Logger

BasicLogger.swift

class BasicLogger: NSObject {
    private static let queue = dispatch_queue_create("com.vhart.BasicLoggerQueue", DISPATCH_QUEUE_SERIAL)
    private static let dateFormatter = NSDateFormatter()

    static var filePath: String {
        return fileUrl.path!
    }

    static var fileUrl: NSURL {
        let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
        let documentsDirectory = paths[0] as NSString
        return NSURL(fileURLWithPath: documentsDirectory.stringByAppendingPathComponent("LogFile.txt"), isDirectory: false)
    }

    override init() {
        fatalError()
    }
    
    // For Obj-C compatability
    //
    // Convert __FILE__ using [NSString stringWithFormat:@"%s", __FILE__
    // Same for __FUNCTION__
    //
    // [BasicLogger objcWriteFile: [NSString stringWithFormat:@"%s", __FILE__]
    //                   function: [NSString stringWithFormat:@"%s", __FUNCTION__]
    //                       line: __LINE__
    //                    message: @"Example message"];
    //
    class func objcWriteFile(file: String,
        function: String,
        line: Int,
        message: String) {
            objc_sync_enter(self)
            defer { objc_sync_exit(self) }
            let fileName = (file as NSString).lastPathComponent
            write("\(fileName) \(function): \(line): -- \(message)")
    }

    class func write(file: String = #file,
        function: String = #function,
        line: Int = #line,
        message: String) {
            objc_sync_enter(self)
            defer { objc_sync_exit(self) }
            let fileName = (file as NSString).lastPathComponent
            write("\(fileName) \(function): \(line): -- \(message)")
    }

    private class func write(str: String) {
        dispatch_async(queue) {
            dateFormatter.dateFormat = "MM-dd-yyyy'| 'HH:mm:ss +SSS'|'"
            let dateNow = NSDate()
            let content = "\(dateFormatter.stringFromDate(dateNow)): - \(str)\n"

            guard let data = content.dataUsingEncoding(NSUTF8StringEncoding) else { return }

            if NSFileManager.defaultManager().fileExistsAtPath(filePath) {
                do {
                    let fileHandler = try NSFileHandle.init(forWritingToURL: fileUrl)
                    fileHandler.seekToEndOfFile()
                    fileHandler.writeData(data)
                    fileHandler.closeFile()
                } catch {
                    print("could not write to file: \(error)")
                }
            } else {
                do {
                    try content.writeToFile(filePath, atomically: true, encoding: NSUTF8StringEncoding)
                } catch let error as NSError {
                    print("Could not create to file: \(error.localizedDescription)")
                }
            }
        }
    }
}