Subclassing L4P appears to generate fixed category log messages

Hi there fellow monasterians ,

I appear to have encountered an unexpected problem whilst trying to extend Log::Log4perl by way of subclassing it as in (simple form) ...

#! /usr/bin/env perl

package L4P::Subclass;

use Log::Log4perl qw/:no_extra_logdie_message :levels/;
our @ISA = qw/Log::Log4perl/;
Log::Log4perl->wrapper_register( __PACKAGE__ );
Log::Log4perl->easy_init(
    {
        name        => 'LOG',
        file        => "STDOUT",
        layout      => '[%d - %r] %p (%c) %M:%L %m%n',
        level       => $TRACE,
    }
) or die 'easy_init() failed - ';

sub new {
    my $pkg = shift;

    my $log = bless Log::Log4perl->get_logger(caller()), __PACKAGE__;

    warn $log->get_logger(caller())->category();

    return $log;
}

sub trace_start {
    my $self = shift;

    $self->debug("Starting with args: " . join ', ', @_);
}

#our $AUTOLOAD;
sub AUTOLOAD {
    my $self = shift;
    (my $method = $AUTOLOAD) =~ s/.*://;
    Log::Log4perl->get_logger(caller())->$method(@_);
}

package main;

my $log = L4P::Subclass->new();

$log->trace_start("Please don't let it be L4P::Subclass");
[download]

However, when the script is run, the output is

L4P.Subclass at work/repos/Git/tools/lib/IBM-PTC-Core/LogTest.pl line 
+22.
[2013/02/20 14:22:48 - 1] DEBUG (L4P.Subclass) main:::44 Starting with
+ args: Please don't let it be L4P::Subclass
[download]

- the, not necessarily clear, problem is that although the package name and line number are correct (as in main::44), the category of the logged message is always L4P.SubClass c/w the expected value of main.

Question is, have I done something wrong in my code or is there actually something wrong ?

As always, any help &/or hints will be gratefully received.

TIA & rgds ,

A user level that continues to overstate my experience :-))

Comment on Subclassing L4P appears to generate fixed category log messages Select or Download Code
Re: Subclassing L4P appears to generate fixed category log messages by zwon (Monsignor) on Feb 23, 2013 at 13:55 UTC
Your problem starts here: `my $log = bless Log::Log4perl->get_logger(caller()), __PACKAGE__;` [download] You're subclassing `Log::Log4perl` package, but in constructor you're creating `Log::Log4perl::Logger` object and reblessing it into `L4P::Subclass`. I think you should in `L4P::Subclass` implement your own get_logger method which will return `L4P::Subclass::Logger` object. Later in `AUTOLOAD` you're ignoring this logger object and creating a new one: `Log::Log4perl->get_logger(caller())->$method(@_);` [download] but `AUTOLOAD` is called from your package from `trace_start`, so category is "L4P.Subclass" and not main. You can replace it with `caller(1)` or just use `get_logger()` as `Log::Log4perl` will automatically skip frames belonging to your module because you've registered it as wrapper. But in order this to work you should also fix the constructor, something as simple as: `sub new { return bless {}, shift; }` [download] will do the thing, reblessing Logger object into `L4P::Subclass` somehow confuses Log4perl and `AUTOLOAD` invokes itself recursively. PS: also note, that you can create custom log levels. I can't find documentation, but the code is in Log::Log4perl::Logger	[reply] [d/l] [select]
Re^2: Subclassing L4P appears to generate fixed category log messages by Bloodnok (Vicar) on Feb 27, 2013 at 13:14 UTC
TFT, I take your point about the call to `bless()` - I came to the same conclusion as yourself and blessed an anon scalar into the Subclass - which appears to correct (or, at least) avoid the confusion to L4P. A user level that continues to overstate my experience :-))	[reply] [d/l]


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Subclassing L4P appears to generate fixed category log messages

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