ex_icons-8.x-1.0/src/Discovery/SvgSymbolDiscovery.php

<?php

namespace Drupal\ex_icons\Discovery;

use Drupal\Component\Discovery\DiscoverableInterface;
use Drupal\Component\FileCache\FileCacheFactory;
use Drupal\Core\File\FileUrlGeneratorInterface;
use Drupal\ex_icons\Serialization\SvgSpriteSheet;

/**
 * Provides discovery for SVG symbol icons within a given set of directories.
 */
class SvgSymbolDiscovery implements DiscoverableInterface {
  /**
   * The basename of the file to look for in each directory.
   *
   * @var string
   */
  protected $basename;

  /**
   * An array of directories to scan, keyed by the provider.
   *
   * @var array
   */
  protected $directories = [];

  /**
   * The file URL generator.
   *
   * @var \Drupal\Core\File\FileUrlGeneratorInterface
   */
  protected $fileUrlGenerator;

  /**
   * Constructs a SvgSymbolDiscovery object.
   *
   * @param string $basename
   *   The basename of the file to look for in each directory. Can include
   *   slashes to designate sub-directories.
   * @param array $directories
   *   An array of directories to scan, keyed by the provider.
   */
  public function __construct($basename, array $directories) {
    $this->basename = $basename;
    $this->directories = $directories;
  }

  /**
   * {@inheritdoc}
   */
  public function findAll() {
    $all = [];

    $files = $this->findFiles();
    $provider_by_files = array_flip($files);

    $file_cache = FileCacheFactory::get('svg_symbol_discovery');

    // Try to load from the file cache first.
    foreach ($file_cache->getMultiple($files) as $file => $data) {
      $all[$provider_by_files[$file]] = $data;
      unset($provider_by_files[$file]);
    }

    // If there are files left that were not returned from the cache, load and
    // parse them now. This list was flipped above and is keyed by filename.
    if ($provider_by_files) {
      foreach ($provider_by_files as $file => $provider) {
        $data     = $this->decode($file);
        $file_url = $this->transformFileUrl($file);
        // Generate a hash based on the sprite sheet content for browser
        // cache versioning purposes.
        $hash = substr(hash_file('sha256', $file), 0, 16);

        $all[$provider] = ['base_url' => "$file_url?$hash"] + $data;

        $file_cache->set($file, $all[$provider]);
      }
    }

    return $all;
  }

  /**
   * Decode a SVG sprite sheet file.
   *
   * @param string $file
   *   SVG file path.
   *
   * @return array
   *   SVG sprite sheet data.
   */
  protected function decode($file) {
    // If a file is empty or its contents are commented out, return an empty
    // array instead of NULL for type consistency.
    return SvgSpriteSheet::decode(file_get_contents($file)) ?: [];
  }

  /**
   * Returns an array of file paths, keyed by provider.
   *
   * @return string[]
   *   The list of file paths, keyed by provider.
   */
  protected function findFiles() {
    $files = [];

    foreach ($this->directories as $provider => $directory) {
      $file = "$directory/$this->basename.svg";
      if (file_exists($file)) {
        $files[$provider] = $file;
      }
    }

    return $files;
  }

  /**
   * Gets the file url generator.
   *
   * @return \Drupal\Core\File\FileUrlGeneratorInterface
   *   The file url generator.
   */
  protected function getFileUrlGenerator() {
    // @phpstan-ignore-next-line
    if (!$this->fileUrlGenerator && \Drupal::hasService('file_url_generator')) {
      // @phpstan-ignore-next-line
      $this->fileUrlGenerator = \Drupal::service('file_url_generator');
    }

    return $this->fileUrlGenerator;
  }

  /**
   * Sets the file URL generator to use.
   *
   * @param \Drupal\Core\File\FileUrlGeneratorInterface $file_url_generator
   *   The file URL generator.
   *
   * @return $this
   *   Returns self for chaining.
   */
  public function setFileUrlGenerator(FileUrlGeneratorInterface $file_url_generator) {
    $this->fileUrlGenerator = $file_url_generator;
    return $this;
  }

  /**
   * Transforms a file path to a relative, web-accessible URL.
   *
   * @todo Remove this Drupal-specific code so this class is independent of
   *   Drupal, to follow the convention of
   *   \Drupal\Component\Discovery\YamlDiscovery and
   *   \Drupal\Component\Discovery\YamlDirectoryDiscovery.
   *
   * @param string $file_path
   *   The path to transform.
   *
   * @return string
   *   The transformed, web-accessible URL.
   */
  protected function transformFileUrl($file_path) {
    // @phpstan-ignore-next-line
    $relative = str_replace(\Drupal::root() . '/', '', $file_path);

    return $this->getFileUrlGenerator()->generateString($relative);
  }

}