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Page event listeners

Chat UI provides two types of listeners:

  1. Global NCChatUI listeners: Connection status, network status, message policies, message events, and send interception.
  2. Page-level listeners: Various callbacks for the channel list page and channel page.

Global listeners​

Monitor connection status​

Objective C
[[NCChatUI shared] addConnectionStatusDelegate:self];
[[NCChatUI shared] removeConnectionStatusDelegate:self];

- (void)onNCChatUIConnectionStatusChanged:(NCConnectionStatus)status {
    // Handle connection status changes
}

Notification​

Chat UI also dispatches NCChatUIDispatchConnectionStatusChangedNotification, where the object is an NSNumber corresponding to NCConnectionStatus.

Monitor network status​

Objective C
@interface AppDelegate () <NCChatUINetworkStatusDelegate>
@end

- (void)setupNetworkDelegate {
    [[NCChatUI shared] addNetworkStatusDelegate:self];
}

- (void)onNCChatUINetworkStatusChanged:(NCChatUINetworkStatus)status {
    // status: No network / WiFi / Cellular
}

Message policies​

To control whether a message appears in the UI, plays an alert sound, or triggers a local notification, implement NCChatUIMessagePolicyDelegate:

Objective C
@interface AppDelegate () <NCChatUIMessagePolicyDelegate>
@end

- (void)setupMessagePolicy {
    [NCChatUI shared].messagePolicyDelegate = self;
}

- (BOOL)shouldInterceptMessage:(NCMessage *)message {
    return NO;
}

- (BOOL)shouldSuppressAlertSoundForMessage:(NCMessage *)message {
    return NO;
}

- (BOOL)shouldSuppressLocalNotificationForMessage:(NCMessage *)message
                                       senderName:(NSString *)senderName {
    return NO;
}

Message event listeners​

Use NCChatUIMessageEventObserver to listen for global message receive and delete events.

Objective C
@interface AppDelegate () <NCChatUIMessageEventObserver>
@end

- (void)setupMessageObserver {
    [[NCChatUI shared] addMessageEventObserver:self];
}

- (void)onReceivedMessage:(NCMessage *)message left:(int)left offline:(BOOL)offline {
    // Message received
}

- (void)onDeletedMessagesForAll:(NSArray<NCMessage *> *)messages {
    // Messages deleted globally
}

Send interception​

To modify content before sending, intercept sends, or integrate with custom file upload logic, implement NCChatUIMessageInterceptor:

Objective C
@interface AppDelegate () <NCChatUIMessageInterceptor>
@end

- (void)setupMessageInterceptor {
    [NCChatUI shared].messageInterceptor = self;
}

- (BOOL)interceptWillSendMessageWithParams:(NCChatUISendMessageParams *)params {
    return NO;
}

- (BOOL)interceptWillSendMediaMessageWithParams:(NCChatUISendMediaMessageParams *)params {
    return NO;
}

- (void)interceptDidSendMessage:(NCMessage *)message {
}

Channel list page events​

NCChannelListViewController provides these common entry points:

Before displaying channel cell​

Objective C
- (void)willDisplayConversationTableCell:(NCChannelListBaseCell *)cell
                             atIndexPath:(NSIndexPath *)indexPath;

Channel cell tap​

Objective C
- (void)onSelectedTableRow:(NCChannelModelType)conversationModelType
         conversationModel:(NCChannelModel *)model
               atIndexPath:(NSIndexPath *)indexPath;

Avatar tap and long press​

Objective C
- (void)didTapCellPortrait:(NCChannelModel *)model;
- (void)didLongPressCellPortrait:(NCChannelModel *)model;

Delete channel​

Objective C
- (void)didDeleteConversationCell:(NCChannelModel *)model;

Before loading data source​

Objective C
- (NSMutableArray<NCChannelModel *> *)willReloadTableData:(NSMutableArray<NCChannelModel *> *)dataSource;

Unread count update​

Objective C
- (void)notifyUpdateUnreadMessageCount;

Channel page events​

NCChannelViewController exposes these common callbacks.

Input box content change​

Objective C
- (void)inputTextView:(UITextView *)inputTextView
shouldChangeTextInRange:(NSRange)range
      replacementText:(NSString *)text;

Input area height change​

Objective C
- (void)chatInputBar:(NCChatSessionInputBarControl *)chatInputBar
   shouldChangeFrame:(CGRect)frame;

Before and after sending​

Objective C
- (NCMessageContent *)willSendMessage:(NCMessageContent *)messageContent;
- (void)didSendMessageModel:(NSInteger)status model:(NCMessageModel *)messageModel;
- (void)didCancelMessage:(NCMessageContent *)messageContent;

Before inserting and displaying messages​

Objective C
- (NCMessage *)willAppendAndDisplayMessage:(NCMessage *)message;
- (void)willDisplayMessageCell:(NCMessageBaseCell *)cell atIndexPath:(NSIndexPath *)indexPath;

Plugin panel tap​

Objective C
- (void)pluginBoardView:(NCPluginBoardView *)pluginBoardView
     clickedItemWithTag:(NSInteger)tag;
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