Re: Core module: Attribute::Handlers behaviour

[enigma]

Hello PerlMonks,

I understand the trick "BrowserUk" has suggested. I tried to implement the same as below but it is always giving me error as

Can't locate object method "new" via package "Module"

Module.pm

package Module;
use Attribute::Handlers;

sub TRACE :ATTR(CODE,BEGIN) {
    my ($pkg, $sym, $ref, $attr, $data, $phase, $file, $line) = @_;
    *{ $sym } = sub {
        warn "$file($line) called with [@_]\n";
        my( @rc )= &$ref;
        warn "$file($line): returning [ @rc ]\n";
    }
}

sub new :TRACE{
    my $instance        = shift;
    my $class           = ref($instance) || $instance;
    my $self            = {};
    return bless($self, $class);
}
1;

Test.pl

#!/usr/local/bin/perl

my $module_to_load     = 'Module';
eval "use $module_to_load;";

# Create object
my $obj               = Module->new();

print "CLASS: " . ref($obj) ."\n";

When i'm changing the execution phase in ATTR to INIT,CHECK - module gets compiled successfully but ATTR TRACE is not called. And when i change the phase to BEGIN, I'm getting the above error message.

I need your help to understand why my Test.pl is not able to find "new()" method in Module.pm when Attribute::Handers are called at BEGIN phase.

Thanks

[Anonymous Monk]

I don't get that, even though your module doesn't return an object ( compared to Attribute::Constructor ), trace gets called if the phase is BEGIN

$ perl -le " eval qq/use Junk;/; print Junk->new "
Junk.pm(22) called with [Junk]
Junk.pm(22): returning [ Junk=HASH(0x3f8d1c) ]
1

$ cat Junk.pm
package Junk;
use Attribute::Handlers;

#~ sub TRACE :ATTR(CODE,CHECK) {
#~ sub TRACE :ATTR(CODE,INIT,CHECK) {
#~ sub TRACE :ATTR(CODE,INIT) {
sub TRACE :ATTR(CODE,BEGIN) {
#~ sub TRACE :ATTR(CODE) {
    my ($pkg, $sym, $ref, $attr, $data, $phase, $file, $line) = @_;
    *{ $sym } = sub {
        warn "$file($line) called with [@_]\n";
        my( @rc )= &$ref;
        warn "$file($line): returning [ @rc ]\n";
    }
}

sub new :TRACE {
    my $instance        = shift;
    my $class           = ref($instance) || $instance;
    my $self            = {};
    return bless($self, $class);
}
1;