff --git a/modules/custom/dkan_api/src/Plugin/QueueWorker/OrphanThemeProcessor.php b/modules/custom/dkan_data/src/Plugin/QueueWorker/OrphanReferenceProcessor.php
similarity index 56%
rename from modules/custom/dkan_api/src/Plugin/QueueWorker/OrphanThemeProcessor.php
rename to modules/custom/dkan_data/src/Plugin/QueueWorker/OrphanReferenceProcessor.php
index ff3f1ffd57..c222e8a911 100644
--- a/modules/custom/dkan_api/src/Plugin/QueueWorker/OrphanThemeProcessor.php
+++ b/modules/custom/dkan_data/src/Plugin/QueueWorker/OrphanReferenceProcessor.php
@@ -2,7 +2,7 @@
 
 declare(strict_types = 1);
 
-namespace Drupal\dkan_api\Plugin\QueueWorker;
+namespace Drupal\dkan_data\Plugin\QueueWorker;
 
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
@@ -10,15 +10,17 @@
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
- * Verifies if a theme is orphaned, then deletes it.
+ * Verifies if a dataset property reference is orphaned, then deletes it.
  *
  * @QueueWorker(
- *   id = "orphan_theme_processor",
- *   title = @Translation("Task Worker: Verify then delete orphaned theme"),
+ *   id = "orphan_reference_processor",
+ *   title = @Translation("Task Worker: Check for orphaned property reference"),
  *   cron = {"time" = 15}
  * )
+ *
+ * @codeCoverageIgnore
  */
-class OrphanThemeProcessor extends QueueWorkerBase implements ContainerFactoryPluginInterface {
+class OrphanReferenceProcessor extends QueueWorkerBase implements ContainerFactoryPluginInterface {
 
   /**
    * The entity type manager service.
@@ -59,29 +61,47 @@ public static function create(ContainerInterface $container, array $configuratio
   /**
    * {@inheritdoc}
    */
-  public function processItem($uuid) {
+  public function processItem($data) {
+    $property_id = $data[0];
+    $uuid = $data[1];
+
+    // Search datasets using this uuid for this property id.
     $datasets = $this->entityTypeManager->getStorage('node')
       ->loadByProperties([
         'field_data_type' => 'dataset',
       ]);
-
     foreach ($datasets as $dataset) {
-      $data = json_decode($dataset->field_json_metadata->value);
-      $themes = $data->theme ?? [];
-      if (in_array($uuid, $themes)) {
+      $data = json_decode($dataset->referenced_metadata);
+      $value = $data->{$property_id};
+      // Check if uuid is found either directly or in an array.
+      $uuid_is_value = $uuid == $value;
+      $uuid_found_in_array = is_array($value) && in_array($uuid, $value);
+      if ($uuid_is_value || $uuid_found_in_array) {
         // Uuid found in use, abort.
         return;
       }
     }
 
-    // Theme uuid not found in any dataset, safe to delete.
-    $themes = $this->entityTypeManager->getStorage('node')
+    // Value reference uuid not found in any dataset, therefore safe to delete.
+    $this->deleteReference($property_id, $uuid);
+  }
+
+  /**
+   * Deletes a reference.
+   *
+   * @param string $property_id
+   *   The property id.
+   * @param string $uuid
+   *   The uuid.
+   */
+  protected function deleteReference(string $property_id, string $uuid) {
+    $references = $this->entityTypeManager->getStorage('node')
       ->loadByProperties([
-        'field_data_type' => 'theme',
+        'field_data_type' => $property_id,
         'uuid' => $uuid,
       ]);
-    if (FALSE !== ($theme = reset($themes))) {
-      $theme->delete();
+    if (FALSE !== ($reference = reset($references))) {
+      $reference->delete();
     }
   }
 
diff --git a/modules/custom/dkan_data/src/ValueReferencer.php b/modules/custom/dkan_data/src/ValueReferencer.php
new file mode 100644
index 0000000000..1f9d6bb2d1
--- /dev/null
+++ b/modules/custom/dkan_data/src/ValueReferencer.php
@@ -0,0 +1,405 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\dkan_data;
+
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Component\Uuid\UuidInterface;
+use Drupal\Core\Queue\QueueFactory;
+use stdClass;
+
+/**
+ * Replaces some dataset property values with references, or vice versa.
+ *
+ * @package Drupal\dkan_api\Storage
+ */
+class ValueReferencer {
+
+  /**
+   * The entity type manager service.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * The uuid service.
+   *
+   * @var \Drupal\Component\Uuid\UuidInterface
+   */
+  protected $uuidService;
+
+  /**
+   * The config factory service.
+   *
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
+   */
+  protected $configService;
+
+  /**
+   * The queue service.
+   *
+   * @var \Drupal\Core\Queue\QueueFactory
+   */
+  protected $queueService;
+
+  /**
+   * ValueReferencer constructor.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
+   *   Injected entity type manager.
+   * @param \Drupal\Component\Uuid\UuidInterface $uuidService
+   *   Injected uuid service.
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $configService
+   *   Injected config service.
+   * @param \Drupal\Core\Queue\QueueFactory $queueService
+   *   Injected queue service.
