Subscribe to user status

Subscribe to target users' online presence and multi-device connection statuses using subscribeUsersStatus:onSuccess:onFailure:. Once subscribed, the client receives real-time updates when those users log in, disconnect, or change active platforms.

Parameters

Code example

[[OIMManager manager] subscribeUsersStatus:userIDs
                                 onSuccess:^(NSArray<OIMUserStatusInfo *> *states) {
    [presenceStore mergeStates:states];
}
                                 onFailure:^(NSInteger code, NSString *message) {
    NSLog(@"subscribeUsersStatus failed: %ld %@", (long)code, message);
}];

When users scroll out of view or when leaving the screen, invoke Unsubscribe from user status to release subscription quotas.

Return value

The onSuccess callback delivers an array of OIMUserStatusInfo objects capturing the initial presence state and active client platforms for all successfully subscribed users.

State changes after the call

• Local state merge: Merge presence records into local UI collections using userID as the unique entity key.
• Asynchronous event listening: Receive ongoing presence updates via the onUserStatusChanged: delegate in OIMUserListener.
• Re-query calibration: To refresh snapshots of active subscriptions, invoke Refresh subscribed user status.

@interface PresenceStore () <OIMUserListener>
@end

@implementation PresenceStore

- (void)startListening {
    [[OIMManager callbacker] addUserListener:self];
}

- (void)stopListening {
    [[OIMManager callbacker] removeUserListener:self];
}

- (void)onUserStatusChanged:(OIMUserStatusInfo *)status {
    [self updateUserStatus:status];
}

@end

Retain this listener instance strongly, and invoke removeUserListener: when logging out or switching user accounts.