use strict;
use warnings;
+use Scalar::Util qw/blessed/;
+
+use base qw/DBIx::Class::Row/;
+
+=head1 NAME
+
+DBIx::Class::InflateColumn - Automatically create objects from column data
+
+=head1 SYNOPSIS
+
+ # In your table classes
+ __PACKAGE__->inflate_column('column_name', {
+ inflate => sub { ... },
+ deflate => sub { ... },
+ });
+
+=head1 DESCRIPTION
+
+This component translates column data into objects, i.e. "inflating"
+the column data. It also "deflates" objects into an appropriate format
+for the database.
+
+It can be used, for example, to automatically convert to and from
+L<DateTime> objects for your date and time fields.
+
+=head1 METHODS
+
+=head2 inflate_column
+
+Instruct L<DBIx::Class> to inflate the given column.
+
+In addition to the column name, you must provide C<inflate> and
+C<deflate> methods. The C<inflate> method is called when you access
+the field, while the C<deflate> method is called when the field needs
+to used by the database.
+
+For example, if you have a table C<events> with a timestamp field
+named C<insert_time>, you could inflate the column in the
+corresponding table class using something like:
+
+ __PACKAGE__->inflate_column('insert_time', {
+ inflate => sub { DateTime::Format::Pg->parse_datetime(shift); },
+ deflate => sub { DateTime::Format::Pg->format_datetime(shift); },
+ });
+
+(Replace L<DateTime::Format::Pg> with the appropriate module for your
+database, or consider L<DateTime::Format::DBI>.)
+
+The coderefs you set for inflate and deflate are called with two parameters,
+the first is the value of the column to be inflated/deflated, the second is the
+row object itself. Thus you can call C<< ->result_source->schema->storage->dbh >> on
+it, to feed to L<DateTime::Format::DBI>.
+
+In this example, calls to an event's C<insert_time> accessor return a
+L<DateTime> object. This L<DateTime> object is later "deflated" when
+used in the database layer.
+
+=cut
sub inflate_column {
my ($self, $col, $attrs) = @_;
- die "No such column $col to inflate" unless $self->has_column($col);
- die "inflate_column needs attr hashref" unless ref $attrs eq 'HASH';
+ $self->throw_exception("No such column $col to inflate")
+ unless $self->has_column($col);
+ $self->throw_exception("inflate_column needs attr hashref")
+ unless ref $attrs eq 'HASH';
$self->column_info($col)->{_inflate_info} = $attrs;
$self->mk_group_accessors('inflated_column' => $col);
return 1;
sub _inflated_column {
my ($self, $col, $value) = @_;
return $value unless defined $value; # NULL is NULL is NULL
- my $info = $self->column_info($col) || die "No column info for $col";
+ my $info = $self->column_info($col)
+ or $self->throw_exception("No column info for $col");
return $value unless exists $info->{_inflate_info};
my $inflate = $info->{_inflate_info}{inflate};
- die "No inflator for $col" unless defined $inflate;
+ $self->throw_exception("No inflator for $col") unless defined $inflate;
return $inflate->($value, $self);
}
sub _deflated_column {
my ($self, $col, $value) = @_;
return $value unless ref $value; # If it's not an object, don't touch it
- my $info = $self->column_info($col) || die "No column info for $col";
+ my $info = $self->column_info($col) or
+ $self->throw_exception("No column info for $col");
return $value unless exists $info->{_inflate_info};
my $deflate = $info->{_inflate_info}{deflate};
- die "No deflator for $col" unless defined $deflate;
+ $self->throw_exception("No deflator for $col") unless defined $deflate;
return $deflate->($value, $self);
}
+=head2 get_inflated_column
+
+ my $val = $obj->get_inflated_column($col);
+
+Fetch a column value in its inflated state. This is directly
+analogous to L<DBIx::Class::Row/get_column> in that it only fetches a
+column already retreived from the database, and then inflates it.
+Throws an exception if the column requested is not an inflated column.
+
+=cut
+
sub get_inflated_column {
my ($self, $col) = @_;
- $self->throw("$col is not an inflated column") unless
- exists $self->column_info($col)->{_inflate_info};
-
+ $self->throw_exception("$col is not an inflated column")
+ unless exists $self->column_info($col)->{_inflate_info};
return $self->{_inflated_column}{$col}
if exists $self->{_inflated_column}{$col};
return $self->{_inflated_column}{$col} =
$self->_inflated_column($col, $self->get_column($col));
}
+=head2 set_inflated_column
+
+ my $copy = $obj->set_inflated_column($col => $val);
+
+Sets a column value from an inflated value. This is directly
+analogous to L<DBIx::Class::Row/set_column>.
