WIP

config/install/patternkit.settings.yml

@@ -6,3 +6,4 @@ patternkit_json_editor_js: ""
 patternkit_json_editor_theme: bootstrap4
 patternkit_libraries: []
 patternkit_render_cache: true
+patternkit_pl_host: https://demo.patternlab.io/api

patternkit.links.task.yml

@@ -22,3 +22,7 @@ patternkit.settings.json_settings:
   title: 'JSON Pattern Library Settings'
   route_name: patternkit.settings.json_settings
   base_route: patternkit.settings
+patternkit.settings.rest_settings:
+  title: 'REST Pattern Library Settings'
+  route_name: patternkit.settings.rest_settings
+  base_route: patternkit.settings

patternkit.routing.yml

@@ -55,3 +55,13 @@ patternkit.settings.json_settings:
     _admin_route: TRUE
   requirements:
     _permission: 'access administration pages'
+patternkit.settings.rest_settings:
+  path: '/admin/config/user-interface/patternkit/rest'
+  defaults:
+    _form: '\Drupal\patternkit\Form\PatternLibraryRESTForm'
+    _title: 'Patternkit REST Library settings'
+    _description: 'Configure Patternkit REST Pattern Library Support.'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _permission: 'access administration pages'

patternkit.services.yml

@@ -20,6 +20,9 @@ services:
   patternkit.library.discovery.parser.json:
     class: Drupal\patternkit\PatternLibraryParser\JSONPatternLibraryParser
     arguments: ['@serialization.json', '@app.root', '@module_handler', '@theme.manager']
+  patternkit.library.discovery.parser.rest:
+    class: Drupal\patternkit\PatternLibraryParser\RESTPatternLibraryParser
+    arguments: ['@cache.default', '@http_client', '@config.factory', '@file_system', '@logger.channel.patternkit', '@serialization.json', '@stream_wrapper_manager']
   patternkit.library.discovery.parser.twig:
     class: Drupal\patternkit\PatternLibraryParser\TwigPatternLibraryParser
     arguments: ['@serialization.json', '@app.root', '@module_handler', '@theme.manager']

src/Form/PatternLibraryJSONForm.php

@@ -133,4 +133,17 @@ public function getFormId() :string {
     return 'patternkit_json_editor_config';
   }
 
+  /**
+   * {@inheritDoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state): void {
+    $this->config(static::SETTINGS)
+      ->set('patternkit_json_editor_theme', $form_state->getValue('patternkit_json_editor_theme'))
+      ->set('patternkit_json_editor_icons', $form_state->getValue('patternkit_json_editor_icons'))
+      ->set('patternkit_json_editor_css', $form_state->getValue('patternkit_json_editor_css'))
+      ->set('patternkit_json_editor_js', $form_state->getValue('patternkit_json_editor_js'))
+      ->save();
+    parent::submitForm($form, $form_state);
+  }
+
 }

src/Form/PatternLibraryRESTForm.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace Drupal\patternkit\Form;
+
+use Drupal\Core\Form\ConfigFormBase;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Settings form for configuring the REST Library Plugin.
+ */
+class PatternLibraryRESTForm extends ConfigFormBase {
+
+  /**
+   * Settings identifier.
+   *
+   * @var string
+   */
+  public const SETTINGS = 'patternkit.settings';
+
+  /**
+   * Implements buildForm().
+   *
+   * {@inheritDoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state) :array {
+    $config = $this->config(static::SETTINGS);
+
+    $form['patternkit_pl_host'] = array(
+      '#type' => 'textfield',
+      '#title' => t('PatternLab Host Web Address'),
+      '#description' => t('Enter the website address of the PatternLab host REST endpoint.'),
+      '#default_value' => $config->get('patternkit_pl_host'),
+    );
+
+    return parent::buildForm($form, $form_state);
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  protected function getEditableConfigNames() :array {
+    return [static::SETTINGS];
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  public function getFormId() :string {
+    return 'patternkit_rest_editor_config';
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state): void {
+    $this->config(static::SETTINGS)
+      ->set('patternkit_pl_host', $form_state->getValue('patternkit_pl_host'))
+      ->save();
+    parent::submitForm($form, $form_state);
+  }
+
+}

src/Form/PatternkitSettingsForm.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\patternkit\Form;
 
+use Drupal\Core\Config\Config;
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
@@ -130,8 +131,7 @@ public function getFormId() :string {
    * {@inheritDoc}
    */
   public function submitForm(array &$form, FormStateInterface $form_state): void {
-    $config = $this->config(static::SETTINGS);
-    $config
+    $config = $this->config(static::SETTINGS)
       ->set('patternkit_libraries', $form_state->getValue('patternkit_libraries'))
       ->set('patternkit_cache_enabled', $form_state->getValue('patternkit_cache_enabled'))
       ->set('patternkit_render_cache', $form_state->getValue('patternkit_render_cache'))

src/Loader/PatternLibraryLoader.php

@@ -2,13 +2,16 @@
 
 namespace Drupal\patternkit\Loader;
 
