Nice and simple logging. There are eight messages for logging based on severity. These correspond to the eight levels defined in syslog:
7 - debug (Debug-level messages)
6 - info (Informational)
5 - notice (Normal but significant Condition)
4 - warning (Warning Condition)
3 - err (Error Condition)
2 - crit (Critical Conditions)
1 - alert (must be handled immediately)
0 - emerg (System is unusable)
The absolutely easiest way to log is like this:
SLLog warn: 'Oopsidaisy'
...this utilizes the class SLLog as a facade onto a singleton that you reach with "SLLog instance". You can also register an instance in global #Log like:
SLLog useGlobalLog: true
...and then you can use:
Log warn: 'Hey, nicer to type!'
We only need to include the actual message in the string, timestamp etc is added automatically.
You can also explicitly supply a "sender" object which can be anything you like, a symbol or a specific domain object even:
SLLog warn: 'Yowsa' sender: #email
SLLog uses printString on the sender when producing the log entry, so if you use domain objects - make sure they have a unique printOn: method defined so that you can distinguish them. See class side category "logging" and "logging shorthand" for the available log messages.
By default there is a single emitter registered that logs on Transcript, you can turn this default initialization off (for new SLLog instances) with:
SLLog useTranscript: false
You can also use addTranscript/removeTranscript, addMorphic/removeMorphic etc to add and remove known emitters:
SLLog removeTranscript; addMorphic; addSyslog
The above removes default transcript emitter and adds an SLLogMorph as an emitter (and opens it), and also a SLSyslogSender emitter that will log onto localhost using UDP on port 514, see its class comment for details.
You can set a threshold for the syslog levels that should be logged onto Transcript (levels <= threshold are logged) using:
SLLog transcript transcriptMaxLevel: 4
...and you can set a threshold for raising a notifier (debugger) using:
SLLog instance notifierMaxLevel: 3
...or set a global threshold for all emitters:
SLLog instance globalMaxLevel: 4
Global flushing of all emitters can be done using "SLLog flush" and should ideally be called regularly by some background process.
Finally take a look at SLLogFile for details on how to add it as an emitter to get logging onto file instead of Transcript.