Credentials.fromJson constructor

Credentials.fromJson(String json)

Loads a set of credentials from a JSON-serialized form.

Throws a FormatException if the JSON is incorrectly formatted.

Implementation

factory Credentials.fromJson(String json) {
  void validate(condition, message) {
    if (condition) return;
    throw FormatException('Failed to load credentials: $message.\n\n$json');
  }

  var parsed;
  try {
    parsed = jsonDecode(json);
  } on FormatException {
    validate(false, 'invalid JSON');
  }

  validate(parsed is Map, 'was not a JSON map');
  validate(parsed.containsKey('accessToken'),
      'did not contain required field "accessToken"');
  validate(
      parsed['accessToken'] is String,
      'required field "accessToken" was not a string, was '
      '${parsed["accessToken"]}');

  for (var stringField in ['refreshToken', 'idToken', 'tokenEndpoint']) {
    var value = parsed[stringField];
    validate(value == null || value is String,
        'field "$stringField" was not a string, was "$value"');
  }

  var scopes = parsed['scopes'];
  validate(scopes == null || scopes is List,
      'field "scopes" was not a list, was "$scopes"');

  var tokenEndpoint = parsed['tokenEndpoint'];
  if (tokenEndpoint != null) {
    tokenEndpoint = Uri.parse(tokenEndpoint);
  }
  var expiration = parsed['expiration'];
  if (expiration != null) {
    validate(expiration is int,
        'field "expiration" was not an int, was "$expiration"');
    expiration = DateTime.fromMillisecondsSinceEpoch(expiration);
  }

  return Credentials(parsed['accessToken'],
      refreshToken: parsed['refreshToken'],
      idToken: parsed['idToken'],
      tokenEndpoint: tokenEndpoint,
      scopes: (scopes as List).map((scope) => scope as String),
      expiration: expiration);
}