+use Drupal\Component\Plugin\Exception\PluginException;
 use Drupal\Core\Logger\LoggerChannelInterface;
 use Drupal\patternkit\PatternLibraryCollector;
+use Twig\Error\LoaderError;
+use Twig_LoaderInterface;
 
 /**
  * Functionality for parsing Twig pattern libraries.
  */
-class PatternLibraryLoader extends \Twig_Loader_Filesystem {
+class PatternLibraryLoader extends \Twig_Loader_Filesystem implements Twig_LoaderInterface {
 
   /**
    * Overrides to add paths from pattern libraries.
@@ -21,6 +24,7 @@ class PatternLibraryLoader extends \Twig_Loader_Filesystem {
    *   Provides library names and paths.
    *
    * @throws \Twig\Error\LoaderError
+   *   Thrown when encountering a cascaded loader error.
    */
   public function __construct($paths,
     LoggerChannelInterface $logger,
@@ -30,8 +34,10 @@ public function __construct($paths,
     try {
       $libraries = $pattern_collector->getLibraryDefinitions();
     }
-    catch (\Exception $exception) {
-      $logger->error('Error loading pattern libraries: @message', ['@message' => $exception->getMessage()]);
+    catch (PluginException $exception) {
+      $message = $exception->getMessage();
+      $logger->error('Error loading pattern libraries: @message', ['@message' => $message]);
+      throw new LoaderError($message);
     }
     foreach ($libraries as $namespace => $library) {
       $path = $library['data'];

src/PatternLibraryCollector.php

@@ -20,6 +20,7 @@
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\Core\Cache\CacheCollector;
 use Drupal\Core\Lock\LockBackendInterface;
+use function is_array;
 
 /**
  * The PatternLibraryCollector caches library information and performs retrieval
@@ -129,7 +130,7 @@ public static function create(ContainerInterface $container): self {
     /** @var \Drupal\Core\Lock\LockBackendInterface $lock */
     $lock = $container->get('lock');
     /** @var \Drupal\Core\Logger\LoggerChannelInterface $logger */
-    $logger = $container->get('@logger.channel.default');
+    $logger = $container->get('logger.channel.patternkit');
     /** @var \Drupal\Core\Extension\ModuleHandlerInterface $module_handler */
     $module_handler = $container->get('module_handler');
     /** @var string $root */
@@ -210,7 +211,7 @@ public function buildByExtension($extension_type, $extension): array {
     $libraries = $this->applyLibrariesOverride($libraries, $extension);
 
     foreach ($libraries as $id => &$library) {
-      if (!isset($library['patterns'])) {
+      if (!isset($library['patterns']) || !is_array($library['patterns'])) {
         unset($libraries[$id]);
         continue;
       }

src/PatternLibraryParser/FilePatternLibraryParser.php

@@ -10,6 +10,7 @@
 use Drupal\patternkit\PatternEditorConfig;
 use Drupal\patternkit\PatternLibraryJSONParserTrait;
 use Drupal\patternkit\PatternLibraryParserBase;
+use Symfony\Component\Finder\Iterator\RecursiveDirectoryIterator;
 
 /**
  * Parses a File pattern library collection into usable metadata.
@@ -39,6 +40,50 @@ public function __construct(
     parent::__construct($root, $module_handler, $theme_manager);
   }
 
+  /**
+   * Returns an array of file components grouped by file basename and extension.
+   *
+   * @param string $path
+   *   The fully-qualified path to discover component files.
+   * @param array $filter
+   *   An optional filter of file extensions to search for.
+   *
+   * @return array
+   *   Array of file components.
+   *   [basename][extension] = filename.
+   */
+  public static function discoverComponents($path, array $filter = []): array {
+    $components = [];
+    $rdit = new RecursiveDirectoryIterator($path, \FilesystemIterator::KEY_AS_PATHNAME | \FilesystemIterator::CURRENT_AS_FILEINFO);
+    /** @var \SplFileInfo $file */
+    foreach (new \RecursiveIteratorIterator($rdit) as $file) {
+      // Skip directories and non-files.
+      if (!$file->isFile()) {
+        continue;
+      }
+      $file_path = $file->getPath();
+
+      // Skip tests folders.
+      if (strpos($file_path, '/tests') !== FALSE) {
+        continue;
+      }
+
+      // Get the file extension for the file.
+      $file_ext = $file->getExtension();
+      if (!in_array(strtolower($file_ext), $filter, TRUE)) {
+        continue;
+      }
+
+      // We use file_basename as a unique key, it is required that the
+      // JSON and twig file share this basename.
+      $file_basename = $file->getBasename('.' . $file_ext);
+
+      // Build an array of all the filenames of interest, keyed by name.
+      $components[$file_basename][$file_ext] = "$file_path/$file_basename.$file_ext";
+    }
+    return $components;
+  }
+
   /**
    * Fetches all assets for a pattern.
    *