Data::Mapper

My presentation about Data::Mapper at Kyoto.pm #1 on 2012-03-17. Data::Mapper is a simple ORM and a implementation of Data Mapper Pattern described in PofEAA.

Data::Mapper is available at https://github.com/kentaro/data-mapper

Transcript

1. Data::Mapper Kyoto.pm #1 2012-03-17 id:antipop / @kentaro
2. id:antipop @kentaro Programmer Ikemen Perler/Emacser/Hatena Kentaro Kuribayashi One of Representatives in Japanese IT industry
5. What’s Data::Mapper?
6. Sort of an ORM Simple & Clean
7. Why Yet Another ORM?
8. Using DBI Directly Full Stack ORM The Middle Way
9. API Design Simple Convention Performance Model for Every Data
10. An implementation of Data Mapper Pattern
11. Maps Data Between DB and In-memory Data Isolating Them from Each Other http://martinfowler.com/eaaCatalog/dataMapper.html
12. An object that wraps a row in a database table or view, encapsulates the database access, and adds domain logic on that data. http://martinfowler.com/eaaCatalog/activeRecord.html
13. Characters
14. Adapter Mapper Data
15. Mapper User Blog Entry User Blog Entry Adapter Data
16. Mapper User Blog Entry User Blog Entry Adapter Data
17. Adapter Database External API Memcached etc.
18. Data Data::Mapper::Data POPO (Plain Old Perl Object)
19. Mapper HashRef to HashRef Maps by Schema
20. Data::Mapper Convention
21. Create Find Search Update Delete Basic CRUD
22. Adapter Retrieves Data from Somewhere and Returns It as a HashRef Data Hash-based Object Knows Schema Info
23. Table <-> Data user <-> User user_info <-> UserInfo Table <-> Data Class user <-> D::M::Data::User user_info <-> D::M::Data::UserInfo (Customizable by D::M#data_class()
24. Usage
25. my $handler = DBIx::Handler->new(...); my $adapter = Data::Mapper::Adapter::DBI->new({ driver => sub { $handler->dbh } }); my $mapper = My::Mapper->new({ adapter => $adapter }); Instanciate
26. Mapper Adapter DBI API etc. adapter() driver()
27. my $data = $mapper->create(user => { name => 'kentaro', age => 34 }); #=> $data is a Data::Mapper::Data- based object Create
28. $data = $mapper->find(user => { name => 'kentaro' }); #=> $data is a Data::Mapper::Data- based object Retrieve
29. $result = $mapper->search(user => { age => 34 }, { order_by => 'id DESC' }); #=> $result is an ArrayRef of Data::Mapper::Data-based object Search
30. # Updates params like below $data->param(age => 35); my $sth = $mapper->update($data); $sth->rows; #=> 1 Update
31. my $sth = $mapper->delete($data); $sth->rows; #=> 1 Delete
32. # Data to Table sub mapped_params { my ($self, $data) = @_; my $table = $self- >to_table_name($data); my $schema = $self->adapter->schemata- >{$table} or Carp::croak("no such table: $table"); # snip } Schema
33. Advanced Usage
34. sub create { my ($self, $name, $args) = @_; my $content_type = File::MimeInfo::Magic::mimetype($args->{filename}); # $self->driver is a Fule::S3 object my $res = $self->driver->create_object_from_file( $name, $args->{key}, $args->{filename}, { content_type => $content_type, 'x-amz-acl' => $args->{acl}, } ); +{ bucket => $name, key => $args->{key}, type => $content_type, } } Adapter for External API
35. # How can we implement below? $user->blog; $blog->entries; Relation (Under Considering)
36. # Mapper sub map_data { # snip ... my $obj = $data_class->new($data); $obj->SOMESPECIALMETHOD($self) if $obj->isa('Data::Mapper::Data'); $obj; } # Data sub SOMESPECIALMETHOD { my ($self, $mapper) = @_; $self->{author} = $mapper->find(author => { id => $self->param('author_id') }); } Relation (Idea 1)
37. # Data sub mapper { my ($self, $mapper) = @_; $self->{_mapper} = $mapper if defined $mapper; $self->{_mapper}; } # Mapper sub map_data { my $self = shift; my $data = $self->SUPER::map_data(@_); $data->mapper($self); $data; } Relation (Idea 2)
38. # Data sub mapper { my ($self, $mapper) = @_; $self->{_mapper} = $mapper if defined $mapper; $self->{_mapper}; } # Mapper sub map_data { my $self = shift; my $data = $self->SUPER::map_data(@_); $data->mapper($self); $data; } Relation (Idea 2)
39. TODO: Relation (But Should It Be Supported by Module?) Master/Slave Unit of Work
40. Available on GitHub https://github.com/kentaro/data-mapper
41. Data::Mapper: Recap • Is a Simple ORM • Just Defines Minimum Conventions • Deals with Any Data from Anywhere
42. Any Questions?