Lost methods

Dave05 has asked for the wisdom of the Perl Monks concerning the following question:

OK, I'm on day 3 of trying to track down this one, so I'm turning to the Monks for some pointers.

This thing is a web site, running under HTML::Mason. I have a MyApp::Person object representing a logged in user. I can happily use the object to run through all the registered users in my database, and call methods to print out a list of names for instance.

But when I have a specific user logged in, and identified via a cookie, I get this error when trying to call methods off the user stored in the cookie (the cookie stores an ID string, which identifies a file on the server that holds the user data which is used to initialise the $user object):

Can't locate object method "full_name" via package "MyApp::Person" (perhaps you forgot to load "MyApp::Person"?)

Here's the thing. If I check %INC, MyAPP::Person _is_ loaded.
Also: ref($user) returns MyApp::Person
The next thing: if I run a $user->can('full_name'), it can't.
Next: in fact, my $user can't do _any_ of the MyApp::Person methods.
BUT: if I stick a dummy variable in MyApp/Person.pm (our $dummy_true = 1;), then I _can_ successfully read the dummy variable (via $MyApp::Person::dummy_true).

So basically, I can access the MyApp::Person namespace, but I can't use $user to get hold of any methods defined in there, despite ref($user) == MyApp::Person

One specific question I'd like to ask is: how can I check the package my code is currently running under?

But what I'd really like is suggestions as to where to look next.

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Re: Lost methods by Chmrr (Vicar) on Nov 26, 2002 at 12:32 UTC
As Abigail-II already pointed out, `__PACKAGE__` will tell you what package you're in. The only other, off-the-wall thought that I have is that your object reference is `bless`'d into class `"MyApp::Person\0"` somehow. This would explain why, for all intents and purposes, it `ref $user` says "MyApp::Person", but is unable to do anything that a MyApp::Person should be able to do. It's farfetched, but it's a possibility. perl -pe '"I lo`+$^X$\"$]!$/"=~m%(.)%s;$_=$1;y^`+*^e v^#$&V"+@( NO CARRIER'	[reply] [d/l] [select]
Re: Lost methods by Dave05 (Beadle) on Nov 26, 2002 at 15:16 UTC
++Chmrr! I haven't figured out yet where to look in the code for a \0 sneaking in, but I did this: `my $user = $session->param('user'); eval(Data::Dumper->Dump([$user], ['$user']));` [download] and $user started working! So it looks like there's something irregular getting tagged onto the end of the blessing, but only when the code is retrieved from the session. Well, I don't feel quite so bad that I couldn't track that one down! Cheers, D.	[reply] [d/l]
Re: Lost methods by Dave05 (Beadle) on Nov 26, 2002 at 15:04 UTC
perl -V says: Summary of my perl5 (revision 5.0 version 6 subversion 1) configuration: Platform: osname=solaris, osvers=2.8, archname=sun4-solaris I think 5.6.1. is OK? The code is a small component in my HTML:Mason site. Basically, it's a Perl subroutine embedded in an html page. Mason components run in the HTML::Mason::Commands namespace. This component should just spit out the user's name. Errors are caught by Mason and formatted as html, hence the <br />'s: use MyApp::Person; my $user = $session->param('user'); # CGI::Session my $name; eval{$name = $user->full_name} if $user; if ($@) { my $dump_user = Data::Dumper->Dump([$user], ['$user']); $dump_user =~ s\|,\|,<br />\|g; my $package = __PACKAGE__; my @methods = qw( ... all the methods from MyApp::Person ... ); my $check_methods; foreach my $method (@methods) { $check_methods .= sprintf "%s %s <br />", $user->can($method) +? 'CAN' : 'CANNOT', $method; } my $dummy = $MyApp::Person::dummy_true ? $MyApp::Person::dummy_tru +e : 'FALSE'; my $loaded_modules; foreach my $mod (sort values %INC) { $loaded_modules .= "$mod<br />"; } my $ref_user = ref($user); die "Current package: $package<br /> Dummy variable: $dummy<br /> \$user is a $ref_user<br /> $check_methods<br /> \@INC:<br /> $loaded_modules<br /> $dump_user<br />"; } else { [... do something with $name ...] } [download] The MyAPP was a typo ... All the things in the `die` statement check out - except all the methods come out CANNOT: `Current package: HTML::Mason::Commands Dummy variable: 1 $user is a Icapb::Person CANNOT new CANNOT _init CANNOT _check_user_type CANNOT _load_cv CANNOT ... etc etc etc @INC: ... /home/dave05/lib/perl5/mylib/MyApp/Person.pm ...` [download] and $user is initialised with all the appropriate data. I like Chmrr's suggestion. I develop in Win32, and run this thing on solaris, so maybe a bad line/file ending got in there somewhere, I'll check that out. I'm not sure how `use base` can help me? My Person object isn't derived from anything else. Thanks all, progress report soon!	[reply] [d/l] [select]
Re: Lost methods by Abigail-II (Bishop) on Nov 26, 2002 at 15:37 UTC
Well, according to your own code, `$user` is an instance of the `Icapb::Person` class. So, unless `Icapb::Person` inherits `MyApp::Person`, I'm not at all surprised you can't call those methods. Abigail	[reply] [d/l] [select]
Re: Re: Lost methods by Dave05 (Beadle) on Nov 26, 2002 at 16:06 UTC
Sorry, that's another typo, I've been changing the names to protect the innocent, and that slipped through.	[reply]
Re: Lost methods by fruiture (Curate) on Nov 26, 2002 at 12:20 UTC
Okay, although i have no idea what your problem really is, some diagnostics. The package you're in is in __PACKAGE__, but don't use it, create a function like "debug_whereami()" and let that function use caller(). Or easier: use Carp::croak(), it will give you all information. Here's the thing. If I check %INC, MyAPP::Person _is_ loaded. Wasn't it 'MyApp::Person'? In doubt, put a 'use MyApp::Person' in every file you need it. It's redundant, but Perl is a good language and require() will check %INC for you. Don't do this on your own, let perl do it. Now maybe this is really a bug, what does `perl -V` give you? Perhaps it's better to upgrade anyways... -- http://fruiture.de	[reply]
Re: Lost methods by Abigail-II (Bishop) on Nov 26, 2002 at 12:20 UTC
The answer to your specific question is: use `__PACKAGE__`. However, I'm not sure whether that will help you fixing your problem. Perhaps you show us the relevant code. Abigail	[reply] [d/l]
Re: Lost methods by mce (Curate) on Nov 26, 2002 at 12:25 UTC
Hi, The info you gave is rather limited, so I'll try to point you in the correct direction. I guess this is a base or ISA problem in your inheritance tree. Please check the `use base qw(Parent);` [download] Where Parent refers the the class (package) where the sub full_name is stored. use base uses and changes ISA a the same time. I hope this helps --------------------------- Dr. Mark Ceulemans Senior Consultant IT Masters, Belgium	[reply] [d/l]