+   */
+  public function __construct(EntityTypeManagerInterface $entityTypeManager, UuidInterface $uuidService, ConfigFactoryInterface $configService, QueueFactory $queueService) {
+    $this->entityTypeManager = $entityTypeManager;
+    $this->uuidService = $uuidService;
+    $this->configService = $configService;
+    $this->queueService = $queueService;
+  }
+
+  /**
+   * Replaces some dataset property values with references.
+   *
+   * @param \stdClass $data
+   *   Dataset json object.
+   *
+   * @return \stdClass
+   *   Json object modified with references to some of its properties' values.
+   */
+  public function reference(stdClass $data) {
+    // Cycle through the dataset properties we seek to reference.
+    foreach ($this->getPropertyList() as $property_id) {
+      if (isset($data->{$property_id})) {
+        $data->{$property_id} = $this->referenceProperty($property_id, $data->{$property_id});
+      }
+    }
+    return $data;
+  }
+
+  /**
+   * References a dataset property's value, general case.
+   *
+   * @param string $property_id
+   *   The dataset property id.
+   * @param mixed $data
+   *   Single value or array of values to be referenced.
+   *
+   * @return string|array
+   *   Single reference, or an array of references.
+   */
+  protected function referenceProperty(string $property_id, $data) {
+    if (is_array($data)) {
+      return $this->referenceMultiple($property_id, $data);
+    }
+    else {
+      // Object or string.
+      return $this->referenceSingle($property_id, $data);
+    }
+  }
+
+  /**
+   * References a dataset property's value, array case.
+   *
+   * @param string $property_id
+   *   The dataset property id.
+   * @param array $values
+   *   The array of values to be referenced.
+   *
+   * @return array
+   *   The array of uuid references.
+   */
+  protected function referenceMultiple(string $property_id, array $values) : array {
+    $result = [];
+    foreach ($values as $value) {
+      $result[] = $this->referenceSingle($property_id, $value);
+    }
+    return $result;
+  }
+
+  /**
+   * References a dataset property's value, string or object case.
+   *
+   * @param string $property_id
+   *   The dataset property id.
+   * @param string|object $value
+   *   The value to be referenced.
+   *
+   * @return string
+   *   The Uuid reference, or unchanged value.
+   */
+  protected function referenceSingle(string $property_id, $value) {
+    $uuid = $this->checkExistingReference($property_id, $value);
+    if (!$uuid) {
+      $uuid = $this->createPropertyReference($property_id, $value);
+    }
+    if ($uuid) {
+      return $uuid;
+    }
+    else {
+      // In the unlikely case we neither found an existing reference nor could
+      // create a new reference, return the unchanged value.
+      return $value;
+    }
+  }
+
+  /**
+   * Checks for an existing value reference for that property id.
+   *
+   * @param string $property_id
+   *   The dataset property id.
+   * @param $data
+   *   The property's value used to find an existing reference.
+   *
+   * @return string|null
+   *   The existing reference's uuid, or null if not found.
+   */
+  protected function checkExistingReference(string $property_id, $data) {
+    $nodes = $this->entityTypeManager
+      ->getStorage('node')
+      ->loadByProperties([
+        'field_data_type' => $property_id,
+        'title' => md5(json_encode($data)),
+      ]);
+
+    if ($node = reset($nodes)) {
+      return $node->uuid->value;
+    }
+    return NULL;
+  }
+
+  /**
+   * Creates a new value reference for that property id in a data node.
+   *
+   * @param string $property_id
+   *   The dataset property id.
+   * @param mixed $value
+   *   The property's value.
+   *
+   * @return string|null
+   *   The new reference's uuid, or null.
+   */
+  protected function createPropertyReference(string $property_id, $value) {
+    // Create json metadata for the reference.
+    $data = new stdClass();
+    $data->identifier = $this->uuidService->generate();
+    $data->data = $value;
+
+    // Create node to store this reference.
+    $node = $this->entityTypeManager
+      ->getStorage('node')
+      ->create([
+        'title' => md5(json_encode($value)),
+        'type' => 'data',
+        'uuid' => $data->identifier,
+        'field_data_type' => $property_id,
+        'field_json_metadata' => json_encode($data),
+      ]);
+    $node->save();
+
+    return $node->uuid();
+  }
+
+  /**
+   * Replaces value references in a dataset with with their actual values.
+   *
+   * @param \stdClass $data
+   *   The json metadata object.
+   *
+   * @return mixed
+   *   Modified json metadata object.
+   */
+  public function dereference(stdClass $data) {
+    // Cycle through the dataset properties we seek to dereference.
+    foreach ($this->getPropertyList() as $property_id) {
+      if (isset($data->{$property_id})) {
+        $data->{$property_id} = $this->dereferenceProperty($property_id, $data->{$property_id});
+      }
+    }
+    return $data;
+  }
+
+  /**
+   * Replaces a property reference with its actual value, general case.
+   *
+   * @param string $property_id
+   *   The dataset property id.
+   * @param string|array $uuids
+   *   A single reference uuid string, or an array reference uuids.
+   *
+   * @return string|array
+   *   An array of dereferenced values, or a single one.
+   */
+  protected function dereferenceProperty(string $property_id, $data) {
+    if (is_array($data)) {
+      return $this->dereferenceMultiple($property_id, $data);
+    }
+    else {
+      return $this->dereferenceSingle($property_id, $data);
+    }
+  }
+
+  /**
+   * Replaces a property reference with its actual value, array case.
+   *
+   * @param string $property_id
+   *   A dataset property id.
