[Catalyst] Going through tutorial, part 2 and getting error

[Alejandro Imass]

Does this give you any clues?
Can't locate MyAppDB/Customer.pm

Ok here is how it goes, I suspect you are using DBIx::Class

app from here on stands for the name your app, of course

You should have a Model class in your lib/app/Model/appDB.pm which
should be based on Catalyst::Model::DBIC::Schema

In this file, you will have config method where you specify the
connection parameters and the actual class that maps you DB objects.
Generally you can use the same name for the actual DB class, but with
another namespace (the actual schema mapper class will usually be
sitting directly in the lib/ directory).

In the schema mapper class, say lib/appDB.pm you will see that it is
based on DBIx::Class::Schema, here you should have a load_classes
method implemented with your tables as such:

# Cargar clases de DBIC
__PACKAGE__->load_classes({
    vdcDB => [qw/
	      creadores
	      vida_creador
	      categorias
	      sub_categorias
[...]

Each entry will correspond to an individual ORM class in the appDB
subdirectory sitting right there in your main lib directory.

Each ORM class will derive from DBIx::Class directly and implement
your actual M class. Later in you C code you do stuff like:

    $c->stash->{subcats_creador} = [$c->model('vdcDB::sub_categorias_creadores')
				    ->search(
					     {
						 id_creador => $id,
					     },
					     {
						 join => {'sub_categorias' => 'categorias'},
						 prefetch => {'sub_categorias' => 'categorias'},
					     },
					     )];

Which of course will put any Rails or PHP programmer to shame ;-] (in
fact don't know of any other ORM technology that can actually do this)

Here is a sample ORM class for your enjoyment. SPECIAL NOTE: I have
read about autoloading features of DBIx and generating the DB from the
ORM and vice versa. My recommendation is that DBIx::Class is so
powerful that defining you mappings by hand is by far the best method
(besides the fact that is very easy). There is nothing better like
good and sound database modeling (decent normalization, referential
integrity, default values, etc.) and then good and sound MANUAL ORM
mapping. Never try to push the ORM too far, even though DBIx::Class
can handle very complex things, it is usually best to resolve
complicated stuff in the DB with a View or Rule (if you're lucky or
smart enough to be working with PostgreSql ;-] ) If you actually
exploit a REAL ORDBMS (like Postgres, not the fake ones like Oracle)
things with a powerful ORM like DBIx::Class can get pretty
fascinating. Anyway, here's the example:

package vdcDB::sub_categorias;

use base qw/DBIx::Class/;

# Cosas requeridas de DBIC
__PACKAGE__->load_components(qw/PK::Auto Core/);
# Nombre de la tabla
__PACKAGE__->table('sub_categorias');
# Columnas de la tabla
__PACKAGE__->add_columns(qw/
			 id
			 id_categoria
			 nombre
			 descripcion
			 /);

# Clave primaria
__PACKAGE__->set_primary_key(qw/id/);

# relación clave foránea con categorías
__PACKAGE__->belongs_to(categorias => vdcDB::categorias, 'id_categoria');

# Relación 1..n con sub_categorias_creadores
__PACKAGE__->has_many(sub_categorias_creadores =>
'vdcDB::sub_categorias_creadores', 'id_sub_categoria');

1;

Perl. There is no substitute.

Alejandro Imass

P.S. Sorry about the spanish comments.


On Jan 6, 2008 2:59 AM, Andrew <archan2000 at yahoo.com> wrote:
> A newbie getting back into perl and decided to start using it w/ Catalyst.
>
> I'm going through the tutorial, part 2 and modifying it by changing the
> Models, and slightly different presentation, but the structure of the data
> is the same (e.g. instead of a Book object I'm using a Customer object, but
> it's the same in that a Book can have many authors, a Customer can have many
> credit cards). So I'm making the example more applicable to what I'd to use
> it for and basically renaming stuff.
>
> When I run "script/myApp_server.pl" I get the following error:
> "
> Couldn't instantiate component "register::Model::registerModel", "Cannot
> load schema class 'registerDB': DBIx::Class::Schema::throw_exception():
> Can't locate MyAppDB/Customer.pm in @INC (@INC contains:
> /mnt/hgfs/mac/Desktop/share/catalyst/webpage/apps/register/script/../lib
> /home/owner/local/lib/perl5 /home/owner/local/share/perl/5.8.8
> /home/owner/local/lib/perl/5.8.8 /home/owner/local/lib /etc/perl
> /usr/local/lib/perl/5.8.8 /usr/local/share/perl/5.8.8 /usr/lib/perl5
> /usr/share/perl5 /usr/lib/perl/5.8 /usr/share/perl/5.8
> /usr/local/lib/site_perl .) at (eval 110) line 3.
> Compilation failed in require at
> /usr/local/share/perl/5.8.8/Catalyst/Model/DBIC/Schema.pm line 271.
>  at script/register_server.pl line 53" at script/register_server.pl line 53
> Compilation failed in require at script/register_server.pl line 53.
> "
>
> Could I be running the helper scripts w/ the wrong arguments?  I know I have
> all the dependencies installed since I got the tutorial code from SVN,
> deployed in the same environment and it ran as expected.  I tried redoing it
> to see if I made any syntax mistakes and still same error message.  Any
> suggestions?
>
>
>
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