function ExtensionMimeTypeGuesser::guessMimeType

File

core/lib/Drupal/Core/File/MimeType/ExtensionMimeTypeGuesser.php, line 900

Class

ExtensionMimeTypeGuesser

Makes possible to guess the MIME type of a file using its extension.

Namespace

Code

public function guessMimeType($path) : ?string {
  if ($this->mapping === NULL) {
    $mapping = $this->defaultMapping;
    // Allow modules to alter the default mapping.
    $this->moduleHandler
      ->alter('file_mimetype_mapping', $mapping);
    $this->mapping = $mapping;
  }
  $extension = '';
  $file_parts = explode('.', \Drupal::service('file_system')->basename($path));
  // Remove the first part: a full filename should not match an extension.
  array_shift($file_parts);
  // Iterate over the file parts, trying to find a match.
  // For my.awesome.image.jpeg, we try:
  // - jpeg
  // - image.jpeg, and
  // - awesome.image.jpeg
  while ($additional_part = array_pop($file_parts)) {
    $extension = strtolower($additional_part . ($extension ? '.' . $extension : ''));
    if (isset($this->mapping['extensions'][$extension])) {
      return $this->mapping['mimetypes'][$this->mapping['extensions'][$extension]];
    }
  }
  return 'application/octet-stream';
}