+   * @param array $uuids
+   *   An array of reference uuids.
+   *
+   * @return array
+   *   An array of dereferenced values.
+   */
+  protected function dereferenceMultiple(string $property_id, array $uuids) : array {
+    $result = [];
+    foreach ($uuids as $uuid) {
+      $result[] = $this->dereferenceSingle($property_id, $uuid);
+    }
+    return $result;
+  }
+
+  /**
+   * Replaces a property reference with its actual value, string or object case.
+   *
+   * @param string $property_id
+   *   The dataset property id.
+   * @param string $str
+   *   Either a uuid or an actual json value.
+   *
+   * @return string
+   *   The data from this reference.
+   */
+  protected function dereferenceSingle(string $property_id, string $uuid) {
+    $nodes = $this->entityTypeManager
+      ->getStorage('node')
+      ->loadByProperties([
+        'field_data_type' => $property_id,
+        'uuid' => $uuid,
+      ]);
+    if ($node = reset($nodes)) {
+      if (isset($node->field_json_metadata->value)) {
+        $metadata = json_decode($node->field_json_metadata->value);
+        return $metadata->data;
+      }
+    }
+    // If str was not found, it's unlikely it was a uuid to begin with. It was
+    // most likely never referenced to begin with, so return unchanged.
+    return $uuid;
+  }
+
+  /**
+   * Check for orphan references when a dataset is being deleted.
+   *
+   * @param \stdClass $data
+   *   Dataset to be deleted.
+   */
+  public function processReferencesInDeletedDataset(stdClass $data) {
+    // Cycle through the dataset properties we seek to reference.
+    foreach ($this->getPropertyList() as $property_id) {
+      if (isset($data->{$property_id})) {
+        $this->processReferencesInDeletedProperty($property_id, $data->{$property_id});
+      }
+    }
+  }
+
+  /**
+   *
+   */
+  protected function processReferencesInDeletedProperty($property_id, $uuids) {
+    // Treat single uuid as an array of one uuid.
+    if (!is_array($uuids)) {
+      $uuids = [$uuids];
+    }
+    foreach ($uuids as $uuid) {
+      $this->queueReferenceForRemoval($property_id, $uuid);
+    }
+  }
+
+  /**
+   * @param $property_id
+   * @param $uuid
+   *
+   * @codeCoverageIgnore since no logic, single call to queue worker.
+   */
+  protected function queueReferenceForRemoval($property_id, $uuid) {
+    $this->queueService->get('orphan_reference_processor')
+      ->createItem([
+        $property_id,
+        $uuid,
+      ]);
+  }
+
+  /**
+   *
+   */
+  public function processReferencesInUpdatedDataset(stdClass $old_dataset, stdClass $new_dataset) {
+    // Cycle through the dataset properties being referenced, check for orphans.
+    foreach ($this->getPropertyList() as $property_id) {
+      if (!isset($old_dataset->{$property_id})) {
+        // The old dataset had no value for this property, thus no references
+        // could be deleted. Safe to skip checking for orphan reference.
+        continue;
+      }
+      if (!isset($new_dataset->{$property_id})) {
+        $new_dataset->{$property_id} = $this->emptyPropertyOfSameType($old_dataset->{$property_id});
+      }
+      $this->processReferencesInUpdatedProperty($property_id, $old_dataset->{$property_id}, $new_dataset->{$property_id});
+    }
+  }
+
+  /**
+   *
+   */
+  protected function processReferencesInUpdatedProperty($property_id, $old_value, $new_value) {
+    if (!is_array($old_value)) {
+      $old_value = [$old_value];
+      $new_value = [$new_value];
+    }
+    foreach (array_diff($old_value, $new_value) as $removed_reference) {
+      $this->queueReferenceForRemoval($property_id, $removed_reference);
+    }
+  }
+
+  /**
+   * @param $data
+   *
+   * @return array|string
+   */
+  protected function emptyPropertyOfSameType($data) {
+    if (is_array($data)) {
+      return [];
+    }
+    return "";
+  }
+
+  /**
+   * Get the list of dataset properties being referenced.
+   *
+   * @return array
+   *   List of dataset properties.
+   *
+   * @Todo: consolidate with dkan_api RouteProvider's getPropertyList.
+   */
+  protected function getPropertyList() : array {
+    $list = $this->configService->get('dkan_data.settings')->get('property_list');
+    if ($list) {
+      // Trim and split list on newlines whether Windows, MacOS or Linux.
+      return preg_split(
+        '/\s*\r\n\s*|\s*\r\s*|\s*\n\s*/',
+        trim($list),
+        -1,
+        PREG_SPLIT_NO_EMPTY
+      );
+    }
+    else {
+      return [];
+    }
+  }
+
+}
diff --git a/modules/custom/dkan_data/tests/src/Unit/CofigurationOverriderTest.php b/modules/custom/dkan_data/tests/src/Unit/ConfigurationOverriderTest.php
similarity index 100%
rename from modules/custom/dkan_data/tests/src/Unit/CofigurationOverriderTest.php
rename to modules/custom/dkan_data/tests/src/Unit/ConfigurationOverriderTest.php
diff --git a/modules/custom/dkan_data/tests/src/Unit/ValueReferencerTest.php b/modules/custom/dkan_data/tests/src/Unit/ValueReferencerTest.php
new file mode 100644
index 0000000000..cfd805686e
--- /dev/null
+++ b/modules/custom/dkan_data/tests/src/Unit/ValueReferencerTest.php
@@ -0,0 +1,827 @@
+<?php
+
+namespace Drupal\Tests\dkan_data\Unit;
+
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Config\ImmutableConfig;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\dkan_common\Tests\DkanTestBase;
+use Drupal\dkan_data\ValueReferencer;
+use Drupal\Component\Uuid\UuidInterface;
+use Drupal\Core\Queue\QueueFactory;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\node\NodeInterface;
+use Drupal\Core\Entity\EntityInterface;
+use stdClass;
+
+/**
+ * Tests Drupal\dkan_dataValueReferencer.
