uploadFile method

Implementation

Future<void> uploadFile(List<File> files) async {
  var isMultiple = await evaluate<bool>('element => element.multiple');
  if (files.length > 1 && !isMultiple!) {
    throw Exception(
        'Multiple file uploads only work with <input type=file multiple>');
  }

  var objectId = remoteObject.objectId;
  var node = await executionContext.domApi.describeNode(objectId: objectId);

  // The zero-length array is a special case, it seems that DOM.setFileInputFiles does
  // not actually update the files in that case, so the solution is to eval the element
  // value to a new FileList directly.
  if (files.isEmpty) {
    await evaluate('''element => {
      element.files = new DataTransfer().files;

      // Dispatch events for this case because it should behave akin to a user action.
      element.dispatchEvent(new Event('input', { bubbles: true }));
      element.dispatchEvent(new Event('change', { bubbles: true }));
    }''');
  } else {
    await executionContext.domApi.setFileInputFiles(
        files.map((file) => file.absolute.path).toList(),
        objectId: objectId,
        backendNodeId: node.backendNodeId);
  }
}