load method

Future<Uri> load(String fileName)

Loads a single fileName to the cache.

Returns a Uri to access that file.

Implementation

Future<Uri> load(String fileName) async {
  var needsFetch = !loadedFiles.containsKey(fileName);

  // Verify that the cached file still exists. It can be removed
  // by the system when the storage is almost full
  // Android: https://developer.android.com/training/data-storage/app-specific#internal-remove-cache
  // iOS: https://developer.apple.com/documentation/foundation/using-the-file-system-effectively#Store-short-lived-files
  // Web: Uses a data uri, the content is not present on the file system.
  if (!kIsWeb &&
      !needsFetch &&
      !fileSystem.file(loadedFiles[fileName]).existsSync()) {
    needsFetch = true;
  }

  if (needsFetch) {
    loadedFiles[fileName] = await fetchToMemory(fileName);
  }
  return loadedFiles[fileName]!;
}