+ *
+ * @coversDefaultClass \Drupal\dkan_data\ValueReferencer
+ * @group dkan_data
+ */
+class ValueReferencerTest extends DkanTestBase {
+
+  /**
+   * Tests the constructor.
+   */
+  public function testConstruct() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods(NULL)
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $mockEntityTypeManager = $this->createMock(EntityTypeManagerInterface::class);
+    $mockUuidInterface     = $this->createMock(UuidInterface::class);
+    $mockConfigInterface   = $this->createMock(ConfigFactoryInterface::class);
+    $mockQueueFactory      = $this->createMock(QueueFactory::class);
+
+    // Assert.
+    $mock->__construct($mockEntityTypeManager, $mockUuidInterface, $mockConfigInterface, $mockQueueFactory);
+
+    $this->assertSame($mockEntityTypeManager, $this->readAttribute($mock, 'entityTypeManager'));
+    $this->assertSame($mockUuidInterface, $this->readAttribute($mock, 'uuidService'));
+    $this->assertSame($mockConfigInterface, $this->readAttribute($mock, 'configService'));
+    $this->assertSame($mockQueueFactory, $this->readAttribute($mock, 'queueService'));
+  }
+
+  /**
+   * Provides data for testing checkExistingReference function.
+   */
+  public function dataTestCheckExistingReference() {
+    $mockNode = $this->createMock(NodeInterface::class);
+    $expected = uniqid('a-uuid');
+    $mockNode->uuid = (object) ['value' => $expected];
+
+    return [
+      ['theme', 'Topic One', [$mockNode], $expected],
+      ['barfoo', '', [], NULL],
+    ];
+  }
+
+  /**
+   * Tests the checkExistingReference function.
+   *
+   * @param string $property_id
+   *   The property name.
+   * @param mixed $data
+   *   The json value of the property.
+   * @param array $nodes
+   *   Array of node objects with uuid->value properties.
+   * @param mixed $expected
+   *   Expected result.
+   *
+   * @dataProvider dataTestCheckExistingReference
+   */
+  public function testCheckExistingReference($property_id, $data, array $nodes, $expected) {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods(NULL)
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $mockEntityTypeManager = $this->getMockBuilder(EntityTypeManagerInterface::class)
+      ->setMethods([
+        'getStorage',
+      ])
+      ->getMockForAbstractClass();
+
+    $this->writeProtectedProperty($mock, 'entityTypeManager', $mockEntityTypeManager);
+
+    $mockNodeStorage = $this->getMockBuilder(EntityStorageInterface::class)
+      ->setMethods([
+        'loadByProperties',
+      ])
+      ->getMockForAbstractClass();
+
+    // Expect.
+    $mockEntityTypeManager->expects($this->once())
+      ->method('getStorage')
+      ->with('node')
+      ->willReturn($mockNodeStorage);
+
+    $mockNodeStorage->expects($this->once())
+      ->method('loadByProperties')
+      ->with([
+        'field_data_type' => $property_id,
+        'title'           => md5(json_encode($data)),
+      ])
+      ->willReturn($nodes);
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'checkExistingReference', $property_id, $data);
+    $this->assertEquals($expected, $actual);
+  }
+
+  /**
+   * Tests the createPropertyReference function.
+   */
+  public function testCreatePropertyReference() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->disableOriginalConstructor()
+      ->setMethods(NULL)
+      ->getMock();
+
+    $mockUuidInterface = $this->getMockBuilder(UuidInterface::class)
+      ->disableOriginalConstructor()
+      ->setMethods([
+        'generate',
+      ])
+      ->getMockForAbstractClass();
+    $this->writeProtectedProperty($mock, 'uuidService', $mockUuidInterface);
+
+    $mockEntityTypeManager = $this->getMockBuilder(EntityTypeManagerInterface::class)
+      ->setMethods([
+        'getStorage',
+      ])
+      ->getMockForAbstractClass();
+    $this->writeProtectedProperty($mock, 'entityTypeManager', $mockEntityTypeManager);
+
+    $mockNodeStorage = $this->getMockBuilder(EntityStorageInterface::class)
+      ->setMethods([
+        'create',
+      ])
+      ->getMockForAbstractClass();
+
+    $mockEntityInterface = $this->getMockBuilder(EntityInterface::class)
+      ->setMethods([
+        'save',
+        'uuid',
+      ])
+      ->getMockForAbstractClass();
+
+    $property_id = uniqid('some-property-');
+    $value = uniqid('some-value-');
+    $uuid = uniqid('some-uuid-');
+    $data = new stdClass();
+    $data->identifier = $uuid;
+    $data->data = $value;
+
+    // Expect.
