Issue #3340712: Add Single Directory Components as a new experimental module

core/modules/sdc/src/Component/ComponentMetadata.php

+<?php
+
+namespace Drupal\sdc\Component;
+
+use Drupal\Core\Extension\ExtensionLifecycle;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+use Drupal\sdc\Exception\InvalidComponentException;
+
+/**
+ * Component metadata.
+ *
+ * @internal
+ */
+final class ComponentMetadata {
+
+  use StringTranslationTrait;
+
+  /**
+   * The absolute path to the component directory.
+   *
+   * @var string
+   */
+  public readonly string $path;
+
+  /**
+   * The component documentation.
+   *
+   * @var string
+   */
+  public readonly string $documentation;
+
+  /**
+   * The status of the component.
+   *
+   * @var string
+   */
+  public readonly string $status;
+
+  /**
+   * The machine name for the component.
+   *
+   * @var string
+   */
+  public readonly string $machineName;
+
+  /**
+   * The component's name.
+   *
+   * @var string
+   */
+  public readonly string $name;
+
+  /**
+   * The PNG path for the component thumbnail.
+   *
+   * @var string
+   */
+  private string $thumbnailPath;
+
+  /**
+   * The component group.
+   *
+   * @var string
+   */
+  public readonly string $group;
+
+  /**
+   * Schema for the component props.
+   *
+   * @var array[]|null
+   *   The schemas.
+   */
+  public readonly ?array $schema;
+
+  /**
+   * The component description.
+   *
+   * @var string
+   */
+  public readonly string $description;
+
+  /**
+   * TRUE if the schemas for props and slots are mandatory.
+   *
+   * @var bool
+   */
+  public readonly bool $mandatorySchemas;
+
+  /**
+   * Slot information.
+   *
+   * @var array
+   */
+  public readonly array $slots;
+
+  /**
+   * ComponentMetadata constructor.
+   *
+   * @param array $metadata_info
+   *   The metadata info.
+   * @param string $app_root
+   *   The application root.
+   * @param bool $enforce_schemas
+   *   Enforces the definition of schemas for props and slots.
+   *
+   * @throws \Drupal\sdc\Exception\InvalidComponentException
+   */
+  public function __construct(array $metadata_info, string $app_root, bool $enforce_schemas) {
+    $path = $metadata_info['path'];
+    // Make the absolute path, relative to the Drupal root.
+    $app_root = rtrim($app_root, DIRECTORY_SEPARATOR) . DIRECTORY_SEPARATOR;
+    if (str_starts_with($path, $app_root)) {
+      $path = substr($path, strlen($app_root));
+    }
+    $this->mandatorySchemas = $enforce_schemas;
+    $this->path = $path;
+
+    [, $machine_name] = explode(':', $metadata_info['id'] ?? []);
+    $this->machineName = $machine_name;
+    $this->name = $metadata_info['name'] ?? mb_convert_case($machine_name, MB_CASE_TITLE);
+    $this->description = $metadata_info['description'] ?? $this->t('- Description not available -');
+    $this->status = ExtensionLifecycle::isValid($metadata_info['status'] ?? '')
+      ? $metadata_info['status']
+      : ExtensionLifecycle::STABLE;
+    $this->documentation = $metadata_info['documentation'] ?? '';
+
+    $this->group = $metadata_info['group'] ?? $this->t('All Components');
+
+    // Save the schemas.
+    $this->parseSchemaInfo($metadata_info);
+    $this->slots = $metadata_info['slots'] ?? [];
+  }
+
+  /**
+   * Parse the schema information.
+   *
+   * @param array $metadata_info
+   *   The metadata information as decoded from the component definition file.
+   *
+   * @throws \Drupal\sdc\Exception\InvalidComponentException
+   */
+  private function parseSchemaInfo(array $metadata_info): void {
+    if (empty($metadata_info['props'])) {
+      if ($this->mandatorySchemas) {
+        throw new InvalidComponentException(sprintf('The component "%s" does not provide schema information. Schema definitions are mandatory for components declared in modules. For components declared in themes, schema definitions are only mandatory if the "enforce_prop_schemas" key is set to "true" in the theme info file.', $metadata_info['id']));
+      }
+      $schema = NULL;
+    }
+    else {
+      $schema = $metadata_info['props'];
+      if (($schema['type'] ?? 'object') !== 'object') {
+        throw new InvalidComponentException('The schema for the props in the component metadata is invalid. The schema should be of type "object".');
+      }
+      if ($schema['additionalProperties'] ?? FALSE) {
+        throw new InvalidComponentException('The schema for the %s in the component metadata is invalid. Arbitrary additional properties are not allowed.');
+      }
+      $schema['additionalProperties'] = FALSE;
+      // All props should also support "object" this allows deferring rendering
+      // in Twig to the render pipeline.
+      $schema_props = $metadata_info['props'];
+      foreach ($schema_props['properties'] ?? [] as $name => $prop_schema) {
+        $type = $prop_schema['type'] ?? '';
+        $schema['properties'][$name]['type'] = array_unique([
+          ...(array) $type,
+          'object',
+        ]);
+      }
+    }
+    $this->schema = $schema;
+  }
+
+  /**
+   * Gets the thumbnail path.
+   *
+   * @return string
+   *   The path.
+   */
+  public function getThumbnailPath(): string {
+    if (!isset($this->thumbnailPath)) {
+      $thumbnail_path = sprintf('%s/thumbnail.png', $this->path);
+      $this->thumbnailPath = file_exists($thumbnail_path) ? $thumbnail_path : '';
+    }
+    return $this->thumbnailPath;
+  }
+
+  /**
+   * Normalizes the value object.
+   *
+   * @return array
+   *   The normalized value object.
+   */
+  public function normalize(): array {
+    return [
+      'path' => $this->path,
+      'machineName' => $this->machineName,
+      'status' => $this->status,
+      'name' => $this->name,
+      'group' => $this->group,
+    ];
+  }
+
+}