[Catalyst] Accessing DB from external model

[Octavian Rasnita]

From: "Mike Raynham" <catalyst at mikeraynham.co.uk>
> Hi,
>
> I am fairly new to all things Perl and Catalyst, and would like to know if 
> what I am attempting to do is correct.
>
> I've recently finished reading 'The Definitive Guide to Catalyst', which 
> has been very helpful, but I am still a little confused about separating 
> my business logic from my Catalyst application, and accessing the database 
> connection from my non-Catalyst application.
>
> At the moment, I have my external class in the lib/MyApp directory.  It 
> uses the connection info found in MyApp::Model::DB, like so:
>
> ---
>
> # lib/MyApp/MyExternalClass.pm
> MyApp::MyExternalClass
>
> use MyApp::Model::DB;
> use MyApp::Schema;
>
> my $connect_info = MyApp::Model::DB->config->{connect_info};
> my $schema = MyApp::Schema->connect( $connect_info );
>
> # Do stuff with $schema...
>
> ---
>
> That works, and I can connect to the database.  However, I have searched 
> this mailing list, and found this:
>
> http://www.mail-archive.com/catalyst@lists.scsys.co.uk/msg00817.html
>
> Here, the connection information is moved from MyApp::Model::DB to 
> MyApp::DB, and then Catalyst::Model::Adaptor is used to glue 
> MyApp::Model::DB to MyApp::DB.  Is it a good idea?  MyApp::Model::DB 
> appears to be part of the Catalyst application, so if I want to access the 
> database from an external model, it makes sense to me to move the 
> connection code outside of the Catalyst application.
>
>
> Regards,
>
> Mike


The best idea would be to put the connection information in the 
application's config file like in the example below. (This example uses a 
Perl data structure, but you can use any configuration type accepted by 
Config::Any).

'Model::DB' => {
  schema_class => 'MyApp::Schema',
  connect_info => {
    dsn => 'dbi:Oracle:host=10.10.10.10;port=1521;sid=ora8',
    user => 'user',
    password => "password",
    #name_sep => '.',
    LongReadLen => 100*1024*1024,
    LongTruncOk => 1,
    on_connect_call => 'datetime_setup',
    on_connect_do => [
      "alter session set NLS_COMP='LINGUISTIC'",
      "alter session set NLS_SORT='BINARY_AI'",
    ],
  },
},

The model will access the connection information directly if it is defined 
in the config file, and you can use the data from this config file in any 
other external program.
You can use the module Config::JFDI for using the Catalyst config file 
easier.

Octavian