Retrieving channels

The Nexconn SDK generates channels in the local database based on messages sent and received, and maintains a channel list. Your app can query the local database to retrieve this channel list.

Get a specific channel

Construct a channel instance and call reload() to refresh its latest data from the local database.

Kotlin

kotlin

// Get a direct channel
val directChannel = DirectChannel("userId")

directChannel.reload { updatedChannel, error ->
    if (error == null && updatedChannel != null) {
        println("Channel ID: ${updatedChannel.channelId}")
        println("Unread count: ${updatedChannel.unreadCount}")
        println("Pinned: ${updatedChannel.isPinned}")
    } else {
        // Failed: ${error?.message}
    }
}

// Get a group channel
val groupChannel = GroupChannel("groupId")

groupChannel.reload { updatedChannel, error ->
    if (error == null && updatedChannel != null) {
        println("Channel ID: ${updatedChannel.channelId}")
    }
}

Java

Java

// Get a direct channel
DirectChannel directChannel = new DirectChannel("userId");

directChannel.reload((updatedChannel, error) -> {
    if (error == null && updatedChannel != null) {
        System.out.println("Channel ID: " + updatedChannel.getChannelId());
        System.out.println("Unread count: " + updatedChannel.getUnreadCount());
        System.out.println("Pinned: " + updatedChannel.getIsPinned());
    } else {
        // Failed
    }
});

// Get a group channel
GroupChannel groupChannel = new GroupChannel("groupId");

groupChannel.reload((updatedChannel, error) -> {
    if (error == null && updatedChannel != null) {
        System.out.println("Channel ID: " + updatedChannel.getChannelId());
    }
});

Get multiple channels

Call BaseChannel.getChannels() to retrieve detailed information for multiple channels at once.

Kotlin

kotlin

val identifiers = listOf(
    ChannelIdentifier(ChannelType.DIRECT, "userId1"),
    ChannelIdentifier(ChannelType.DIRECT, "userId2"),
    ChannelIdentifier(ChannelType.GROUP, "groupId1")
)

BaseChannel.getChannels(identifiers) { channels, error ->
    if (error == null && channels != null) {
        channels.forEach { channel ->
            println("Channel: ${channel.channelId}, Type: ${channel.channelType}")
        }
    } else {
        // Failed: ${error?.message}
    }
}

Java

Java

List<ChannelIdentifier> identifiers = new ArrayList<>();
identifiers.add(new ChannelIdentifier(ChannelType.DIRECT, "userId1"));
identifiers.add(new ChannelIdentifier(ChannelType.DIRECT, "userId2"));
identifiers.add(new ChannelIdentifier(ChannelType.GROUP, "groupId1"));

BaseChannel.getChannels(identifiers, new OperationHandler<List<BaseChannel>>() {
    @Override
    public void onResult(List<BaseChannel> channels, NCError error) {
        if (error == null && channels != null) {
            for (BaseChannel channel : channels) {
                System.out.println("Channel: " + channel.getChannelId() + 
                                   ", Type: " + channel.getChannelType());
            }
        } else {
            // Failed
        }
    }
});

Get a channel list with pagination

Call BaseChannel.createChannelsQuery() to create a paginated query for the channel list.

Kotlin

kotlin

val params = ChannelsQueryParams(
    channelTypes = listOf(ChannelType.DIRECT, ChannelType.GROUP)
).apply {
    pageSize = 20
}

val query = BaseChannel.createChannelsQuery(params)

query.loadNextPage { page, error ->
    if (error == null && page != null) {
        page.data?.forEach { channel ->
            println("Channel: ${channel.channelId}")
            println("Unread: ${channel.unreadCount}")
            println("Last message: ${channel.latestMessage?.content}")
        }
    } else {
        // Failed: ${error?.message}
    }
}

Java

Java

ChannelsQueryParams params = new ChannelsQueryParams(
    Arrays.asList(ChannelType.DIRECT, ChannelType.GROUP)
);
params.setPageSize(20);

ChannelsQuery query = BaseChannel.createChannelsQuery(params);

query.loadNextPage(new OperationHandler<PageData<BaseChannel>>() {
    @Override
    public void onResult(PageData<BaseChannel> page, NCError error) {
        if (error == null && page != null) {
            for (BaseChannel channel : page.getData()) {
                System.out.println("Channel: " + channel.getChannelId());
                System.out.println("Unread: " + channel.getUnreadCount());
            }
        } else {
            // Failed
        }
    }
});

Query parameters

ChannelsQueryParams supports the following parameters:

Parameter	Type	Description
channelTypes	List<ChannelType>	List of channel types to query.
pageSize	Int	Number of channels per page. Default is 20.
topPriority	Boolean	Whether pinned channels are returned first. Default is true.
startTime	Long	Start time for the query in milliseconds. Default is 0L.

Channel properties

Each channel object returned includes the following common properties:

Property	Type	Description
channelId	String	Channel ID
channelType	ChannelType	Channel type
unreadCount	Int	Unread message count
latestMessage	Message?	Last message
isPinned	Boolean	Whether the channel is pinned
channelNoDisturbLevel	ChannelNoDisturbLevel	Notification level