+    $mockUuidInterface->expects($this->once())
+      ->method('generate')
+      ->willReturn($uuid);
+    $mockEntityTypeManager->expects($this->once())
+      ->method('getStorage')
+      ->with('node')
+      ->willReturn($mockNodeStorage);
+    $mockNodeStorage->expects($this->once())
+      ->method('create')
+      ->with([
+        'title' => md5(json_encode($value)),
+        'type' => 'data',
+        'uuid' => $uuid,
+        'field_data_type' => $property_id,
+        'field_json_metadata' => json_encode($data),
+      ])
+      ->willReturn($mockEntityInterface);
+    $mockEntityInterface->expects($this->once())
+      ->method('save')
+      ->willReturn(1);
+    $mockEntityInterface->expects($this->once())
+      ->method('uuid')
+      ->willReturn($uuid);
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'createPropertyReference', $property_id, $value);
+    $this->assertEquals($uuid, $actual);
+  }
+
+  /**
+   * Provides data for testing function referenceSingle.
+   */
+  public function dataTestReferenceSingle() {
+    $property_id = 'some-property';
+    $value = 'some-value';
+    $uuid = uniqid('existing-reference-uuid-');
+
+    return [
+      'found an existing reference' => [
+        $property_id, $value, $uuid, NULL, $uuid,
+      ],
+      'created a new reference' => [
+        $property_id, $value, NULL, $uuid, $uuid,
+      ],
+      'neither found existing nor created new reference' => [
+        $property_id, $value, NULL, NULL, $value,
+      ],
+    ];
+  }
+
+  /**
+   * Tests function referenceSingle with existing value reference.
+   *
+   * @param string $property_id
+   *   The property name.
+   * @param string $value
+   *   The json value of the property.
+   * @param string|null $checkExisting
+   *   The expected value of checkExistingReference.
+   * @param string|null $createProperty
+   *   The expected value of createPropertyReference.
+   * @param string $expected
+   *   The expected return value of referenceSingle.
+   *
+   * @dataProvider dataTestReferenceSingle
+   */
+  public function testReferenceSingle(string $property_id, $value, $checkExisting, $createProperty, $expected) {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->disableOriginalConstructor()
+      ->setMethods(['checkExistingReference', 'createPropertyReference'])
+      ->getMock();
+
+    // Expect.
+    $mock->expects($this->exactly(1))
+      ->method('checkExistingReference')
+      ->with($property_id, $value)
+      ->willReturn($checkExisting);
+    $mock->expects($this->any())
+      ->method('createPropertyReference')
+      ->with($property_id, $value)
+      ->willReturn($createProperty);
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'referenceSingle', $property_id, $value);
+    $this->assertEquals($expected, $actual);
+  }
+
+  /**
+   * Test function referenceMultiple.
+   */
+  public function testReferenceMultiple() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->disableOriginalConstructor()
+      ->setMethods(['referenceSingle'])
+      ->getMock();
+
+    $property_id = 'theme';
+    $values = [
+      "Topic One",
+      "Topic Two",
+      "Topic Three",
+    ];
+    $referenceSingle = [
+      "uuid-one",
+      "uuid-two",
+      "uuid-three",
+    ];
+
+    // Expect.
+    $mock->expects($this->exactly(3))
+      ->method('referenceSingle')
+      ->withConsecutive(
+        [$property_id, $values[0]],
+        [$property_id, $values[1]],
+        [$property_id, $values[2]]
+      )
+      ->willReturnOnConsecutiveCalls(
+        $referenceSingle[0],
+        $referenceSingle[1],
+        $referenceSingle[2]
+      );
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'referenceMultiple', $property_id, $values);
+    $this->assertEquals($referenceSingle, $actual);
+  }
+
+  /**
+   * Provides data for testReferenceProperty.
+   */
+  public function dataTestReferenceProperty() {
+    $property_id = 'some-property';
+    $uuid = uniqid('existing-reference-uuid-');
+
+    return [
+      'data is a string' => [
+        $property_id,
+        'some-value',
+        NULL,
+        $uuid,
+        $uuid,
+      ],
+      'data is an object' => [
+        $property_id,
+        (object) ['some' => 'object'],
+        NULL,
+        $uuid,
+        $uuid,
+      ],
+      'data is an array' => [
+        $property_id,
+        ['some value'],
+        [$uuid],
+        NULL,
+        [$uuid],
+      ],
+    ];
+  }
+
+  /**
+   * Tests function referenceProperty.
+   *
+   * @param string $property_id
+   *   The property name.
+   * @param string|array $data
+   *   The json value of the property.
+   * @param string|null $refMultiple
+   *   The expected value of referenceMultiple.
+   * @param string|null $refSingle
+   *   The expected value of referenceSingle.
+   * @param string|array $expected
+   *   The expected return value of referenceProperty.
+   *
+   * @dataProvider dataTestReferenceProperty
+   */
+  public function testReferenceProperty(string $property_id, $data, $refMultiple, $refSingle, $expected) {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->disableOriginalConstructor()
+      ->setMethods(['referenceMultiple', 'referenceSingle'])
+      ->getMock();
+
+    // Expect.
+    $mock->expects($this->any())
+      ->method('referenceMultiple')
+      ->with($property_id, $data)
+      ->willReturn($refMultiple);
+    $mock->expects($this->any())
+      ->method('referenceSingle')
+      ->with($property_id, $data)
+      ->willReturn($refSingle);
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'referenceProperty', $property_id, $data);
+    $this->assertEquals($expected, $actual);
+  }
+
+  /**
+   * Tests function getPropertyList.
