Logger

 The Logger product defines the &LT;dtml-log&GT; DTML tag, allowing
 us to send messages to Zope's Log system from DTML. 

 Syntax

  'log' tag syntax::
    
    <dtml-log [severity=string] [subsystem=string] [exception]>
	[...]
    [<dtml-logdetail>]
	[...]
    </dtml-log>

    The 'log' and 'logdetail' sections can contain arbitrary DTML, which
    is parsed and sent to the Zope logging subsystem.

 Attributes

  severity=string -- Message severity passed to the Zope logging subsystem. 
		     It is case insensitive, and can be one of:

    BLATHER -- Somebody shut this app up.

    TRACE

    DEBUG

    INFO    -- For things like startup and shutdown.

    PROBLEM -- This isn't causing any immediate problems, but 
	deserves attention.

    WARNING -- A wishy-washy alias for PROBLEM.

    ERROR   -- This is going to have adverse effects.

    PANIC   -- We're dead!

  subsystem=string -- Any string of your choosing, used to help identify where
		      log messages originated from

  exception -- If set, the exception currently being handled is formatted
               (including the full traceback) and appended to the details 
	       of the message. This attribute has no effect if an exception
	       is not being handled.

 Note that depending on your current Zope logging system, some parameters
 may not be used and low severity messages may be silently dropped.  
 For example, when using Syslog logging as documented in doc/LOGGING.txt, 
 the subsytem parameter and the logdetail messages appear to have no effect, 
 and BLATHER severity messages are silently dropped.
 
 Examples

  eg::

   <dtml-log>Log this mesage!</dtml-log>

   <dtml-log severity=INFO subsystem=MyApp>
      This is some logged text!
   <dtml-logdetail>
     This is the detail section of the log.
     See doc/LOGGING.txt for details.
   </dtml-log>

   <dtml-log severity=blather>Current namespace: <dtml-var id></dtml-log>

   <dtml-try>
     [...]
   <dtml-except>
     <dtml-log severity=ERROR exception>
	Error doing stuff, so here is the traceback as well
     </dtml-log>
   </dtml-except>

 Transactions

  Even if a Zope transaction is aborted, log tags that have already been
  parsed will have been sent to the Logging system and will not be rolled
  back. This is desirable, as it makes this tag useful for debugging
  DTML code. 

 Author, Licence & Disclaimer

  This software was written by Stuart Bishop 
  "&LT;zen@shangri-la.dropbear.id.au&GT;", mailto:zen@shangri-la.dropbear.id.au
  11 Oct 1999 and is released under a BSD style licence. The author
  makes no promises as to the suitability of this software for any
  purpose whatsoever and can not be held liable for any direct or
  indirect effects of its use, including but not limited to spontaneous
  human combustion.

  Updates to this software will be made available on
  "Zope.org", http://www.zope.org/Members/Zen/Logger/.

  *$Id: README.txt,v 1.6 2002/04/22 04:28:34 zen Exp $*


