NAME

       Log::Agent::Tag::Callback - a dynamic tag string

SYNOPSIS

        require Log::Agent::Tag::Callback;
        # Inherits from Log::Agent::Tag.

        my $tag = Log::Agent::Tag::Callback->make(
            -name      => "session id",
            -callback  => Callback->new($obj, 'method', @args),
            -postfix   => 1,
            -separator => " -- ",
        );

DESCRIPTION

       This class represents a dynamic tag string, whose value is determined by invoking a pre-
       determined callback, which is described by a "Callback" object.

       You need to make your application depend on the "Callback" module from CPAN if you make
       use of this tagging feature, since "Log::Agent" does not depend on it, on purpose (it does
       not really use it, it only offers an interface to plug it in).  At least version 1.02 must
       be used.

CREATION ROUTINE PARAMETERS

       The following parameters are defined, in alphabetical order:

       "-callback" => "Callback" object
           The callback to invoke to determine the value of the tag.  The call is protected via a
           busy flag, in case there is an unwanted recursion due to a call to one of the logging
           routines whilst within the callback.

           If the callback is busy, the tag emitted is:

               callback "user" busy

           assuming "user" is the name you supplied via "-name" for this tag.

       "-name" => name
           The name of this tag.  Used to flag a callback as busy in case there is an unwanted
           recursion into the callback routine.

       "-postfix" => flag
           Whether tag should be placed after or before the log message.  By default, it is
           prepended to the log message, i.e. this parameter is false.

       "-separator" => string
           The separation string between the tag and the log message.  A single space by default.

AUTHOR

       Raphael Manfredi <Raphael_Manfredi@pobox.com>

SEE ALSO

       Callback(3), Log::Agent::Tag(3), Log::Agent::Message(3).