Data modifier plugin and behavior enhancements for non-public datasets (

#290)

modules/custom/dkan_common/dkan_common.services.yml

@@ -1,5 +1,8 @@
 services:
-    dkan.factory:
-        class: Drupal\dkan_common\Service\Factory
-    dkan.json_util:
-        class: Drupal\dkan_common\Service\JsonUtil
+  dkan.factory:
+    class: Drupal\dkan_common\Service\Factory
+  dkan.json_util:
+    class: Drupal\dkan_common\Service\JsonUtil
+  plugin.manager.dkan_common.data_modifier:
+    class: \Drupal\dkan_common\Plugin\DataModifierManager
+    parent: default_plugin_manager

modules/custom/dkan_common/src/Annotation/DataModifier.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Drupal\dkan_common\Annotation;
+
+use Drupal\Component\Annotation\Plugin;
+
+/**
+ * Annotation for data modifier plugins.
+ *
+ * @see plugin_api
+ *
+ * @Annotation
+ */
+class DataModifier extends Plugin {
+
+  /**
+   * The plugin ID.
+   *
+   * @var string
+   */
+  public $id;
+
+  /**
+   * The label of the plugin.
+   *
+   * @var \Drupal\Core\Annotation\Translation
+   *
+   * @ingroup plugin_translatable
+   */
+  public $label;
+
+  /**
+   * Communicate the plugin's effect on the modified data.
+   *
+   * @var \Drupal\Core\Annotation\Translation
+   *
+   * @ingroup plugin_translatable
+   */
+  public $result;
+
+  /**
+   * HTTP code to include in response when modification has occured.
+   *
+   * @var int
+   */
+  public $resultCode;
+
+}

modules/custom/dkan_common/src/DataModifierPluginTrait.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Drupal\dkan_common;
+
+/**
+ * Provides common functionality for alls data modifier plugins.
+ */
+trait DataModifierPluginTrait {
+
+  /**
+   * Data modifier plugin manager service.
+   *
+   * @var \Drupal\dkan_common\Plugin\DataModifierManager
+   */
+  private $pluginManager;
+
+  /**
+   * Instances of discovered data modifier plugins.
+   *
+   * @var array
+   */
+  private $plugins = [];
+
+  /**
+   * Discover data modifier plugins.
+   *
+   * @return array
+   *   A list of discovered data modifier plugins.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\PluginException
+   */
+  private function discover() {
+    $plugins = [];
+    foreach ($this->pluginManager->getDefinitions() as $definition) {
+      $plugins[] = $this->pluginManager->createInstance($definition['id']);
+    }
+    return $plugins;
+  }
+
+}

modules/custom/dkan_common/src/Plugin/DataModifierBase.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace Drupal\dkan_common\Plugin;
+
+use Drupal\Component\Plugin\PluginBase;
+
+/**
+ * Defines an abstract base class for Data modifier plugins.
+ */
+abstract class DataModifierBase extends PluginBase implements DataModifierInterface {
+
+  /**
+   * Translate and render the result annotation.
+   *
+   * @return string
+   *   A message explaining the outcome.
+   */
+  public function message() : string {
+    return $this->getPluginDefinition()['result']->render();
+  }
+
+  /**
+   * Return the http code annotation.
+   *
+   * @return int
+   *   The http code.
+   */
+  public function httpCode() : int {
+    return (int) $this->getPluginDefinition()['code'];
+  }
+
+}

modules/custom/dkan_common/src/Plugin/DataModifierInterface.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace Drupal\dkan_common\Plugin;
+
+use Drupal\Component\Plugin\PluginInspectionInterface;
+
+/**
+ * Defines an interface for Data modifier plugins.
+ *
+ * Plugins of this type may have different conditions and outcomes, but all act
+ * on the following publicly accessible API endpoints:
+ *   - The metastore's GET collection and GET item
+ *   - The dataset-specific Api Docs
+ *   - The datastore's SQL query.
+ */
+interface DataModifierInterface extends PluginInspectionInterface {
+
+  /**
+   * Checks if the schema or data needs modifying.
+   *
+   * @param string $schema
+   *   The schema id.
+   * @param mixed $data
+   *   The data object, json string or identifier.
+   *
+   * @return bool
+   *   TRUE if the data requires modification, FALSE otherwise.
+   */
+  public function requiresModification(string $schema, $data);
+
+  /**
+   * Modify data.
+   *
+   * @param string $schema
+   *   The schema id.
+   * @param mixed $data
+   *   The object, json string or identifier whose data needs modifying.
+   *
+   * @return mixed
+   *   The modified data object, or FALSE.
+   */
+  public function modify(string $schema, $data);
+
+  /**
+   * Translate and render the result annotation.
+   *
+   * @return string
+   *   A message explaining the outcome.
+   */
+  public function message() : string;
+
+  /**
+   * Return the http code annotation.
+   *
+   * @return int
+   *   The http code.
+   */
+  public function httpCode() : int;
+
+}

