log4factorio:

Slim mod for logging inspired by log4j (but with much less functionality 😉).

This is intended as facility to be used in other mods - it doesn't add any feature to the played game.

Features

Offers the ability to add log statements which can be enabled/disabled by configuration at run time.
It supports the following log levels (AKA severities)

• FATAL
  use for logging severe errors
• ERROR
  use for logging major errors
• WARN
  use for logging minor errors
• INFO
  use for logging informational messages
• CONFIG
  use for logging informational messages concerning configuration
• FINE
  use for logging debug messages
• FINER
  use for logging more verbose debug messages
• FINEST
  use for logging very verbose debug messages

FATAL is the highest, FINEST the lowest log level. Let's say log level is configured to INFO, then only all
loggging calls with a level of INFO or higher (i.e. FATAL, ERROR, WARN and INFO) will be logged, all
others will produce no log entries.

Integration into other mods

1. include it with require

   local Log = require("__log4factorio__.Log")

2. set the desired log level, either

   • from configuration

   Log.setSeverityFromSettings("testmod1-logLevel")

   • or hard coded

   Log.setSeverity(Log.WARN)

3. if using configuration add the appropiate entries to the locale files resp. to settings.lua

   ```
   [mod-setting-name]
   testmod1-logLevel=choose log level

   [mod-setting-description]
   testmod1-logLevel=all calls with this log level or higher will be logged (FATAL is the highest, FINEST the lowest level)
   ```

   resp.

   data:extend({ { type = "string-setting", name = "testmod1-logLevel", order = "zz", setting_type = "runtime-global", default_value = "CONFIG", allowed_values = { "FATAL", "ERROR", "WARN", "INFO", "CONFIG", "FINE", "FINER", "FINEST", } }, })

   

   For more details please have a look at https://wiki.factorio.com/Tutorial:Mod_settings#Locale

4. Log something

   Log.log("sth happened", function(m)log(m)end, Log.INFO)

   Log.logLine( { ndx = ndx, wcid = wcid }, function(m)log(m)end, Log.FINE)

   Log.logBlock(data, function(m)log(m)end, Log.FINEST)

That produces entries in factorio-current.log like

137.987 Script @__testMod1__/control.lua:16: [FINE] sth happened

Hint: If you want to log to the factorio-current.log, use function(m)log(m)end instead of simply log. That offers
the advantage that the logged line number is that from the call in the mod using log4factorio and not the line number
from inside log4factorio, where log() is executed 😉.