[Pythoncard-users] Logging

[Andy T. <an...@cr...>]

Evening all,

I was idly perusing the sample code (I do that on Friday nights, you 
know) and I discovered that none of the samples uses the logging module 
that is included in the prototype.

Determined to remedy this oversight I set about changing one of the 
samples and ten minutes later (beat that Kevin!), worldclock has been 
changed. The code in CVS has been updated and should be included in the 
next release.

If you are running it without a console window you will not notice any 
difference. If you have a console window the regular messages that used 
to be output are no longer. To get output you need to enable logging 
with the -l switch on the command line. Switch it on and all of the 
messages will be written to a file called pythoncard.log in the same 
directory as worlclock.py. Note that this file is overwritten each time 
you run the application, you have been warned!

Luckily the changes to the code were quite simple, just import the log 
class;

"""
from PythonCardPrototype.log import Log
"""

Then add a couple of lines to the __init__ method of your application class;

"""
self.log = Log.getInstance()
self.log.enableLevels( [ Log.ERROR, Log.WARNING, Log.DEBUG, Log.INFO ] )
"""

Then, when you want to output a message just use;

self.log.info( < whatever you need to output > )
or
self.log.debug( ... )
self.log.error( ... )
self.log.warning( ... )

When calling any of these methods you can (I'm told) include any number 
and combination of items (well, OK - objects), their 'repr' methods will 
be called to render them into a format suitable for writing to a file.

Note that I've enabled all of the log levels in the code, so running the 
sample application with -l you will see all of the messages that are 
output. As a general rule of thumb it is better to only enable ERROR and 
WARNING and to disable DEBUG and INFO.  When you are actively changing 
or developing a module turn these on but don't forget to turn them back 
off when you ship.

Regards,
Andy
-- 
-----------------------------------------------------------------------
 From the desk of Andrew J Todd esq.
"Shave my poodle!"