Custom message types

Beyond built-in message types, you can create custom message types by subclassing:

• NCMessageContent — for regular messages (text, location, etc.) that do not involve media file uploads.
• NCMediaMessageContent — for media messages that require upload/download handling (images, files, etc.).

Create a custom message type

Custom message types must conform to these protocols:

Encoding protocol (required)

The NCMessageCoding protocol defines message type identification, serialization/deserialization, and search keywords:

Swift

swift

import NexconnChatSDK
+ getObjectName;          // Unique type identifier (avoid "RC:" prefix)
- encode;                   // Serialize to JSON for transmission
- (void)decodeWithData:data; // Deserialize from JSON
- (NSArray<NSString *> *)getSearchableWords; // Return nil if not searchable

Objective-C

Objective C

+ (NSString *)getObjectName;          // Unique type identifier (avoid "RC:" prefix)
- (NSData *)encode;                   // Serialize to JSON for transmission
- (void)decodeWithData:(NSData *)data; // Deserialize from JSON
- (NSArray<NSString *> *)getSearchableWords; // Return nil if not searchable

Storage protocol (required)

The NCMessagePersistentCompatible protocol controls storage and unread count behavior:

Swift

swift

import NexconnChatSDK
+ (MessagePersistent)persistentFlag

Objective-C

Objective C

+ (NCMessagePersistent)persistentFlag;

Flag	Local storage	Server storage	Counts as unread
NCMessagePersistentNone	No	Supports missed messages	No
NCMessagePersistentCounted	Yes	Yes (stored in history)	Yes
NCMessagePersistentPersisted	Yes	Yes (stored in history)	No
NCMessagePersistentStatus	No	No	No

Content summary protocol (optional)

The NCMessageContentView protocol defines how the message appears in channel lists and local notifications:

Swift

swift

import NexconnChatSDK
- conversationDigest

Objective-C

Objective C

- (NSString *)conversationDigest;

Register a custom message type

Register your custom type after SDK initialization and before connecting:

Swift

swift

import NexconnChatSDK
NCEngine registerCustomMessages:@[MyCustomMessage.class

Objective-C

Objective C

[NCEngine registerCustomMessages:@[MyCustomMessage.class]];

tip

Unregistered types appear as RC:UnknownMsg.

Send custom messages

• Subclasses of NCMessageContent: use sendMessage.
• Subclasses of NCMediaMessageContent: use sendMediaMessage.

Push notifications for custom messages

Specify pushContent when sending custom messages to support push notifications. Without pushContent, the server cannot trigger push for custom types.

tip

Transient messages (NCMessagePersistentStatus) do not support push.