Get message history

Retrieve message history from a community subchannel using BaseChannel.createMessagesQuery().

Get local or remote messages

Dart

final query = BaseChannel.createMessagesQuery(MessagesQueryParams(
  channelIdentifier: ChannelIdentifier(
    channelType: ChannelType.community,
    channelId: '<community-id>',
    subChannelId: '<subchannel-id>',
  ),
  isAscending: false,
  policy: MessageOperationPolicy.localRemote,
  startTime: 0,
  pageSize: 20,
));

await query.loadNextPage((result, error) {
  if (error == null) {
    print('Loaded ${result?.data.length} messages');
    print('Total matched: ${result?.totalCount}');
  }
});

MessagesQueryParams

Parameter	Type	Default	Description
channelIdentifier	ChannelIdentifier	Required	Community channel identifier. Set subChannelId to the target subchannel.
isAscending	bool	false	Sort order. false loads newer-to-older messages, true loads older-to-newer messages.
policy	MessageOperationPolicy	local	Query source: local, remote, or localRemote.
messageType	MessageType	unknown	Message type filter. unknown means all types.
startTime	int	0	Start timestamp in milliseconds. 0 starts from the latest message when isAscending is false.
pageSize	int	20	Messages per page.

PageResult<Message>

Property	Type	Description
data	List<Message>	Messages returned in the current page.
totalCount	int	Total number of messages matched by the query.

Check whether messages still exist on the remote server

Use CommunityChannel.checkRemoteMessages() to verify whether specific community messages still exist on the server.

Method

Dart

static Future<int> checkRemoteMessages(List<Message> messages, OperationHandler<CheckRemoteMessagesResult> handler)

Code example

Dart

await CommunityChannel.checkRemoteMessages(
  messages,
  (result, error) {
    if (error == null) {
      print('Matched: ${result?.matched.length}');
      print('Not matched: ${result?.notMatched.length}');
    }
  },
);

CheckRemoteMessagesResult

Property	Type	Description
matched	List<Message>	Messages that still exist on the remote server.
notMatched	List<Message>	Messages that were not found on the remote server.

note

checkRemoteMessages() is a community-channel API. Pass community messages only.