CocoaLumberjack with Swift - Calling preprocessor macros

Question

I started to build an IOS app with the new programming language Swift. I managed to use CocoaPods and was able to successfully create the DDTTYLogger with my CustomLoggerFormatter (Objective-C) in my AppDelegate.swift and append it to the loggers.

var customLoggerFormatter = CustomLoggerFormatter()

var consoleLogger: DDTTYLogger = DDTTYLogger.sharedInstance()
consoleLogger.setLogFormatter(customLoggerFormatter)
DDLog.addLogger(consoleLogger)

But the problem is, that the CocoaLumberjack Library is using preprocessor macros for the logger methods like DDLogVerbose(@"..")

Which is defined in the DDLog.h:

#define DDLogVerbose(frmt, ...) LOG_OBJC_MAYBE(LOG_ASYNC_VERBOSE, LOG_LEVEL_DEF, LOG_FLAG_VERBOSE, 0, frmt, ##__VA_ARGS__)

Is there any workaround to make preprocessor defines work in Swift? Or did anyone try something similar with more success?

Answer 1

Okay, I just found a solution. Writing an Objective-C Wrapper class calling the preprocessors and offering methods to call it.

Hopefully this will help other people facing the same issues.

I first created a header file:

@interface DDLogWrapper : NSObject
+ (void) logVerbose:(NSString *)message;
+ (void) logError:(NSString *)message;
+ (void) logInfo:(NSString *)message;
@end

With the corresponding implementation:

#import <Foundation/Foundation.h>
#import "DDLogWrapper.h"

// Logging Framework Lumberjack
#import "DDLog.h"
#import "DDASLLogger.h"
#import "DDTTYLogger.h"

// Definition of the current log level
#ifdef DEBUG
static const int ddLogLevel = LOG_LEVEL_VERBOSE;
#else
static const int ddLogLevel = LOG_LEVEL_ERROR;
#endif

@implementation DDLogWrapper

+ (void) logVerbose:(NSString *)message {
    DDLogVerbose(message);
}

+ (void) logError:(NSString *)message {
    DDLogError(message);
}

+ (void) logInfo:(NSString *)message {
    DDLogInfo(message);
}

@end

Important is to add the DDLogWrapper.h File to the ProjectName-Bridging-Header.h file and then you are able to instantiate in Swift the DDLogWrapper and call the methods logVerbose, logError, logInfo..

With the following code I was able to make a log statement:

DDLogWrapper.logVerbose("TEST");

Answer 2

I created a Swift wrapper for CocoaLumberjack that encapsulates everything nicely.

DDLog.addLogger(DDTTYLogger.sharedInstance())
DDLog.logLevel = .Info

logInfo("Info")
logWarn("Warn")
logDebug("Debug")
logError("Error")

Answer 3

As of 2.0.0beta4, CocoaLumberJack includes a CocoaLumberJack.swift file that makes its integration with Swift projects really easily.

They use a global var defaultDebugLevel to set the DDLogLevel, and you can swift basic precompile macros to customize it to your needs.

#if DEBUG
    defaultDebugLevel = DDLogLevel.All
#else
    defaultDebugLevel = DDLogLevel.Warning
#endif

DDLog.addLogger(DDTTYLogger.sharedInstance())
DDLogDebug("Debug")
DDLogInfo("Info")
DDLogWarn("Warning")
DDLogVerbose("Verbose")
DDLogError("Error")