Data::Mapper - Speaker Deck

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Data::Mapper Kyoto.pm #1 2012-03-17 id:antipop / @kentaro

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id:antipop @kentaro Programmer Ikemen Perler/Emacser/Hatena Kentaro Kuribayashi One of Representatives in Japanese IT industry

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What’s Data::Mapper?

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Sort of an ORM Simple & Clean

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Why Yet Another ORM?

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Using DBI Directly Full Stack ORM The Middle Way

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API Design Simple Convention Performance Model for Every Data

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An implementation of Data Mapper Pattern

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Maps Data Between DB and In-memory Data Isolating Them from Each Other http://martinfowler.com/eaaCatalog/dataMapper.html

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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

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Characters

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Adapter Mapper Data

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Mapper User Blog Entry User Blog Entry Adapter Data

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Mapper User Blog Entry User Blog Entry Adapter Data

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Adapter Database External API Memcached etc.

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Data Data::Mapper::Data POPO (Plain Old Perl Object)

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Mapper HashRef to HashRef Maps by Schema

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Data::Mapper Convention

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Create Find Search Update Delete Basic CRUD

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Adapter Retrieves Data from Somewhere and Returns It as a HashRef Data Hash-based Object Knows Schema Info

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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()

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Usage

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my $handler = DBIx::Handler->new(...); my $adapter = Data::Mapper::Adapter::DBI->new({ driver => sub { $handler->dbh } }); my $mapper = My::Mapper->new({ adapter => $adapter }); Instanciate

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Mapper Adapter DBI API etc. adapter() driver()

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my $data = $mapper->create(user => { name => 'kentaro', age => 34 }); #=> $data is a Data::Mapper::Data- based object Create

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$data = $mapper->find(user => { name => 'kentaro' }); #=> $data is a Data::Mapper::Data- based object Retrieve

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$result = $mapper->search(user => { age => 34 }, { order_by => 'id DESC' }); #=> $result is an ArrayRef of Data::Mapper::Data-based object Search

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# Updates params like below $data->param(age => 35); my $sth = $mapper->update($data); $sth->rows; #=> 1 Update

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my $sth = $mapper->delete($data); $sth->rows; #=> 1 Delete

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# 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

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Advanced Usage

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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

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# How can we implement below? $user->blog; $blog->entries; Relation (Under Considering)

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# 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)

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# 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)

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TODO: Relation (But Should It Be Supported by Module?) Master/Slave Unit of Work

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Available on GitHub https://github.com/kentaro/data-mapper

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Data::Mapper: Recap • Is a Simple ORM • Just Defines Minimum Conventions • Deals with Any Data from Anywhere

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Any Questions?