+   */
+  public function testGetPropertyList() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods(NULL)
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $mockConfigService = $this->getMockBuilder(ConfigFactoryInterface::class)
+      ->setMethods(['get'])
+      ->getMockForAbstractClass();
+
+    $this->writeProtectedProperty($mock, 'configService', $mockConfigService);
+
+    $mockImmutableConfig = $this->getMockBuilder(ImmutableConfig::class)
+      ->setMethods(['get'])
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $this->writeProtectedProperty($mock, 'configService', $mockConfigService);
+
+    $list = "theme
+    some property     
+    yet another property
+    
+    ";
+    $expected = [
+      'theme',
+      'some property',
+      'yet another property',
+    ];
+
+    // Expect.
+    $mockConfigService->expects($this->once())
+      ->method('get')
+      ->with('dkan_data.settings')
+      ->willReturn($mockImmutableConfig);
+
+    $mockImmutableConfig->expects($this->once())
+      ->method('get')
+      ->with('property_list')
+      ->willReturn($list);
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'getPropertyList');
+    $this->assertEquals($expected, $actual);
+  }
+
+  /**
+   * Tests function reference.
+   */
+  public function testReference() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods(['getPropertyList', 'referenceProperty'])
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $properties_list = [
+      'property to be referenced',
+      'another to reference',
+    ];
+    $data = (object) [
+      'property to be referenced' => 'Some value',
+      'another to reference' => 'Yet another value',
+      'other property' => 'Some other value',
+    ];
+    $uuid1 = uniqid('property1-reference-');
+    $uuid2 = uniqid('property2-reference-');
+    $expected = (object) [
+      'property to be referenced' => $uuid1,
+      'another to reference' => $uuid2,
+      'other property' => 'Some other value',
+    ];
+
+    // Expect.
+    $mock->expects($this->once())
+      ->method('getPropertyList')
+      ->willReturn($properties_list);
+    $mock->expects($this->exactly(2))
+      ->method('referenceProperty')
+      ->withConsecutive(
+        [$properties_list[0], $data->{$properties_list[0]}],
+        [$properties_list[1], $data->{$properties_list[1]}]
+      )
+      ->willReturnOnConsecutiveCalls(
+        $uuid1,
+        $uuid2
+      );
+
+    // Assert.
+    $this->assertEquals($expected, $mock->reference($data));
+  }
+
+  /**
+   * Provides data for testDereferenceProperty.
+   */
+  public function dataTestDereferenceProperty() {
+    $property_id = 'some-property';
+    $uuid1 = uniqid('property-one-uuid-');
+    $value1_retrieved = uniqid('value-one-retrieved-');
+    $uuid2 = uniqid('property-two-uuid-');
+    $value2_retrieved = uniqid('value-two-retrieved-');
+
+    return [
+      'dereferencing a single uuid' => [
+        $property_id,
+        $uuid1,
+        NULL,
+        $value1_retrieved,
+        $value1_retrieved,
+      ],
+      'dereferencing an array of uuid' => [
+        $property_id,
+        [$uuid1, $uuid2],
+        [$value1_retrieved, $value2_retrieved],
+        NULL,
+        [$value1_retrieved, $value2_retrieved],
+      ],
+    ];
+  }
+
+  /**
+   * Tests function dereferenceProperty.
+   *
+   * @param string $property_id
+   *   The property name.
+   * @param string|array $uuids
+   *   One or more uuids from the property's value.
+   * @param string $deRefMultiple
+   *   The expected value of dereferenceMultiple.
+   * @param string $deRefSingle
+   *   The expected value of dereferenceSingle.
+   * @param string|array $expected
+   *   The expected return value of dereferenceProperty.
+   *
+   * @dataProvider dataTestDereferenceProperty
+   */
+  public function testDereferenceProperty(string $property_id, $uuids, $deRefMultiple, $deRefSingle, $expected) {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->disableOriginalConstructor()
+      ->setMethods(['dereferenceMultiple', 'dereferenceSingle'])
+      ->getMock();
+
+    // Expect.
+    $mock->expects($this->any())
+      ->method('dereferenceMultiple')
+      ->with($property_id, $uuids)
+      ->willReturn($deRefMultiple);
+    $mock->expects($this->any())
+      ->method('dereferenceSingle')
+      ->with($property_id, $uuids)
+      ->willReturn($deRefSingle);
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'dereferenceProperty', $property_id, $uuids);
+    $this->assertEquals($expected, $actual);
+  }
+
+  /**
+   * Tests function dereferenceMultiple.
+   */
+  public function testDereferenceMultiple() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->disableOriginalConstructor()
+      ->setMethods(['dereferenceSingle'])
+      ->getMock();
+
+    $property_id = 'someProperty';
+    $uuids = [
+      uniqid('property-uuid1-'),
+      uniqid('property-uuid2-'),
+      'Third, non-referenced property value',
+    ];
+    $dereferenceSingle = [
+      "First property value",
+      "Second property value",
+      "Third, non-referenced property value",
+    ];
+
+    // Expect.
