Cocoa Lumberjack: how to show file and line number?
Well, like I said, there is no built-in way. So, I've implemented custom formatter:
@interface LineNumberLogFormatter : NSObject<DDLogFormatter>
- (NSString *)formatLogMessage:(DDLogMessage *)logMessage;
@end
@implementation LineNumberLogFormatter
- (NSString *)formatLogMessage:(DDLogMessage *)logMessage
{
NSString *path = [NSString stringWithCString:logMessage->file encoding:NSASCIIStringEncoding];
NSString *fileName = [path lastPathComponent];
return [NSString stringWithFormat:@"%@:%d %@", fileName, logMessage->lineNumber, logMessage->logMsg];
}
@end
While a separate formatter class would work, it would make your logging code a bit more verbose. In my project I opted for adding some additional macros that make use of CocoaLumberjack like so:
// Prefix.pch file
// ...
#ifdef DEBUG
#define DLogError(fmt, ...) DDLogError((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#define DLogWarn(fmt, ...) DDLogWarn((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#define DLogInfo(fmt, ...) DDLogInfo((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#define DLogDebug(fmt, ...) DDLogDebug((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#define DLogVerbose(fmt, ...) DDLogVerbose((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#else
#define DLogError(fmt, ...)
#define DLogWarn(fmt, ...)
#define DLogInfo(fmt, ...)
#define DLogDebug(fmt, ...)
#define DLogVerbose(fmt, ...)
#endif
In your client code, you could then call:
DLogWarn(@"This is a warning");