Catalyst::Model::DBIC::Schema.3pm

Langue: en

Version: 2010-02-04 (fedora - 01/12/10)

Section: 3 (Bibliothèques de fonctions)

NAME

Catalyst::Model::DBIC::Schema - DBIx::Class::Schema Model Class

SYNOPSIS

First, prepare your database schema using DBIx::Class, see Catalyst::Helper::Model::DBIC::Schema for how to generate a DBIx::Class::Schema from your database using the Helper script, and DBIx::Class::Schema::Loader::Base.

A typical usage of the helper script would be:

     script/myapp_create.pl model FilmDB DBIC::Schema MyApp::Schema::FilmDB \
         create=static dbi:mysql:filmdb dbusername dbpass \
         quote_char='`' name_sep='.'
 
 

If you are unfamiliar with DBIx::Class, see DBIx::Class::Manual::Intro first.

These examples assume that you already have a schema called "MyApp::Schema::FilmDB", which defines some Result classes for tables in "MyApp::Schema::FilmDB::Result::Actor" and "MyApp::Schema::FilmDB::Result::Film". Either created by the helper script (as shown above) or manually.

The helper also creates a Model in "lib/MyApp/Model/FilmDB.pm", if you already have a schema you can create just the Model using:

     script/myapp_create.pl model FilmDB DBIC::Schema MyApp::Schema::FilmDB
         dbi:mysql:filmdb dbusername dbpass
 
 

The connect_info is optional and will be hardcoded into the Model if provided. It's better to configure it in your Catalyst config file, which will also override any hardcoded config, see ``connect_info'' for examples.

Now you have a working Model which accesses your separate DBIC Schema. This can be used/accessed in the normal Catalyst manner, via "$c->model()":

   my $db_model = $c->model('FilmDB');         # a Catalyst::Model
   my $dbic     = $c->model('FilmDB')->schema; # the actual DBIC object
 
 

There is also a shortcut, which returns a DBIx::Class::ResultSet directly, instead of a Catalyst::Model:

   my $rs = $c->model('FilmDB::Actor');
 
 

See DBIx::Class::ResultSet to find out more about which methods can be called on ResultSets.

You can also define your own ResultSet methods to encapsulate the database/business logic of your applications. These go into, for example, "lib/MyApp/Schema/FilmDB/ResultSet/Actor.pm". The class must inherit from DBIx::Class::ResultSet and is automatically loaded.

Then call your methods like any other DBIx::Class::ResultSet method:

     $c->model('FilmDB::Actor')->SAG_members
 
 

Some examples:

   # to access schema methods directly:
   $c->model('FilmDB')->schema->source(...);
 
   # to access the source object, resultset, and class:
   $c->model('FilmDB')->source(...);
   $c->model('FilmDB')->resultset(...);
   $c->model('FilmDB')->class(...);
 
   # For resultsets, there's an even quicker shortcut:
   $c->model('FilmDB::Actor')
   # is the same as $c->model('FilmDB')->resultset('Actor')
 
   # To get the composed schema for making new connections:
   my $newconn = $c->model('FilmDB')->composed_schema->connect(...);
 
   # Or the same thing via a convenience shortcut:
   my $newconn = $c->model('FilmDB')->connect(...);
 
   # or, if your schema works on different storage drivers:
   my $newconn = $c->model('FilmDB')->composed_schema->clone();
   $newconn->storage_type('::LDAP');
   $newconn->connection(...);
 
   # and again, a convenience shortcut
   my $newconn = $c->model('FilmDB')->clone();
   $newconn->storage_type('::LDAP');
   $newconn->connection(...);
 
 

To set up authentication, see ``Setting up DBIC authentication'' below.

DESCRIPTION

This is a Catalyst Model for DBIx::Class::Schema-based Models. See the documentation for Catalyst::Helper::Model::DBIC::Schema for information on generating these Models via Helper scripts.

When your Catalyst app starts up, a thin Model layer is created as an interface to your DBIC Schema. It should be clearly noted that the model object returned by "$c->model('FilmDB')" is NOT itself a DBIC schema or resultset object, but merely a wrapper proving methods to access the underlying schema.

In addition to this model class, a shortcut class is generated for each source in the schema, allowing easy and direct access to a resultset of the corresponding type. These generated classes are even thinner than the model class, providing no public methods but simply hooking into Catalyst's model() accessor via the ACCEPT_CONTEXT mechanism. The complete contents of each generated class is roughly equivalent to the following:

   package MyApp::Model::FilmDB::Actor
   sub ACCEPT_CONTEXT {
       my ($self, $c) = @_;
       $c->model('FilmDB')->resultset('Actor');
   }
 
 

In short, there are three techniques available for obtaining a DBIC resultset object:

   # the long way
   my $rs = $c->model('FilmDB')->schema->resultset('Actor');
 
   # using the shortcut method on the model object
   my $rs = $c->model('FilmDB')->resultset('Actor');
 
   # using the generated class directly
   my $rs = $c->model('FilmDB::Actor');
 
 

In order to add methods to a DBIC resultset, you cannot simply add them to the source (row, table) definition class; you must define a separate custom resultset class. This is just a matter of making a "lib/MyApp/Schema/ResultSet/Actor.pm" class that inherits from DBIx::Class::ResultSet, if you are using ``load_namespaces'' in DBIx::Class::Schema, the default for helper script generated schemas.

