Minimal logging library for Clojure
I don't like clojure.contrib.logging. I like even less log4j and the rest of Java logging paraphernalia. I just want to log.
I like to log to standard error output (read this to get an idea of why) so that's the default for justlogit.
There are six log levels:
trace. For each one
there are two macros named
level-t. To the first style macros you pass
arguments as in
clojure.core/format. To the second class of macros, you pass a
Throwable as first argument.
(fatal "A bad thing happened: %s, aborting" (get-bad-thing))
will output something like
FATAL 2011-04-05T19-55-06.859 [your-ns]: A bad thing happened: bad thing, aborting
If you want to log a
Throwable instance, use:
(try (danger) (catch Exception e (warn e "So, what now")))
Which will produce something like
WARN 2011-04-05T19-55-06.859 [your-ns]: So, what now java.lang.Exception: transaction rolled back: foooooo at clojure.contrib.sql.internal$throw_rollback.invoke (internal.clj:142) clojure.contrib.sql.internal$transaction_STAR_.invoke (internal.clj:169) ..... .....
If you don't want the defaults you can customize the behaviour using both context macros and global setters:
(set-log-level :warn) ; warn is set as minimum log level globally. ; calls of lower priority won't be logged (nor evaluated) (with-log-level :warn ;inside this context the minimum log level is set to :warn (do-your-thing)) ;and everything is back to normal now (set-log-writer my-writer) ;sets the global OutputStreamWriter to use for logging (with-log-writer my-writer (do-your-thing)) ;scoped writer
You can also customize the log format, using a function that returns the logged string.
This function takes a map with keys:
:throwable (optional Throwable instance)
;set a new formatter globally (set-log-formatter #(str "Broken: " (:message %))) ;scoped formatter (with-log-formatter #(str "Broken: " (:message %)) (debug "I'm here"))
Copyright (C) 2011 Sebastián Galkin
Distributed under the Eclipse Public License, the same as Clojure.