+
+=cut
+
sub set_inflated_column {
- my ($self, $col, @rest) = @_;
- my $ret = $self->store_inflated_column($col, @rest);
- $self->{_dirty_columns}{$col} = 1;
- return $ret;
+ my ($self, $col, $obj) = @_;
+ $self->set_column($col, $self->_deflated_column($col, $obj));
+ if (blessed $obj) {
+ $self->{_inflated_column}{$col} = $obj;
+ } else {
+ delete $self->{_inflated_column}{$col};
+ }
+ return $obj;
}
+=head2 store_inflated_column
+
+ my $copy = $obj->store_inflated_column($col => $val);
+
+Sets a column value from an inflated value without marking the column
+as dirty. This is directly analogous to L<DBIx::Class::Row/store_column>.
+
+=cut
+
sub store_inflated_column {
my ($self, $col, $obj) = @_;
- unless (ref $obj) {
- delete $self->{_inflated_column}{$col};
- return $self->store_column($col, $obj);
+ unless (blessed $obj) {
+ delete $self->{_inflated_column}{$col};
+ $self->store_column($col => $obj);
+ return $obj;
}
+ delete $self->{_column_data}{$col};
+ return $self->{_inflated_column}{$col} = $obj;
+}
- my $deflated = $self->_deflated_column($col, $obj);
- # Do this now so we don't store if it's invalid
+=head2 get_column
- $self->{_inflated_column}{$col} = $obj;
- #warn "Storing $obj: ".($obj->_ident_values)[0];
- $self->store_column($col, $deflated);
- return $obj;
+Gets a column value in the same way as L<DBIx::Class::Row/get_column>. If there
+is an inflated value stored that has not yet been deflated, it is deflated
+when the method is invoked.
+
+=cut
+
+sub get_column {
+ my ($self, $col) = @_;
+ if (exists $self->{_inflated_column}{$col}
+ && !exists $self->{_column_data}{$col}) {
+ $self->store_column($col, $self->_deflated_column($col, $self->{_inflated_column}{$col}));
+ }
+ return $self->next::method($col);
}
-sub new {
+=head2 get_columns
+
+Returns the get_column info for all columns as a hash,
+just like L<DBIx::Class::Row/get_columns>. Handles inflation just
+like L</get_column>.
+
+=cut
+
+sub get_columns {
+ my $self = shift;
+ if (exists $self->{_inflated_column}) {
+ foreach my $col (keys %{$self->{_inflated_column}}) {
+ $self->store_column($col, $self->_deflated_column($col, $self->{_inflated_column}{$col}))
+ unless exists $self->{_column_data}{$col};
+ }
+ }
+ return $self->next::method;
+}
+
+=head2 has_column_loaded
+
+Like L<DBIx::Class::Row/has_column_loaded>, but also returns true if there
+is an inflated value stored.
+
+=cut
+
+sub has_column_loaded {
+ my ($self, $col) = @_;
+ return 1 if exists $self->{_inflated_column}{$col};
+ return $self->next::method($col);
+}
+
+=head2 update
+
+Updates a row in the same way as L<DBIx::Class::Row/update>, handling
+inflation and deflation of columns appropriately.
+
+=cut
+
+sub update {
my ($class, $attrs, @rest) = @_;
- $attrs ||= {};
- foreach my $key (keys %$attrs) {
- if (ref $attrs->{$key}
+ foreach my $key (keys %{$attrs||{}}) {
+ if (ref $attrs->{$key} && $class->has_column($key)
&& exists $class->column_info($key)->{_inflate_info}) {
- $attrs->{$key} = $class->_deflated_column($key, $attrs->{$key});
+ $class->set_inflated_column($key, delete $attrs->{$key});
}
}
- return $class->NEXT::ACTUAL::new($attrs, @rest);
+ return $class->next::method($attrs, @rest);
+}
+
+=head2 new
+
+Creates a row in the same way as L<DBIx::Class::Row/new>, handling
+inflation and deflation of columns appropriately.
+
+=cut
+
+sub new {
+ my ($class, $attrs, @rest) = @_;
+ my $inflated;
+ foreach my $key (keys %{$attrs||{}}) {
+ $inflated->{$key} = delete $attrs->{$key}
+ if ref $attrs->{$key} && $class->has_column($key)
+ && exists $class->column_info($key)->{_inflate_info};
+ }
+ my $obj = $class->next::method($attrs, @rest);
+ $obj->{_inflated_column} = $inflated if $inflated;
+ return $obj;
}
+=head1 SEE ALSO
+
+=over 4
+
+=item L<DBIx::Class::Core> - This component is loaded as part of the
+ "core" L<DBIx::Class> components; generally there is no need to
+ load it directly
+
+=back
+
+=head1 AUTHOR
+
+Matt S. Trout <mst@shadowcatsystems.co.uk>
+
+=head1 CONTRIBUTORS
+
+Daniel Westermann-Clark <danieltwc@cpan.org> (documentation)
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+
+=cut
+
1;
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