Disallow some blocks

Closes #3460784

src/Plugin/UiPatterns/Source/BlockSource.php

@@ -9,6 +9,7 @@ use Drupal\Component\Utility\Html;
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Block\BlockManagerInterface;
 use Drupal\Core\Block\BlockPluginInterface;
+use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Entity\EntityDisplayBase;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Form\SubformState;
@@ -36,6 +37,8 @@ use Symfony\Component\DependencyInjection\ContainerInterface;
 )]
 class BlockSource extends SourcePluginBase {
 
+  const CACHE_KEY = 'ui_patterns_block_metadata';
+
   /**
    * Block to be rendered.
    *
@@ -57,6 +60,7 @@ class BlockSource extends SourcePluginBase {
     protected BlockManagerInterface $blockManager,
     protected PluginFormFactoryInterface $pluginFormFactory,
     protected ContextHandlerInterface $contextHandler,
+    protected CacheBackendInterface $cacheBackend,
   ) {
     parent::__construct($configuration, $plugin_id, $plugin_definition, $propTypeManager, $contextRepository, $routeMatch, $sampleEntityGenerator);
   }
@@ -80,7 +84,8 @@ class BlockSource extends SourcePluginBase {
       $container->get('ui_patterns.sample_entity_generator'),
       $container->get('plugin.manager.block'),
       $container->get('plugin_form.factory'),
-      $container->get('context.handler')
+      $container->get('context.handler'),
+      $container->get('cache.default'),
     );
     return $instance;
   }
@@ -274,6 +279,34 @@ class BlockSource extends SourcePluginBase {
     $context_for_block_discovery = $this->context;
     $definitions = $this->blockManager->getFilteredDefinitions('ui_patterns', $context_for_block_discovery, []);
     $definitions = $this->contextHandler->filterPluginDefinitionsByContexts($context_for_block_discovery, $definitions);
+    // ---
+    $metadataAboutBlocks = [];
+    $cached_version = $this->cacheBackend->get(static::CACHE_KEY);
+    if ($cached_version) {
+      $metadataAboutBlocks = $cached_version->data;
+    }
+    // @todo Add a way to alter this list properly (hook, event, etc).
+    $whitelisted_blocks = [
+      "id" => ["search_form_block", "system_menu_block"],
+      "provider" => ["layout_builder", "ui_patterns", "ui_patterns_blocks", "views"],
+    ];
+    foreach ($definitions as $plugin_id => $definition) {
+      if (!isset($metadataAboutBlocks[$plugin_id])) {
+        $blockAccepted = TRUE;
+        if (in_array($definition['provider'], $whitelisted_blocks["provider"]) ||
+          in_array($definition["id"], $whitelisted_blocks["id"])) {
+          $blockAccepted = TRUE;
+        }
+        elseif (isset($definition['class']) && static::classImplementsMethod($definition['class'], 'blockSubmit')) {
+          $blockAccepted = FALSE;
+        }
+        $metadataAboutBlocks[$plugin_id] = $blockAccepted;
+      }
+    }
+    $definitions = array_filter($definitions, function ($plugin_id) use ($metadataAboutBlocks) {
+      return $metadataAboutBlocks[$plugin_id];
+    }, ARRAY_FILTER_USE_KEY);
+    $this->cacheBackend->set(static::CACHE_KEY, $metadataAboutBlocks, CacheBackendInterface::CACHE_PERMANENT);
     // Order by category, and then by admin label.
     $definitions = $this->blockManager->getSortedDefinitions($definitions);
     /*
@@ -284,6 +317,28 @@ class BlockSource extends SourcePluginBase {
     return $definitions;
   }
 
+  /**
+   * Checks if a class implements a method.
+   *
+   * @param string $class_name
+   *   The fully qualified class name.
+   * @param string $method_name
+   *   Method name to check.
+   *
+   * @return bool
+   *   TRUE if the class implements the method, FALSE otherwise.
+   */
+  protected static function classImplementsMethod(string $class_name, string $method_name) : bool {
+    try {
+      $reflector = new \ReflectionClass($class_name);
+      return ($reflector->hasMethod($method_name) && $reflector->getMethod($method_name)->getDeclaringClass()->getName() === $class_name);
+    }
+    catch (\ReflectionException $e) {
+      // Handle exception if class does not exist or method not found.
+    }
+    return TRUE;
+  }
+
   /**
    * Get options for block select.
    */