[Catalyst] create controller helper

[Kiffin Gish]

Turns out that make_immutable doesn't always return a true value:

---start---
Couldn't load class (I4::Web) because: I4/Web/Controller/Auth.pm did not
return a true value at /usr/local/share/perl/5.10.0/Catalyst/Utils.pm
line 281.
Compilation failed in require
at /home/kiffin/perl5/lib/perl5/i486-linux-gnu-thread-multi/Class/MOP.pm
line 98.

at /home/kiffin/perl5/lib/perl5/i486-linux-gnu-thread-multi/Class/MOP.pm
line 102
        Class::MOP::__ANON__('I4/Web/Controller/Auth.pm did not return a
true value at /usr...') called
at /usr/local/share/perl/5.10.0/Try/Tiny.pm line 66
        Try::Tiny::try('CODE(0x9393f78)', 'CODE(0x9c9b770)') called
at /home/kiffin/perl5/lib/perl5/i486-linux-gnu-thread-multi/Class/MOP.pm
line 107
        Class::MOP::load_first_existing_class('I4::Web') called
at /home/kiffin/perl5/lib/perl5/i486-linux-gnu-thread-multi/Class/MOP.pm
line 118
        Class::MOP::load_class('I4::Web') called
at /usr/local/share/perl/5.10.0/Catalyst/ScriptRole.pm line 61

Catalyst::ScriptRole::_run_application('Catalyst::Script::Server=HASH(0x9fe8af8)') called at /usr/local/share/perl/5.10.0/Catalyst/Script/Server.pm line 181

Catalyst::Script::Server::run('Catalyst::Script::Server=HASH(0x9fe8af8)') called at /home/kiffin/perl5/lib/perl5/i486-linux-gnu-thread-multi/Class/MOP/Method/Wrapped.pm line 48

Class::MOP::Method::Wrapped::__ANON__('Catalyst::Script::Server=HASH(0x9fe8af8)') called at /home/kiffin/perl5/lib/perl5/i486-linux-gnu-thread-multi/Class/MOP/Method/Wrapped.pm line 89

Catalyst::Script::Server::run('Catalyst::Script::Server=HASH(0x9fe8af8)') called at /usr/local/share/perl/5.10.0/Catalyst/ScriptRunner.pm line 20
        Catalyst::ScriptRunner::run('Catalyst::ScriptRunner', 'I4::Web',
'Server') called at script/i4_web_server.pl line 8
---end---

If I add "1;" after make_immutable it all loads just fine. Am I doing
something wrong?


On Sat, 2010-01-09 at 15:26 +0000, Tomas Doran wrote:
> On 9 Jan 2010, at 11:35, Kiffin Gish wrote:
> 
> > Yes you're right, I overlooked the presence namespace::autoclean at  
> > the
> > top.
> >
> > Checked out the documentation but don't quite understand the  
> > difference
> > with namespace::clean. Is the latter the same as auto except then more
> > explicit in that only named -except methods aren't cleaned out?
> 
> namespace::clean removes any symbols from your package you haven't  
> explicitly specified at the end of your package, and ergo is ordering  
> dependent..
> 
> E.g.
> 
> package My::Example;
> use Test::More;
> use Acme::UNIVERSAL::cannot;
> use Foo qw/foo/;
> use Bar qw/bar/;
> use namespace::clean;
> use Quux qw/quux/;
> 
> ok __PACKAGE__->can('foo');
> ok __PACKAGE__->can('bar');
> ok __PACKAGE__->can('baz');
> 
> 1;
> # Cleaning happens at end of scope, i.e. lib/My/Example.pm finishes
> 
> package main;
> use My::Example;
> use Test::More;
> use Acme::UNIVERSAL::cannot;
> 
> ok My::Example->can't('foo');
> ok My::Example->can't('bar');
> ok My::Example->can('quux');
> 
> done_testing;
> 
> Note that the 'quux' symbol is not removed ever :)
> 
> namespace::autoclean uses a different mechanism to work out what to  
> clean - rather than being ordering related, at the end of your  
> package, it goes through the symbol table and finds all code symbols  
> in your package. It then gets the method list from Moose and works out  
> the set of symbols in your package which Moose doesn't consider a  
> method - if they're not methods, then they're imported functions...  
> The remaining list of imported functions is then removed..
> 
> Does this explanation make sense at all? Any chance you could make a  
> doc patch for namespace::clean and/or namespace::autoclean to make  
> this more clear?
> 
> > Also, when use Moose is used, is it no longer necessary to end the pm
> > module with a "1;"?
> 
> It is never necessary to end a .pm with 1;
> 
> You end with _any true value_. So you can end your package with:
> 
> 42;
> __PACKAGE__;
> 'ILIKECAKE';
> bless {}, 'FooBar';
> 
> or anything else you'd like to which is a true value.
> 
> The make_immutable method on Class::MOP::Class returns the newly  
> immutable metaclass instance.. Which is a true value :)
> 
> Cheers
> t0m
> 
> 
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-- 
Kiffin Gish <Kiffin.Gish at planet.nl>
Gouda, The Netherlands