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Message Interception

The IMKit SDK allows intercepting messages before sending, after sending, and upon receipt.

Message interception provides the following protocols:

tip

The conversation page (RCConversationViewController) in IMKit also provides message interception-related methods willSendMessage: and didSendMessage:content:. For details, see Page Event Listeners.

Intercept Messages Before and After Sending (SDK ≧ 5.3.5)​

Through the callback methods provided by the RCIMMessageInterceptor protocol, you can intercept messages before and after sending, with access to the RCMessage object.

Possible use cases for intercepting messages before and after sending include:

  • Intercept and modify RCMessage before sending, then let the SDK continue sending (note: for 5.3.5 ≦ SDK < 5.4.5, this only supports modifying the content field of RCMessage; for SDK ≧ 5.4.5, modifying RCMessage is fully supported). In this case, return NO to indicate the app needs to intercept but requires the SDK to send the modified RCMessage.
  • Intercept and modify RCMessage before sending, then let the app resend. This fully supports modifying RCMessage. Return YES to indicate the app will handle the subsequent process and resend the modified message.
  • Intercept RCMessage before sending, upload media files to the app's designated file server, then let the app resend. Return YES to indicate the app will handle the subsequent process. Note: The app must call the custom file server upload method. See Sending Messages.
  • Intercept after sending to modify certain attributes of the RCMessage object in the database, such as additional info via setMessageExtra. See methods in RCCoreClient or RCChannelClient. Note: You may need to check the message's sent status (RCMessage.sentStatus) before deciding the next steps.

Setting the Delegate​

The RCIMMessageInterceptor delegate only needs to be set once globally. Multiple settings will override previous delegates.

[RCIM sharedRCIM].messageInterceptor = self;

To implement this, your class must conform to the RCIMMessageInterceptor protocol.

#pragma mark -- RCIMMessageInterceptor

- (BOOL)interceptWillSendMessage:(RCMessage *)message {
    if ([message.content isKindOfClass:[RCCombineMessage class]]) {
        // Example 1: Intercept combined-forwarded messages, let the app handle sending
        [[RCIM sharedRCIM] sendMediaMessage:message pushContent:nil pushData:nil uploadPrepare:^(RCUploadMediaStatusListener *uploadListener) {

            RCCombineMessage *msgContent = (RCCombineMessage *)uploadListener.currentMessage.content;
            msgContent.remoteUrl = @"https://your_file_server.com.com/test.html";
            uploadListener.successBlock(msgContent);

        } progress:nil successBlock:nil errorBlock:nil cancel:nil];
        // Return YES to let the app handle sending
        return YES;
    }
    else if ([message.content isKindOfClass:[RCImageMessage class]]) {
        // Example 2.1: Filter out unintercepted image messages (customize conditions as needed)
        RCImageMessage *msgContent = (RCImageMessage *)message.content;
        if ([msgContent.remoteUrl containsString:@"your_file_server"]) {
            // Image already uploaded to the app's file server; no need to intercept
            return NO;
        }

        // Example 2.2: Intercept image messages, let the app handle sending
        [[RCIM sharedRCIM] sendMediaMessage:message pushContent:nil pushData:nil uploadPrepare:^(RCUploadMediaStatusListener *uploadListener) {

            RCImageMessage *msgContent = (RCImageMessage *)uploadListener.currentMessage.content;
            // Implement custom file upload logic
            // Assign the uploaded file URL to remoteUrl
            msgContent.remoteUrl = @"http://your_file_server.com/test.jpg";
            uploadListener.successBlock(msgContent);

        } progress:nil successBlock:nil errorBlock:nil cancel:nil];

        // Return YES to let the app handle sending
        return YES;
    }

    else if ([message.content isKindOfClass:[RCTextMessage class]]) {
        // Example 3: Intercept and let the SDK continue sending after updating text content
        RCTextMessage *msgContent = (RCTextMessage *)message.content;
        msgContent.content = @"Text content has been replaced";

        // Return NO to let the SDK handle sending
        return NO;
    }

    return NO;
}

Intercept Received Messages​

The RCIMReceiveMessageDelegate protocol in IMKit provides methods for intercepting received messages.

For delegate setup, see Message Listeners. After setting the delegate, implement the interceptMessage: method. Return YES to intercept the received message, preventing further callbacks.

tip

This only determines whether the message is displayed immediately upon receipt. Returning YES intercepts the message, but reloading the conversation page will still display it. To prevent this, delete the message. See Deleting Messages.

@protocol RCIMReceiveMessageDelegate <NSObject>

/*!
 Callback when Kit receives a message
 @param message The received message
 @return YES: Intercept (do not display); NO: Do not intercept (display the message).
 */

- (BOOL)interceptMessage:(RCMessage *)message;

@end

Intercept Messages Before and After Sending (Deprecated)​

tip

The RCIMSendMessageDelegate protocol has been deprecated as of SDK 5.3.5.

When IMKit sends a message, you can intercept it via delegate listeners. Set the delegate only once globally.

Your class must conform to the RCIMSendMessageDelegate protocol.

Set the delegate:

[RCIM sharedRCIM].sendMessageDelegate = self;
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