modules/custom/dkan_common/src/Plugin/DataModifierManager.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace Drupal\dkan_common\Plugin;
+
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Plugin\DefaultPluginManager;
+
+/**
+ * Manages data modifier plugins.
+ */
+class DataModifierManager extends DefaultPluginManager {
+
+  /**
+   * Constructs a new DataModifierManager object.
+   *
+   * @param \Traversable $namespaces
+   *   An object that implements \Traversable which contains the root paths
+   *   keyed by the corresponding namespace to look for plugin implementations.
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
+   *   Cache backend instance to use.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler to invoke the alter hook with.
+   */
+  public function __construct(
+    \Traversable $namespaces,
+    CacheBackendInterface $cache_backend,
+    ModuleHandlerInterface $module_handler
+  ) {
+    parent::__construct(
+      'Plugin/DataModifier',
+      $namespaces,
+      $module_handler,
+      'Drupal\dkan_common\Plugin\DataModifierInterface',
+      'Drupal\dkan_common\Annotation\DataModifier'
+    );
+
+    $this->alterInfo('dkan_common_data_modifier_info');
+    $this->setCacheBackend($cache_backend, 'dkan_common_data_modifier_plugins');
+  }
+
+}

modules/custom/dkan_common/tests/src/Unit/Plugin/DataModifierManagerTest.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Drupal\dkan_common\Tests\Unit;
+
+use Drupal\Core\Cache\MemoryBackend;
+use Drupal\Core\Extension\ModuleHandler;
+use Drupal\dkan_common\Plugin\DataModifierManager;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Unit tests for class DataModifierManager.
+ *
+ * @package Drupal\dkan_common\Tests\Unit
+ */
+class DataModifierManagerTest extends TestCase {
+
+  /**
+   * Test constructor.
+   */
+  public function testDataModifierManager() {
+    $traversable = new \ArrayIterator();
+    $cache = new MemoryBackend();
+    $module = new ModuleHandler('blah', [], $cache);
+
+    $manager = new DataModifierManager($traversable, $cache, $module);
+    $this->assertTrue(is_object($manager));
+  }
+
+}

modules/custom/dkan_metastore/dkan_metastore.services.yml

@@ -4,6 +4,8 @@ services:
     arguments:
       - '@dkan_schema.schema_retriever'
       - '@dkan_metastore.sae_factory'
+    calls:
+      - [setDataModifierPlugins, ['@plugin.manager.dkan_common.data_modifier']]
   dkan_metastore.sae_factory:
     class: \Drupal\dkan_metastore\Factory\Sae
     arguments:

modules/custom/dkan_metastore/src/Service.php

@@ -2,6 +2,8 @@
 
 namespace Drupal\dkan_metastore;
 
+use Drupal\dkan_common\DataModifierPluginTrait;
+use Drupal\dkan_common\Plugin\DataModifierManager;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\dkan_metastore\Factory\Sae;
@@ -14,6 +16,7 @@
  * Service.
  */
 class Service implements ContainerInjectionInterface {
+  use DataModifierPluginTrait;
 
   /**
    * SAE Factory.
@@ -49,6 +52,17 @@ public function __construct(SchemaRetriever $schemaRetriever, Sae $saeFactory) {
     $this->saeFactory = $saeFactory;
   }
 
+  /**
+   * Setter to discover data modifier plugins.
+   *
+   * @param \Drupal\dkan_common\Plugin\DataModifierManager $pluginManager
+   *   Injected plugin manager.
+   */
+  public function setDataModifierPlugins(DataModifierManager $pluginManager) {
+    $this->pluginManager = $pluginManager;
+    $this->plugins = $this->discover();
+  }
+
   /**
    * Get schemas.
    */
@@ -86,7 +100,10 @@ public function getAll($schema_id): array {
 
     // $datasets is an array of JSON encoded string. Needs to be unflattened.
     $unflattened = array_map(
-      function ($json_string) {
+      function ($json_string) use ($schema_id) {
+        if (!empty($this->plugins)) {
+          $json_string = $this->modifyData($schema_id, $json_string);
+        }
         return json_decode($json_string);
       },
       $datasets
@@ -107,8 +124,35 @@ function ($json_string) {
    *   The json data.
    */
   public function get($schema_id, $identifier): string {
-    return $this->getEngine($schema_id)
+    $data = $this->getEngine($schema_id)
       ->get($identifier);
+    if (!empty($this->plugins)) {
+      $data = $this->modifyData($schema_id, $data);
+    }
+    return $data;
+  }
+
+  /**
+   * Provides data modifiers plugins an opportunity to act.
+   *
+   * @param string $schema_id
+   *   The {schema_id} slug from the HTTP request.
+   * @param string $data
+   *   The Json input.
+   *
+   * @return string
+   *   The Json, modified by each applicable discovered data modifier plugins.
+   */
+  private function modifyData(string $schema_id, string $data) {
+    $dataObj = json_decode($data);
+
+    foreach ($this->plugins as $plugin) {
+      if ($plugin->requiresModification($schema_id, $dataObj)) {
+        $dataObj = $plugin->modify($schema_id, $dataObj);
+      }
+    }
+
+    return json_encode($dataObj);
   }
 
   /**