+    $mock->expects($this->exactly(3))
+      ->method('dereferenceSingle')
+      ->withConsecutive(
+        [$property_id, $uuids[0]],
+        [$property_id, $uuids[1]],
+        [$property_id, $uuids[2]]
+      )
+      ->willReturnOnConsecutiveCalls(
+        $dereferenceSingle[0],
+        $dereferenceSingle[1],
+        $dereferenceSingle[2]
+      );
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'dereferenceMultiple', $property_id, $uuids);
+    $this->assertEquals($dereferenceSingle, $actual);
+  }
+
+  /**
+   * Provides data for testing checkExistingReference function.
+   */
+  public function datatestDereferenceSingle() {
+    $mockNode = $this->createMock(NodeInterface::class);
+    $uuid = uniqid('some-property-uuid-');
+    $expected = "Some Property Value";
+    $mockNode->field_json_metadata = (object) ['value' => '{"data": "Some Property Value"}'];
+
+    return [
+      ['someProperty', $uuid, [$mockNode], $expected],
+      ['someProperty', $uuid, [], $uuid],
+    ];
+  }
+
+  /**
+   * Tests function dereferenceSingle.
+   *
+   * @param string $property_id
+   *   The property name.
+   * @param string $uuid
+   *   The uuid.
+   * @param array $nodes
+   *   The expected $nodes array internally.
+   * @param string $expected
+   *   The expected return value of dereferenceSingle.
+   *
+   * @dataProvider dataTestDereferenceSingle
+   */
+  public function testDereferenceSingle(string $property_id, string $uuid, array $nodes, $expected) {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods(NULL)
+      ->disableOriginalConstructor()
+      ->getMock();
+    $mockEntityTypeManager = $this->getMockBuilder(EntityTypeManagerInterface::class)
+      ->setMethods([
+        'getStorage',
+      ])
+      ->getMockForAbstractClass();
+    $this->writeProtectedProperty($mock, 'entityTypeManager', $mockEntityTypeManager);
+    $mockNodeStorage = $this->getMockBuilder(EntityStorageInterface::class)
+      ->setMethods([
+        'loadByProperties',
+      ])
+      ->getMockForAbstractClass();
+
+    // Expect.
+    $mockEntityTypeManager->expects($this->once())
+      ->method('getStorage')
+      ->with('node')
+      ->willReturn($mockNodeStorage);
+    $mockNodeStorage->expects($this->once())
+      ->method('loadByProperties')
+      ->with([
+        'field_data_type' => $property_id,
+        'uuid'           => $uuid,
+      ])
+      ->willReturn($nodes);
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'dereferenceSingle', $property_id, $uuid);
+    $this->assertEquals($expected, $actual);
+  }
+
+  /**
+   * Tests function dereference.
+   */
+  public function testDereference() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods(['getPropertyList', 'dereferenceProperty'])
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $properties_list = [
+      'property to be dereferenced',
+      'another to dereference',
+    ];
+    $uuid1 = uniqid('uuid1-');
+    $uuid2 = uniqid('uuid2-');
+    $data = (object) [
+      'property to be dereferenced' => $uuid1,
+      'another to dereference' => $uuid2,
+      'other property' => 'Some other value',
+    ];
+    $expected = (object) [
+      'property to be dereferenced' => 'Some value',
+      'another to dereference' => 'Yet another value',
+      'other property' => 'Some other value',
+    ];
+
+    // Expect.
+    $mock->expects($this->once())
+      ->method('getPropertyList')
+      ->willReturn($properties_list);
+    $mock->expects($this->exactly(2))
+      ->method('dereferenceProperty')
+      ->withConsecutive(
+        [$properties_list[0], $uuid1],
+        [$properties_list[1], $uuid2]
+      )
+      ->willReturnOnConsecutiveCalls(
+        'Some value',
+        'Yet another value'
+      );
+
+    // Assert.
+    $this->assertEquals($expected, $mock->dereference($data));
+  }
+
+  /**
+   * Provides data to test emptyPropertyOfSameType.
+   */
+  public function dataEmptyPropertyOfSameType() {
+    return [
+      [
+        "some string", "",
+      ],
+      [
+        ['some', 'array'], [],
+      ],
+    ];
+  }
+
+  /**
+   * Tests the emptyPropertyOfSameType function.
+   *
+   * @dataProvider dataEmptyPropertyOfSameType
+   */
+  public function testEmptyPropertyOfSameType($data, $expected) {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->disableOriginalConstructor()
+      ->setMethods(NULL)
+      ->getMock();
+
+    // Assert.
+    $actual = $this->invokeProtectedMethod($mock, 'emptyPropertyOfSameType', $data);
+    $this->assertEquals($expected, $actual);
+  }
+
+  /**
+   * Tests function processReferencesInUpdatedProperty.
+   */
+  public function testProcessReferencesInUpdatedProperty() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods(['queueReferenceForRemoval'])
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $property_id = 'someProperty';
+    $old = uniqid('some-uuid-old-');
+    $new = uniqid('some-uuid-new-');
+
+    $mock->expects($this->once())
+      ->method('queueReferenceForRemoval')
+      ->willReturn(NULL);
+
+    // Assert.
+    $this->invokeProtectedMethod($mock, 'processReferencesInUpdatedProperty', $property_id, $old, $new);
+  }
+
+  /**
+   * Tests function processReferencesInDeletedProperty.
