gistfile1.m

/* MSHandler.m */

// Dispatched as soon as the synchronization progresses
// In this method we set "shouldKeepCallback" as YES since the sync is still in progress
- (void)didSyncWithProgress:(NSNumber *)current total:(NSNumber *)total {
    int percent = 100 * [current floatValue] / [total floatValue];
    [self.plugin returnSyncStatus:@""
                           status:2
                         progress:percent
                         callback:self.callback
               shouldKeepCallback:YES];
}

// Dispatched when a synchronization is completed
// In this method we set "shouldKeepCallback" as NO since the sync has already ended
- (void)scannerDidSync:(MSScanner *)scanner {
    MSDLog(@" [MOODSTOCKS SDK] SYNC SUCCEEDED (%d IMAGE(S))", [scanner count:nil]);
    [self.plugin returnSyncStatus:@""
                           status:3
                         progress:100
                         callback:self.callback
               shouldKeepCallback:NO];
    
    [self release];
}

//...

/* MoodstocksPlugin.m */

// Sync status callback
- (void)returnSyncStatus:(NSString *)message
                  status:(int)status
                progress:(int)progress
                callback:(NSString *)callback
      shouldKeepCallback:(BOOL)shouldKeepCallback {

    // Collect different sync indicators in a NSDictionary
    // Including the boolean for "should keep callback"
    NSDictionary *statusDict = [NSDictionary dictionaryWithObjectsAndKeys:message, @"message",
                                                                          [NSNumber numberWithInt:status], @"status",
                                                                          [NSNumber numberWithFloat:progress], @"progress",
                                                                          nil];
    
    CDVPluginResult *result = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK
                                                messageAsDictionary:statusDict];
    
    [result setKeepCallbackAsBool:shouldKeepCallback];
    
    NSString *js = [result toSuccessCallbackString:callback];
    [self writeJavascript:js];
}