newFilter method

Future<int?> newFilter({ required EthereumDefaultBlock fromBlock, required EthereumDefaultBlock toBlock, dynamic address, List<EthereumData>? topics, })

New filter Creates a filter object, based on filter options, to notify when the state changes (logs). To check if the state has changed, call getFilterChanges. note on specifying topic filters: Topics are order-dependent. A transaction with a log with topics A, B will be matched by the following topic filters: [] 'anything' 'A' 'A in first position (and anything after)' null, B 'anything in first position AND B in second position (and anything after)' A, B 'A in first position AND B in second position (and anything after)' [A, B, A, B] '(A OR B) in first position AND (A OR B) in second position (and anything after)' fromBlock: - (optional, default: 'latest') Integer block number, or 'latest' for the last mined block or 'pending', 'earliest' for not yet mined transactions. toBlock: - (optional, default: 'latest') Integer block number, or 'latest' for the last mined block or 'pending', 'earliest' for not yet mined transactions. address: - (optional) Contract address or a list of addresses from which logs should originate. topics: - (optional) topics. Topics are order-dependent. Note: the user must build this structure using the utilities in the EthereumUtilities class. See the Ethereum Wiki RPC page for examples. Returns a filter id.

Implementation

Future<int?> newFilter(
    {required EthereumDefaultBlock fromBlock,
    required EthereumDefaultBlock toBlock,
    dynamic address,
    List<EthereumData>? topics}) async {
  final fromBlockString = fromBlock.getSelection();
  final toBlockString = toBlock.getSelection();
  final params = <String, dynamic>{
    'toBlock': toBlockString,
    'fromBlock': fromBlockString
  };
  if (address != null) {
    if (address is List) {
      final addresses =
          EthereumAddress.toStringList(address as List<EthereumAddress>);
      params['address'] = addresses;
    } else {
      params['address'] = <String?>[address.asString];
    }
  }
  if (topics != null) {
    params['topics'] = EthereumData.toStringList(topics);
  }
  final paramBlock = <dynamic>[params];
  const method = EthereumRpcMethods.newFilter;
  final dynamic res = await _client.rpcClient.request(method, paramBlock);
  if (res != null && res.containsKey(EthereumConstants.ethResultKey)) {
    return EthereumUtilities.hexToInt(res[EthereumConstants.ethResultKey]);
  }
  _client.processError(method, res);
  return null;
}