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lib/Alzabo/Create/Schema.pm  view on Meta::CPAN

package Alzabo::Create::Schema;

use strict;
use vars qw($VERSION);

use Alzabo::ChangeTracker;
use Alzabo::Config;
use Alzabo::Create;
use Alzabo::Driver;
use Alzabo::Exceptions
    ( abbr => [ qw( params_exception system_exception ) ] );
use Alzabo::RDBMSRules;
use Alzabo::Runtime;
use Alzabo::SQLMaker;
use Alzabo::Utils;

use File::Spec;

use Params::Validate qw( :all );
Params::Validate::validation_options
    ( on_fail => sub { params_exception join '', @_ } );

use Storable ();
use Tie::IxHash;

use base qw( Alzabo::Schema );

$VERSION = 2.0;

1;

sub new
{
    my $proto = shift;
    my $class = ref $proto || $proto;

    validate( @_, { rdbms    => { type => SCALAR },
                    name     => { type => SCALAR },
                    no_cache => { type => SCALAR, default => 0 },
                  } );
    my %p = @_;

    my $self = bless {}, $class;

    params_exception "Alzabo does not support the '$p{rdbms}' RDBMS"
        unless ( ( grep { $p{rdbms} eq $_ } Alzabo::Driver->available ) &&
                 ( grep { $p{rdbms} eq $_ } Alzabo::RDBMSRules->available ) );

    $self->{driver} = Alzabo::Driver->new( rdbms => $p{rdbms},
                                           schema => $self );
    $self->{rules} = Alzabo::RDBMSRules->new( rdbms => $p{rdbms} );

    $self->{sql} = Alzabo::SQLMaker->load( rdbms => $p{rdbms} );

    params_exception "Alzabo::Create::Schema->new requires a name parameter\n"
        unless exists $p{name};

    $self->set_name($p{name});

    $self->{tables} = Tie::IxHash->new;

    $self->_save_to_cache unless $p{no_cache};

    return $self;
}

sub load_from_file
{
    return shift->_load_from_file(@_);
}

sub reverse_engineer
{
    my $proto = shift;
    my $class = ref $proto || $proto;
    my %p = @_;

    my $self = $class->new( name     => $p{name},
                            rdbms    => $p{rdbms},
                            no_cache => 1,
                          );

    delete $p{rdbms};
    $self->{driver}->connect(%p);

    $self->{rules}->reverse_engineer($self);

    $self->set_instantiated(1);
    my $driver = delete $self->{driver};
    $self->{original} = Storable::dclone($self);
    $self->{driver} = $driver;
    delete $self->{original}{original};
    return $self;
}

sub set_name
{
    my $self = shift;

    validate_pos( @_, { type => SCALAR } );
    my $name = shift;

    return if defined $self->{name} && $name eq $self->{name};

lib/Alzabo/Create/Schema.pm  view on Meta::CPAN

        or system_exception "Can't write to $version_save_name: $!";
    close $fh
        or system_exception "Unable to close $version_save_name: $!";

    my $rt = $self->runtime_clone;

    my $runtime_save_name = $self->_base_filename( $self->{name} ) . '.runtime.alz';

    open $fh, ">$runtime_save_name"
        or system_exception "Unable to write to $runtime_save_name: $!\n";
    Storable::nstore_fd( $rt, $fh )
        or system_exception "Can't store to filehandle";
    close $fh
        or system_exception "Unable to close $runtime_save_name: $!";

    $self->_save_to_cache;
}

sub clone
{
    my $self = shift;

    validate( @_, { name  => { type => SCALAR } } );
    my %p = @_;

    my $driver = delete $self->{driver};
    my $clone = Storable::dclone($self);
    $self->{driver} = $driver;

    $clone->{name} = $p{name};
    $clone->{driver} = Alzabo::Driver->new( rdbms => $self->{driver}->driver_id,
                                            schema => $clone );

    $clone->rules->validate_schema_name($clone);
    $clone->{original}{name} = $p{name} if $p{name};

    $clone->set_instantiated(0);

    return $clone;
}

sub runtime_clone
{
    my $self = shift;

    my %s;
    my $driver = delete $self->{driver};
    my $clone = Storable::dclone($self);
    $self->{driver} = $driver;

    foreach my $f ( qw( original instantiated rules driver ) )
    {
        delete $clone->{$f};
    }

    foreach my $t ($clone->tables)
    {
        foreach my $c ($t->columns)
        {
            my $def = $c->definition;
            bless $def, 'Alzabo::Runtime::ColumnDefinition';
            bless $c, 'Alzabo::Runtime::Column';

            delete $c->{last_instantiation_name};
        }

        foreach my $fk ($t->all_foreign_keys)
        {
            bless $fk, 'Alzabo::Runtime::ForeignKey';
        }

        foreach my $i ($t->indexes)
        {
            bless $i, 'Alzabo::Runtime::Index';
        }

        delete $t->{last_instantiation_name};

        bless $t, 'Alzabo::Runtime::Table';
    }
    bless $clone, 'Alzabo::Runtime::Schema';

    return $clone;
}

sub save_current_name
{
    my $self = shift;

    $self->{last_instantiated_name} = $self->name;

    foreach my $table ( $self->tables )
    {
        $table->save_current_name;
    }
}

sub former_name { $_[0]->{last_instantiated_name} }

# Overrides method in base to load create schema instead of runtime
# schema
sub _schema_file_type
{
    return 'create';
}

__END__

=head1 NAME

Alzabo::Create::Schema - Schema objects for schema creation

=head1 SYNOPSIS

  use Alzabo::Create::Schema;

=head1 DESCRIPTION

This class represents the whole schema.  It contains table objects,
which in turn contain columns, indexes, etc.  It contains methods that
act globally on the schema, including methods to save it to disk,
create itself in an RDBMS, create relationships between tables, etc.

=head2 Instantiation

Every schema keeps track of whether it has been instantiated or not.
A schema that is instantiated is one that exists in an RDBMS backend.
This can be done explicitly by calling the schema's
L<C<create()>|Alzabo::Create::Schema/create> method.  It is also
implicitly set when a schema is created as the result of L<reverse
engineering|Alzabo::Create::Schema/reverse_engineer>.

The most important effect of instantiation is that once a schema is
instantiated, the way it generates SQL for itself changes.  Before it
is instantiated, if you ask it to generate SQL via L<the C<make_sql()>
the method|Alzabo::Create::Schema/make_sql>, it will generate the set
of SQL statements that are needed to create the schema from scratch.

After it is instantiated, the schema will instead generate the SQL
necessary to convert the version in the RDBMS backend to match the
object's current state.  This can be thought of as a SQL 'diff'.