See ``Predefined searches'' in DBIx::Class::Manual::Cookbook for information on definining your own DBIx::Class::ResultSet classes for use with ``load_classes'' in DBIx::Class::Schema, the old default.

CONFIG PARAMETERS

schema_class

This is the classname of your DBIx::Class::Schema Schema. It needs to be findable in @INC, but it does not need to be inside the "Catalyst::Model::" namespace. This parameter is required.

connect_info

This is an arrayref of connection parameters, which are specific to your "storage_type" (see your storage type documentation for more details). If you only need one parameter (e.g. the DSN), you can just pass a string instead of an arrayref.

This is not required if "schema_class" already has connection information defined inside itself (which isn't highly recommended, but can be done)

For DBIx::Class::Storage::DBI, which is the only supported "storage_type" in DBIx::Class at the time of this writing, the parameters are your dsn, username, password, and connect options hashref.

See ``connect_info'' in DBIx::Class::Storage::DBI for a detailed explanation of the arguments supported.

Examples:

   connect_info => {
     dsn => 'dbi:Pg:dbname=mypgdb',
     user => 'postgres',
     password => ''
   }
 
   connect_info => {
     dsn => 'dbi:SQLite:dbname=foo.db',
     on_connect_do => [
       'PRAGMA synchronous = OFF',
     ]
   }
 
   connect_info => {
     dsn => 'dbi:Pg:dbname=mypgdb',
     user => 'postgres',
     password => '',
     pg_enable_utf8 => 1,
     on_connect_do => [
       'some SQL statement',
       'another SQL statement',
     ],
   }
 
 

Or using Config::General:

     <Model::FilmDB>
         schema_class   MyApp::Schema::FilmDB
         traits Caching
         <connect_info>
             dsn   dbi:Pg:dbname=mypgdb
             user   postgres
             password ""
             auto_savepoint 1
             quote_char """
             on_connect_do   some SQL statement
             on_connect_do   another SQL statement
         </connect_info>
         user_defined_schema_accessor foo
     </Model::FilmDB>
 
 

or

     <Model::FilmDB>
         schema_class   MyApp::Schema::FilmDB
         connect_info   dbi:SQLite:dbname=foo.db
     </Model::FilmDB>
 
 

Or using YAML:

   Model::MyDB:
       schema_class: MyDB
       traits: Caching
       connect_info:
           dsn: dbi:Oracle:mydb
           user: mtfnpy
           password: mypass
           LongReadLen: 1000000
           LongTruncOk: 1
           on_connect_call: 'datetime_setup'
           quote_char: '"'
 
 

The old arrayref style with hashrefs for DBI then DBIx::Class options is also supported:

   connect_info => [
     'dbi:Pg:dbname=mypgdb',
     'postgres',
     '',
     {
       pg_enable_utf8 => 1,
     },
     {
       auto_savepoint => 1,
       on_connect_do => [
         'some SQL statement',
         'another SQL statement',
       ],
     }
   ]
 
 

traits

Array of Traits to apply to the instance. Traits are Moose::Roles.

They are relative to the "MyApp::TraitFor::Model::DBIC::Schema::", then the "Catalyst::TraitFor::Model::DBIC::Schema::" namespaces, unless prefixed with "+" in which case they are taken to be a fully qualified name. E.g.:

     traits Caching
     traits +MyApp::TraitFor::Model::Foo
 
 

A new instance is created at application time, so any consumed required attributes, coercions and modifiers will work.

Traits are applied at ``COMPONENT'' in Catalyst::Component time using CatalystX::Component::Traits.

"ref $self" will be an anon class if any traits are applied, "$self->_original_class_name" will be the original class.

When writing a Trait, interesting points to modify are "BUILD", ``setup'' and ``ACCEPT_CONTEXT''.

Traits that come with the distribution:

Catalyst::TraitFor::Model::DBIC::Schema::Caching
Catalyst::TraitFor::Model::DBIC::Schema::Replicated
Catalyst::TraitFor::Model::DBIC::Schema::SchemaProxy

storage_type

Allows the use of a different "storage_type" than what is set in your "schema_class" (which in turn defaults to "::DBI" if not set in current DBIx::Class). Completely optional, and probably unnecessary for most people until other storage backends become available for DBIx::Class.

ATTRIBUTES

The keys you pass in the model configuration are available as attributes.

