doc method

DocumentReference<T> doc([ String? documentPath ])

Gets a DocumentReference instance that refers to the document at the specified path.

If no path is specified, an automatically-generated unique ID will be used for the returned DocumentReference.

If using withConverter, the path must not contain any slash.

Implementation

DocumentReference<T> doc([String? documentPath]) {
  if (documentPath != null) {
    _validateResourcePath('documentPath', documentPath);
  } else {
    documentPath = autoId();
  }

  final path = _resourcePath._append(documentPath);
  if (!path.isDocument) {
    throw ArgumentError.value(
      documentPath,
      'documentPath',
      'Value for argument "documentPath" must point to a document, but was '
          '"$documentPath". Your path does not contain an even number of components.',
    );
  }

  if (!identical(_queryOptions.converter, _jsonConverter) &&
      path._parent() != _resourcePath) {
    throw ArgumentError.value(
      documentPath,
      'documentPath',
      'Value for argument "documentPath" must not contain a slash (/) if '
          'the parent collection has a custom converter.',
    );
  }

  return DocumentReference<T>._(
    firestore: firestore,
    path: path,
    converter: _queryOptions.converter,
  );
}