How do I create a Catalyst::Model::DBIC::Schema from a DBIC::Schema? - perl

Question

Total lack of documentation makes this difficult..
Essentially, I have
package MyApp::Schema;
sub new_schema {
__PACKAGE__->connect(...)
}
Then I have
package MyCatApp::Model::MyApp;
use Moose;
extends 'Catalyst::Model::DBIC::Schema';
## what here;
_PACKAGE__->make_immutable;
How do I make this work? If I have this in my config...
<Model::MyApp>
schema_class MyApp::Schema
traits Caching
user_defined_schema_accessor foo
</Model::MyApp>
I get the following error:
BEGIN failed--compilation aborted at MyCatapp.psgi line 4, line 1.
Error while loading MyCatapp.psgi: Couldn't instantiate component "Either ->config->{connect_info} must be defined for MyCatApp::Model::MyApp or MyApp::Schema must have connect info defined on it.
But adding sub connect_info {} in MyApp::Schema does not change anything. That error is generated on line 480 of this file.
That method seems to be looking at $schema_class->storage->connect_info which I believe is an method on an instantiated object, and not a function in the package. However, if I try to set
__PACKAGE__->config('schema_class', MyApp::Schema->new_schema)
I then get...
Error while loading : Couldn't instantiate component "MyCatApp::Model::MyApp", "Attribute (schema_class) does not pass the type constraint because: Validation failed for 'Catalyst::Model::DBIC::Schema::Types::SchemaClass' with value MyApp::Schema=HASH(0xb4a5ff0) at /usr/local/lib/perl/5.18.2/Moose/Exception.pm line 37
So, how do I go about doing this...

Answer 1

So.. I'm not sure this is right so I won't mark it as accepted but I was pretty damn close.. This line is dead on..
__PACKAGE__->config('schema_class', MyApp::Schema->new_schema)
And the code is in place for that to work, as per the link above on line 480 of Catalyst::Model::DBIC::Schema. However, the type is wrong..
The type of schema_class is SchemaClass. And, SchemaClass is defined here
subtype SchemaClass,
as LoadableClass,
where { $_->isa('DBIx::Class::Schema') };
Now, SchemaClass is a subtype of a MooseX::Types::LoadableClass which essentially just takes a package name and requires it..
The problem is LoadableClass doesn't take an instance of DBIC::Schema. Anyway.. I was just changed it too..
has schema_class => (
is => 'ro',
isa => 'Object',
required => 1
);
Now I can stuff an instantiated schema into schema_class and pass the conditional if($schema_class->storage && $schema_class->storage->connect_info).
I filed a bug on this here

Answer 2

You could instantiate the connection info in your MyApp::Schema by in it doing:
__PACKAGE__->connection(#your_connection_details);
This will set up a Storage on the class itself, not a schema object. This will then pass the Catalyst::Model::DBIC::Schema check and work successfully. I think this achieves what you're after without changing the underlying classes (though might depend on the details not included).

Answer 3

From the documentation you referenced, your MyCatApp::Model::MyApp would look like this:
__PACKAGE__->config(
schema_class => 'MyApp::Schema',
connect_info => {
dsn => 'dbi:Pg:dbname=mypgdb',
user => 'postgres',
password => '',
pg_enable_utf8 => 1,
on_connect_do => [
'some SQL statement',
'another SQL statement',
],
}
);
And in your controller, you would:
my $db = $c->model('MyApp');