toddhopkinson/log

Debug Logging In Swift

Log

A solid, simple Swift debug logger that conditionally compiles logging functionality for DEBUG builds only.

Usage

To print a trace log:

Log.trace()
// [TRACE]filename:function():line

To log a custom message:

Log.debug("success!")
// [DEBUG]filename:function():line success!

Installation

1. Add the Log.swift file to your project.

2. Add the DEBUG flag. Open the target build settings, find 'Swift Compiler - Custom Flags' settings and under 'Other Swift Flags' add -DDEBUG next to Debug. When DEBUG isn't found, logging won't occur, e.g., in a Release build.

Design

Aim: To provide a simple, easy to use debug logger with the following characteristics:

• The logs print to the console precisely when expected and not indeterminately from some background thread.
• Code will not be executed nor parameters evaluated in the log function calls unless it is a DEBUG build, i.e., logs will never appear in Release builds.
• Interfaces are intuitive .
• Two types of logs can be printed to the console - trace and debug logs.
• In all cases logs print the filename, function name, and line number of the log invocation.