Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Asset;
Chris@0: 
Chris@0: /**
Chris@0:  * Resolves the dependencies of asset (CSS/JavaScript) libraries.
Chris@0:  */
Chris@0: class LibraryDependencyResolver implements LibraryDependencyResolverInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The library discovery service.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Asset\LibraryDiscoveryInterface
Chris@0:    */
Chris@0:   protected $libraryDiscovery;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a new LibraryDependencyResolver instance.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Asset\LibraryDiscoveryInterface $library_discovery
Chris@0:    *   The library discovery service.
Chris@0:    */
Chris@0:   public function __construct(LibraryDiscoveryInterface $library_discovery) {
Chris@0:     $this->libraryDiscovery = $library_discovery;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getLibrariesWithDependencies(array $libraries) {
Chris@0:     return $this->doGetDependencies($libraries);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Gets the given libraries with its dependencies.
Chris@0:    *
Chris@0:    * Helper method for ::getLibrariesWithDependencies().
Chris@0:    *
Chris@0:    * @param string[] $libraries_with_unresolved_dependencies
Chris@0:    *   A list of libraries, with unresolved dependencies, in the order they
Chris@0:    *   should be loaded.
Chris@0:    * @param string[] $final_libraries
Chris@0:    *   The final list of libraries (the return value) that is being built
Chris@0:    *   recursively.
Chris@0:    *
Chris@0:    * @return string[]
Chris@0:    *   A list of libraries, in the order they should be loaded, including their
Chris@0:    *   dependencies.
Chris@0:    */
Chris@0:   protected function doGetDependencies(array $libraries_with_unresolved_dependencies, array $final_libraries = []) {
Chris@0:     foreach ($libraries_with_unresolved_dependencies as $library) {
Chris@0:       if (!in_array($library, $final_libraries)) {
Chris@0:         list($extension, $name) = explode('/', $library, 2);
Chris@0:         $definition = $this->libraryDiscovery->getLibraryByName($extension, $name);
Chris@0:         if (!empty($definition['dependencies'])) {
Chris@0:           $final_libraries = $this->doGetDependencies($definition['dependencies'], $final_libraries);
Chris@0:         }
Chris@0:         $final_libraries[] = $library;
Chris@0:       }
Chris@0:     }
Chris@0:     return $final_libraries;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getMinimalRepresentativeSubset(array $libraries) {
Chris@17:     assert(count($libraries) === count(array_unique($libraries)), '$libraries can\'t contain duplicate items.');
Chris@17: 
Chris@0:     $minimal = [];
Chris@0: 
Chris@0:     // Determine each library's dependencies.
Chris@0:     $with_deps = [];
Chris@0:     foreach ($libraries as $library) {
Chris@0:       $with_deps[$library] = $this->getLibrariesWithDependencies([$library]);
Chris@0:     }
Chris@0: 
Chris@0:     foreach ($libraries as $library) {
Chris@0:       $exists = FALSE;
Chris@0:       foreach ($with_deps as $other_library => $dependencies) {
Chris@0:         if ($library == $other_library) {
Chris@0:           continue;
Chris@0:         }
Chris@0:         if (in_array($library, $dependencies)) {
Chris@0:           $exists = TRUE;
Chris@0:           break;
Chris@0:         }
Chris@0:       }
Chris@0:       if (!$exists) {
Chris@0:         $minimal[] = $library;
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $minimal;
Chris@0:   }
Chris@0: 
Chris@0: }