+   */
+  public function testProcessReferencesInDeletedProperty() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods(['queueReferenceForRemoval'])
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $property_id = 'someProperty';
+    $old = uniqid('some-uuid-old-');
+
+    $mock->expects($this->once())
+      ->method('queueReferenceForRemoval')
+      ->willReturn(NULL);
+
+    // Assert.
+    $this->invokeProtectedMethod($mock, 'processReferencesInDeletedProperty', $property_id, $old);
+  }
+
+  /**
+   * Tests function processReferencesInDeletedDataset.
+   */
+  public function testProcessReferencesInDeletedDataset() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods(['getPropertyList', 'processReferencesInDeletedProperty'])
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $properties_list = [
+      'property to be dereferenced',
+      'another to dereference',
+    ];
+    $uuid1 = uniqid('uuid1-');
+    $uuid2 = uniqid('uuid2-');
+    $data = (object) [
+      'property to be dereferenced' => $uuid1,
+      'another to dereference' => $uuid2,
+      'other property' => 'Some other value',
+    ];
+
+    // Expect.
+    $mock->expects($this->once())
+      ->method('getPropertyList')
+      ->willReturn($properties_list);
+    $mock->expects($this->exactly(2))
+      ->method('processReferencesInDeletedProperty')
+      ->willReturn(NULL);
+
+    // Assert.
+    $this->invokeProtectedMethod($mock, 'processReferencesInDeletedDataset', $data);
+  }
+
+  /**
+   * Tests function processReferencesInUpdatedDataset.
+   */
+  public function testProcessReferencesInUpdatedDataset() {
+    // Setup.
+    $mock = $this->getMockBuilder(ValueReferencer::class)
+      ->setMethods([
+        'getPropertyList',
+        'emptyPropertyOfSameType',
+        'processReferencesInUpdatedProperty',
+      ])
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $properties_list = [
+      'property only in old',
+      'property only in new',
+    ];
+    $old_uuid = uniqid('uuid-old-');
+    $new_uuid = uniqid('uuid-new-');
+    $old = (object) [
+      'property only in old' => $old_uuid,
+    ];
+    $new = (object) [
+      'property only in new' => $new_uuid,
+    ];
+
+    // Expect.
+    $mock->expects($this->once())
+      ->method('getPropertyList')
+      ->willReturn($properties_list);
+    $mock->expects($this->once())
+      ->method('processReferencesInUpdatedProperty')
+      ->willReturn(NULL);
+    $mock->expects($this->once())
+      ->method('emptyPropertyOfSameType')
+      ->with()
+      ->willReturn(NULL);
+
+    // Assert.
+    $this->invokeProtectedMethod($mock, 'processReferencesInUpdatedDataset', $old, $new);
+  }
+
+}
diff --git a/modules/custom/dkan_harvest/src/Reverter.php b/modules/custom/dkan_harvest/src/Reverter.php
index 77eb070451..fe560d2282 100644
--- a/modules/custom/dkan_harvest/src/Reverter.php
+++ b/modules/custom/dkan_harvest/src/Reverter.php
@@ -41,6 +41,7 @@ public function run() {
     /** @var \Drupal\dkan_api\Storage\DrupalNodeDataset $datastore_storage */
     // Cannot use DI here since this class is called by a non drupal package.
     $datastore_storage = \Drupal::service('dkan_api.storage.drupal_node_dataset');
+    $datastore_storage->setSchema('dataset');
 
     $counter = 0;
     foreach ($uuids as $uuid) {
diff --git a/modules/custom/interra_api/src/Controller/ApiController.php b/modules/custom/interra_api/src/Controller/ApiController.php
index 5f8b1fb913..a997ed69c3 100644
--- a/modules/custom/interra_api/src/Controller/ApiController.php
+++ b/modules/custom/interra_api/src/Controller/ApiController.php
@@ -87,6 +87,7 @@ public function collection($collection) {
 
       /** @var \Drupal\dkan_api\Storage\DrupalNodeDataset $storage */
       $storage = \Drupal::service('dkan_api.storage.drupal_node_dataset');
+      $storage->setSchema('dataset');
       $data = $storage->retrieveAll();
 
       if ($collection == "dataset") {
@@ -172,6 +173,8 @@ protected function docDatasetHandler($doc) {
     $uuid = str_replace(".json", "", $doc);
     /** @var \Drupal\dkan_api\Storage\DrupalNodeDataset $storage */
     $storage = \Drupal::service('dkan_api.storage.drupal_node_dataset');
+    $storage->setSchema('dataset');
+
     /** @var \Drupal\interra_api\Service\DatasetModifier $datasetModifuer */
     $datasetModifier = \Drupal::service('interra_api.service.dataset_modifier');
     $data            = $storage->retrieve($uuid);
diff --git a/modules/custom/interra_api/tests/src/Unit/Controller/ApiControllerTest.php b/modules/custom/interra_api/tests/src/Unit/Controller/ApiControllerTest.php
index 8063f4e2ee..0984415398 100644
--- a/modules/custom/interra_api/tests/src/Unit/Controller/ApiControllerTest.php
+++ b/modules/custom/interra_api/tests/src/Unit/Controller/ApiControllerTest.php
@@ -378,6 +378,7 @@ public function testDocDatasetHandler() {
 
       $mockDrupalNodeDataset = $this->getMockBuilder(Storage::class)
         ->setMethods([
+          'setSchema',
         'retrieve',
         ])
         ->getMockForAbstractClass();