Channel overview

The Chat SDK uses channel objects to represent channels. All channel types (Direct, Group, Open, Community, System) inherit from NCBaseChannel.

Channel types

Nexconn supports multiple channel types for different use cases. The client SDK uses the NCChannelType enum:

Enum value	Channel type
NCChannelTypeDirect	Direct channel
NCChannelTypeGroup	Group channel
NCChannelTypeCommunity	Community channel
NCChannelTypeOpen	Open channel
NCChannelTypeSystem	System channel

Direct channel

A one-to-one channel between two users. The two users do not need to be friends — Nexconn does not manage user relationships. Messages are stored in the local database.

Group channel

A channel with two or more users. Channel member information is managed by your app. Nexconn delivers messages to all group members. Each group supports up to 3,000 members with no limit on the number of groups per app. Messages are stored in the local database.

Community channel

A multi-user chat with no member limit. Supports high-volume concurrent messaging and push notifications. Member information is managed by your app. Each user can join up to 100 community channels. Messages are stored in the local database. See Community channel overview.

Open channel

Supports unlimited participants with high-volume concurrent real-time messaging. Users stop receiving messages after leaving the open channel. No push notification support. The SDK does not save open channel messages — all data is cleared when the user leaves. See Open channel overview.

System channel

A channel where system accounts send messages to users. These channels can be created by broadcast messages or single notification messages (for example, friend request notifications).

Channel properties

The NCBaseChannel class provides the following key properties:

Property	Type	Description
channelType	NCChannelType	Channel type: direct, group, open, system, or community
channelId	NSString	Channel ID. For direct channels, this is the other user's ID. For group/open/community channels, this is the corresponding channel ID.
unreadCount	NSInteger	Number of unread messages
mentionedMeCount	NSInteger	Number of unread messages that mention the current user
mentionedCount	NSInteger	Total number of mention messages
isPinned	BOOL	Whether the channel is pinned
noDisturbLevel	NCChannelNoDisturbLevel	Do not disturb level. See Do not disturb overview.
operationTime	long long	Operation timestamp in milliseconds. Updated by pinning and other operations. Used as cursor for paginated queries.
latestMessage	NCMessage	Last message stored locally. See Message types.
draft	NSString	Draft text saved in the channel. See Draft.
translateStrategy	NCTranslateStrategy	Text translation strategy for this channel

latestMessage (NCMessage) key properties:

Property	Type	Description
clientId	long long	Locally unique message ID
messageId	NSString	Server-assigned globally unique message ID (only available for successfully sent messages)
senderUserId	NSString	Sender's user ID
direction	NCMessageDirection	Message direction: send or receive
sentStatus	NCSentStatus	Message sending status
sentTime	long long	Send time (Unix timestamp in milliseconds)
messageType	NSString	Message type name
content	NCMessageContent	Message content body
metadata	NSDictionary	Message metadata
receivedStatusInfo	NCMessageReceivedStatusInfo	Message received status

Basic channel operations

Create or get a channel instance

Swift

swift

import NexconnChatSDK
// Direct channel
let directChannel = DirectChannel(channelId: "userId")
// Group channel
let groupChannel = GroupChannel(channelId: "groupId")
// Open channel
let openChannel = OpenChannel(channelId: "chatroomId")

Objective-C

Objective C

// Direct channel
NCDirectChannel *directChannel = [[NCDirectChannel alloc] initWithChannelId:@"userId"];

// Group channel
NCGroupChannel *groupChannel = [[NCGroupChannel alloc] initWithChannelId:@"groupId"];

// Open channel
NCOpenChannel *openChannel = [[NCOpenChannel alloc] initWithChannelId:@"chatroomId"];

Each call to initWithChannelId: returns a new channel instance configured with the given ID.

Get a channel instance

Swift

swift

import NexconnChatSDK
let identifier = ChannelIdentifier(channelType: .direct, channelId: "userId")
BaseChannel.getChannels(identifiers: [identifier]) { channels, error in
    guard let channel = channels?.first else { return }
    print("Channel loaded: \(channel.channelId)")
}

Objective-C

Objective C

NCChannelIdentifier *identifier =
    [[NCChannelIdentifier alloc] initWithChannelType:NCChannelTypeDirect
                                           channelId:@"userId"];

[NCBaseChannel getChannels:@[identifier]
                completion:^(NSArray<NCBaseChannel *> * _Nullable channels, NCError * _Nullable error) {
    NCBaseChannel *channel = channels.firstObject;
    if (channel != nil) {
        NSLog(@"Channel loaded: %@", channel.channelId);
    }
}];

If you already know the channel type and ID, you can also create a typed instance with initWithChannelId: and then call reloadWithCompletion: to fetch the latest state.

Release a channel instance

The current iOS SDK does not expose a destroy API on NCBaseChannel. Channel instances are lightweight objects. Release your own references when you no longer need an instance.

Create a channel list query

Swift

swift

import NexconnChatSDK
let params = ChannelsQueryParams()
params.setChannelTypes([.direct])
params.pageSize = 20
let query = BaseChannel.createChannelsQuery(params: params)
query.loadNextPage { page, error in
    let channels = page?.data ?? []
    print("Loaded \(channels.count) channels")
}

Objective-C

Objective C

NCChannelsQueryParams *params = [[NCChannelsQueryParams alloc] init];
params.channelTypes = @[@(NCChannelTypeDirect)];
params.pageSize = 20;

NCChannelsQuery *query = [NCBaseChannel createChannelsQueryWithParams:params];
[query loadNextPageWithCompletion:^(NSArray *channels, NCError *error) {
    if (!error) {
        NSLog(@"Loaded %lu channels", (unsigned long)channels.count);
    }
}];

Create a channel search query

Swift

swift

import NexconnChatSDK
let query = ChannelSearchQuery()
query.keyword = "Project"
query.loadNextPage { page, error in
    let channels = page?.data ?? []
    // Handle results
}

Objective-C

Objective C

NCChannelSearchQuery *query = [[NCChannelSearchQuery alloc] init];
query.keyword = @"Project";
[query loadNextPageWithCompletion:^(NSArray *channels, NCError *error) {
    // Handle results
}];

Mark multiple channels as read

Swift

swift

import NexconnChatSDK
for channel in channels {
    channel.clearUnreadCount(completion: nil)
}

Objective-C

Objective C

for (NCBaseChannel *channel in channels) {
    [channel clearUnreadCountWithCompletion:nil];
}

Delete multiple channels

Use deleteChannels:completion: (see Delete a channel).

Clear unread count

Use clearUnreadCountWithCompletion: on a channel instance (see Handle unread count).