Simple logger for Godot Game Engine (godotgameengine.org)

logger.gd

# GodotLogger by Spooner
# ======================
#
# logger.gd is a simple logging system. It allows for more formatted logging,
# logging levels and logging to a file.
#
# Installation
# ------------
#
#     Place this file somewhere (for example, 'res://root/logger.gd')
#     and autoload it (in project settings) to make it into a globally accessible singleton.
#
# Logger levels
# -------------
#
#     Level.DEBUG - Show all log messages
#     Level.INFO - Show info(), warning(), error() and critical() log messages [DEFAULT]
#     Level.WARNING - Show warning(), error() and critical() log messages
#     Level.ERROR - Show error() and critical() log messages
#     Level.CRITICAL - Show only critical() log messages
#
# Time formats
# ------------
#
#     TimeFormat.NONE
#     TimeFormat.DATETIME [YYYY-MM-DD HH:MM:SS.mmm]
#     TimeFormat.TIME [HH:MM:SS.mmm]
#     TimeFormat.ELAPSED [H:MM:SS.mmm]
#
# Examples
# --------
#
#     Getting a reference to the global logger object with:
#         var logger = get_node('/root/logger')
# 
#     Setting the logger level (default is Level.INFO):
#         logger.level = logger.Level.DEBUG
#
#     Setting whether to print() message (default is to print):
#         logger.print_std = false
#
#     Setting showing the current elapsed time (defaults to show TimeFormat.DATETIME):
#         logger.time_format = TimeFormat.ELAPSED
#
#     Setting time formatter to use your own function (which would normally be called as my_instance.time_formatter()):
#         logger.time_format_func = funcref(my_instance, "time_formatter")
#
#     Logging to a file (set to 'null' to close the file):
#         logger.filename = 'user://log.txt'
#        
#     Logging messages of various types (will use var2str() to output any non-string being logged):
#         logger.info("Creating a new fish object")
#         logger.debug([my_vector3, my_vector2, my_list])
#         logger.warning("Tried to take over the moon!")
#         logger.error("File doesn't exist, so I can't go on")
#         logger.critical("Divided by an ocelot error! Segfault immanent")
#
# License: MIT

extends Node

# Levels of debugging available
class Level:
    const DEBUG = 0
    const INFO = 1 # default
    const WARNING = 2
    const ERROR = 3
    const CRITICAL = 4

# Built in time formatters
class TimeFormat:
    const NONE = 0
    const ELAPSED = 1
    const TIME = 2
    const DATETIME = 3 # default

# Print to stdout?
var print_stdout = true setget set_print_stdout, get_print_stdout
func get_print_stdout():
    return print_stdout
func set_print_stdout(value):
    assert(value in [true, false])
    print_stdout = value

# Logging level.
var level = Level.INFO setget set_level, get_level
func get_level():
    return level
func set_level(value):
    assert(level in [Level.DEBUG, Level.INFO, Level.WARNING, Level.ERROR, Level.CRITICAL])
    level = value

# Logging to file.
var file = null
var filename = null setget set_filename, get_filename
func get_filename():
    return filename
func set_filename(value):
    if file != null:
        info("Stopped logging to file: %s" % filename)
        file.close()

    if value != null:
        file = File.new()
        filename = value
        file.open(filename, File.WRITE)
        info("Started logging to file: %s" % filename)
    else:
        file = null
        filename = null  

# Log timer
var time_format_func = funcref(self, "format_time_datetime") setget set_time_format_func
func set_time_format_func(value):
    time_format_func = value

var time_format = TimeFormat.DATETIME setget set_time_format
func set_time_format(value):
    if value == TimeFormat.NONE:
        self.time_format_func = funcref(self, "format_time_none")
    elif value == TimeFormat.DATETIME:
        self.time_format_func = funcref(self, "format_time_datetime")
    elif value == TimeFormat.TIME:
        self.time_format_func = funcref(self, "format_time_time")
    elif value == TimeFormat.ELAPSED:
        self.time_format_func = funcref(self, "format_time_elapsed")
    else:
        assert(false) # Bad time format used.

# --- Time formatters for use by the logger.

func format_time_none():
    return ""
    
func format_time_elapsed():
    return "[%s] " % _format_elapsed()

func format_time_time():
    return "[%s] " % _format_time()

func format_time_datetime():
    return "[%s %s] " % [_format_date(), _format_time()]

# --- General time formatting functions

func _format_time():
    """Not used directly, but might come in useful"""
    var time = OS.get_time()
    # This is not "correct", but gives impression of ms moving on!
    var ms = OS.get_ticks_msec() % 1000

    return "%02d:%02d:%02d.%03d" % [time["hour"], time["minute"], time["second"], ms]

func _format_elapsed(time):
    """Not used directly, but might come in useful"""
    var time = OS.get_ticks_msec()
    var ms = time % 1000
    var s = int(time / 1000) % 60
    var m = int(time / 60000) % 60
    var h = int(time / 3600000)

    return "%d:%02d:%02d.%03d " % [h, m, s, ms]
func _format_date():
    """Not used directly, but might come in useful"""
    var date = OS.get_date()

    return "%d-%02d-%02d" % [date["year"], date["month"], date["day"]]

# --- Message writing methods

func debug(data):
    """Debugging message"""
    if level == Level.DEBUG:
        _write('DEBUG:', data)

func info(data):
    """Informational message"""
    if level <= Level.INFO:
        _write('INFO:', data)

func warning(data):
    """Warning message"""
    if level <= Level.WARNING:
        _write('WARN:', data)

func error(data):
    """Error message"""
    if level <= Level.ERROR:
        _write('ERROR:', data)

func critical(data):
    """Critical error message"""
    _write('CRIT:', data)

func _write(type, data):
    """Actually write out the message string"""
    if typeof(data) != TYPE_STRING:
        data = var2str(data)

    var message = '%s%5s %s' % [time_format_func.call_func(), type, data]

    if print_stdout:
        print(message)

    if file != null:
        file.store_line(message)

Thank you for this, it's exactly what I was looking for. Just FYI, I got a couple of errors on Godot 3.2.3.stable.mono. I'm assuming that this works for an earlier version.

res://addons/logger.gd:156 - Parse Error: Variable "time" already defined in the scope (at line 154).
res://addons/logger.gd:95 - Parse Error: The member "filename" already exists in a parent class.

I made a fork and fixed these for myself. I wasn't 100% sure about the first error, but it seems to be working with the edit I made. If you want those changes, feel free to pull them. (I'm haven't used gist.github before, so I'll leave that to you :-) ) Thanks!

Hi!

• The 'var time' in the function tries to recreate the 'time' parameter. You are correct to remove the parameter. If you look, the call to tge function already doesn't pass a parameter. Bad testing on my part, rather than changes to godot...
• Filename/file_name seems to be new.

Honestly, I'm amazed that there isn't a decent logging system built into godot by now!