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Agent::Tag(3)	      User Contributed Perl Documentation	 Agent::Tag(3)

NAME
       Log::Agent::Tag - formats caller	information

SYNOPSIS
	Intended to be inherited from

DESCRIPTION
       This class is meant to be inherited by all the classes implementing a
       log message tag.

       A message tag is	a little string	that is	either appended	or prepended
       to all log messages.

       For instance, and oversimplifying a bit,	a tag meant to be prepended
       will be inserted	in front of the	current	log message, separated by
       separator, which	defaults to a single space:

	  +------------+-----------+---------------------------------+
	  | tag	string | separator |	  current log message	     |
	  +------------+-----------+---------------------------------+

       This operation is called	tag insertion. The whole string	then becomes
       the current log message,	and can	be the target of another tag
       insertion.

       The reality is a	little bit more	complex, to allow successive tags to
       be prepended or appended	in the order they are specified, and not in
       reverse order as	they would be if naively implemented.  See
       Log::Agent::Message for the exact semantics of append() and prepend()
       operations.

FEATURES
       This section documents the interface provided to	heirs, in case you
       wish to implement your own tag class.

       _init(name, postfix, separator)
	   Initialization routine that should be called	by all heirs during
	   creation to initialize the common attributes.

       postfix
	   When	true, the tag is meant to be appended to the log message.
	   Otherwise, it is prepended.

       name
	   The name of this tag.  It is	meant to provide by-name access	to
	   tags, check whether a given tag is recorded,	etc...	The names
	   "caller" and	"priority" are architecturally defined to refer	to
	   "Log::Agent::Tag::Caller" and "Log::Agent::Tag::Priority" objects.

	   NOTE: Currently unused by any client	code.

       separator
	   The sperating string	inserted between the tag and the log message.
	   It defaults to " " if not specified,	i.e. left to "undef" when
	   calling _init().

       string()
	   A deferred routine, to be implemented by heirs.

	   Returns the tag string only,	without	the separator, since its exact
	   placement depends on	the value of the "postfix" attribute.

       insert(message)
	   Insert this tag withing the "Log::Agent::Message" message,
	   according to	the tag	specifications (placement, separator).	Calls
	   string() to produce the tag string.

	   This	routine	is frozen and should not be redefined by heirs.

STANDARD TAGGING CLASSES
       Tagging classes define via their	"string()" routine what	is the string
       to be used as a tag.  The insertion of the tag within the log message
       is done via a frozen routine from the "Log::Agent::Tag" ancestor.

       The following classes are provided by "Log::Agent":

       "Log::Agent::Tag::Callback"
	   The "string()" routine invokes a user-supplied callback, given as a
	   "Callback" object.  You need	the Callback module from CPAN if you
	   wish	to use this class.

       "Log::Agent::Tag::Caller"
	   Used	internally to compute the caller and format it according to
	   user	specifications.

       "Log::Agent::Tag::Priority"
	   Used	internally to format message priorities	and add	them to	the
	   log messages.

       "Log::Agent::Tag::String"
	   Defines a constant tagging string that should be added in all the
	   log messages, e.g. a	web session ID.

AUTHOR
       Raphael Manfredi	_Raphael_Manfredi@pobox.com_

SEE ALSO
       Log::Agent::Message(3).

perl v5.32.0			  2017-10-27			 Agent::Tag(3)

NAME | SYNOPSIS | DESCRIPTION | FEATURES | STANDARD TAGGING CLASSES | AUTHOR | SEE ALSO

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