fetchHistoryMessages method

Implementation

@Deprecated('Use [fetchHistoryMessagesByOption] instead')

/// ~english
/// Gets historical messages of the conversation from the server with pagination.
///
/// Param [conversationId] The conversation ID.
///
/// Param [type] The conversation type. See [EMConversationType].
///
/// Param [pageSize] The number of messages per page.
///
/// Param [direction] The message search direction. See [EMSearchDirection].
///
/// Param [startMsgId] The ID of the message from which you start to get the historical messages. If `null` is passed, the SDK gets messages in the reverse chronological order.
///
/// **Return** The obtained messages and the cursor for the next query.
///
/// **Throws** A description of the exception. See [EMError].
/// ~end
///
/// ~chinese
/// 从服务器分页获取历史消息。
///
/// Param [conversationId] 会话 ID。
///
/// Param [type] 会话类型，详见[EMConversationType]。
///
/// Param [pageSize] 每页获取的消息数量。
///
/// Param [direction] 要搜索的消息方向. 见 [EMSearchDirection].
///
/// Param [startMsgId] 获取历史消息的开始消息 ID，如果为空，从最新的消息向前开始获取。
///
/// **Return** 返回消息列表和用于继续获取历史消息的 [EMCursorResult]
///
/// **Throws**  如果有异常会在这里抛出，包含错误码和错误描述，详见 [EMError]。
/// ~end
Future<EMCursorResult<EMMessage>> fetchHistoryMessages({
  required String conversationId,
  EMConversationType type = EMConversationType.Chat,
  int pageSize = 20,
  EMSearchDirection direction = EMSearchDirection.Up,
  String startMsgId = '',
}) async {
  Map req = Map();
  req['convId'] = conversationId;
  req['type'] = conversationTypeToInt(type);
  req['pageSize'] = pageSize;
  req['startMsgId'] = startMsgId;
  req['direction'] = direction.index;
  Map result = await ChatChannel.invokeMethod(
      ChatMethodKeys.fetchHistoryMessages, req);
  try {
    EMError.hasErrorFromResult(result);
    return EMCursorResult<EMMessage>.fromJson(
        result[ChatMethodKeys.fetchHistoryMessages],
        dataItemCallback: (value) {
      return EMMessage.fromJson(value);
    });
  } on EMError catch (e) {
    throw e;
  }
}