Angular service that acquires information asynchronously, but has dependents waiting for that info. (Pattern)

wait_for_config.dart

class ConfigService {
  var _config;
  
  Completer _waitForConfig = new Completer();
  
  ConfigService() {
    doHttpCall().then((result) {
      _config = result;
      _waitForConfig.complete(_config);
    }
  }

  Future get config => _waitForConfig.future;
}