Other attributes available:

connect_info

Your connect_info args normalized to hashref form (with dsn/user/password.) See ``connect_info'' in DBIx::Class::Storage::DBI for more info on the hashref form of ``connect_info''.

model_name

The model name Catalyst uses to resolve this model, the part after "::Model::" or "::M::" in your class name. E.g. if your class name is "MyApp::Model::DB" the ``model_name'' will be "DB".

_default_cursor_class

What to reset your ``cursor_class'' in DBIx::Class::Storage::DBI to if a custom one doesn't work out. Defaults to DBIx::Class::Storage::DBI::Cursor.

ATTRIBUTES FROM MooseX::Traits::Pluggable

_original_class_name

The class name of your model before any ``traits'' are applied. E.g. "MyApp::Model::DB".

_traits

Unresolved arrayref of traits passed in the config.

_resolved_traits

Traits you used resolved to full class names.

METHODS

new

Instantiates the Model based on the above-documented ->config parameters. The only required parameter is "schema_class". "connect_info" is required in the case that "schema_class" does not already have connection information defined for it.

schema

Accessor which returns the connected schema being used by the this model. There are direct shortcuts on the model class itself for schema->resultset, schema->source, and schema->class.

composed_schema

Accessor which returns the composed schema, which has no connection info, which was used in constructing the "schema" above. Useful for creating new connections based on the same schema/model. There are direct shortcuts from the model object for composed_schema->clone and composed_schema->connect

clone

Shortcut for ->composed_schema->clone

connect

Shortcut for ->composed_schema->connect

source

Shortcut for ->schema->source

class

Shortcut for ->schema->class

resultset

Shortcut for ->schema->resultset

txn_do

Shortcut for ->schema->txn_do

txn_scope_guard

Shortcut for ->schema->txn_scope_guard

storage

Provides an accessor for the connected schema's storage object. Used often for debugging and controlling transactions.

setup

Called at "BUILD" time before configuration, but after ``connect_info'' is set. To do something after configuuration use "after BUILD =>".

Receives a hashref of args passed to "BUILD".

ACCEPT_CONTEXT

Point of extension for doing things at "$c->model" time with context, returns the model instance, see ``ACCEPT_CONTEXT'' in Catalyst::Manual::Intro for more information.

ENVIRONMENT

CMDS_NO_SOURCES
Set this variable if you will be using schemas with no sources (Result classes) to disable the warning. The warning is there because having no Result classes is usually a mistake.

Setting up DBIC authentication

You can set this up with Catalyst::Authentication::Store::DBIx::Class in MyApp.pm:
   package MyApp;
 
   use Catalyst qw/... Authentication .../;
 
   ...
 
   __PACKAGE__->config('Plugin::Authentication' =>
                 {
                     default_realm => 'members',
                     members => {
                         credential => {
                             class => 'Password',
                             password_field => 'password',
                             password_type => 'hashed'
                             password_hash_type => 'SHA-256'
                         },
                         store => {
                             class => 'DBIx::Class',
                             user_model => 'DB::User',
                             role_relation => 'roles',
                             role_field => 'rolename',
                         }
                     }
                 });
 
 

METHOD PROXYING

The automatic proxying to the underlying DBIx::Class::Schema has been removed as of version 0.34, to enable this feature add "SchemaProxy" to ``traits''.

See Catalyst::TraitFor::Model::DBIC::Schema::SchemaProxy.

SEE ALSO

General Catalyst Stuff:

Catalyst::Manual, Catalyst::Test, Catalyst::Request, Catalyst::Response, Catalyst::Helper, Catalyst,

Stuff related to DBIC and this Model style:

DBIx::Class, DBIx::Class::Schema, DBIx::Class::Schema::Loader, Catalyst::Helper::Model::DBIC::Schema, CatalystX::Component::Traits, MooseX::Traits::Pluggable

Traits:

Catalyst::TraitFor::Model::DBIC::Schema::Caching, Catalyst::TraitFor::Model::DBIC::Schema::Replicated, Catalyst::TraitFor::Model::DBIC::Schema::SchemaProxy, Catalyst::TraitFor::Model::DBIC::Schema::QueryLog

AUTHOR

Brandon L Black "blblack at gmail.com"

CONTRIBUTORS

caelum: Rafael Kitover "rkitover at cpan.org"

dandv: Dan Dascalescu "dandv at cpan.org"

bluefeet: Aran Deltac "bluefeet@cpan.org"

t0m: Tomas Doran "bobtfish@bobtfish.net"

osfameron: "osfameron@cpan.org"

ozum: Ozum Eldogan "ozum@ozum.net"

Pavel I. Shaydo "zwon@trinitum.org"

Copyright (c) 2006 - 2009 the Catalyst::Model::DBIC::Schema ``AUTHOR'' and ``CONTRIBUTORS'' as listed above.

LICENSE

This program is free software. You can redistribute it and/or modify it under the same terms as Perl itself.