use strict;
use warnings;
-use base qw/DBIx::Class::Row/;
+
+use base 'DBIx::Class::Row';
+use SQL::Abstract 'is_literal_value';
+use namespace::clean;
+
+=head1 NAME
+
+DBIx::Class::InflateColumn - Automatically create references from column data
+
+=head1 SYNOPSIS
+
+ # In your table classes
+ __PACKAGE__->inflate_column('column_name', {
+ inflate => sub {
+ my ($raw_value_from_db, $result_object) = @_;
+ ...
+ },
+ deflate => sub {
+ my ($inflated_value_from_user, $result_object) = @_;
+ ...
+ },
+ });
+
+=head1 DESCRIPTION
+
+This component translates column data into references, i.e. "inflating"
+the column data. It also "deflates" references into an appropriate format
+for the database.
+
+It can be used, for example, to automatically convert to and from
+L<DateTime> objects for your date and time fields. There's a
+convenience component to actually do that though, try
+L<DBIx::Class::InflateColumn::DateTime>.
+
+It will handle all types of references except scalar references. It
+will not handle scalar values, these are ignored and thus passed
+through to L<SQL::Abstract>. This is to allow setting raw values to
+"just work". Scalar references are passed through to the database to
+deal with, to allow such settings as C< \'year + 1'> and C< \'DEFAULT' >
+to work.
+
+If you want to filter plain scalar values and replace them with
+something else, see L<DBIx::Class::FilterColumn>.
+
+=head1 METHODS
+
+=head2 inflate_column
+
+Instruct L<DBIx::Class> to inflate the given column.
+
+In addition to the column name, you must provide C<inflate> and
+C<deflate> methods. The C<inflate> method is called when you access
+the field, while the C<deflate> method is called when the field needs
+to used by the database.
+
+For example, if you have a table C<events> with a timestamp field
+named C<insert_time>, you could inflate the column in the
+corresponding table class using something like:
+
+ __PACKAGE__->inflate_column('insert_time', {
+ inflate => sub {
+ my ($insert_time_raw_value, $event_result_object) = @_;
+ DateTime->from_epoch( epoch => $insert_time_raw_value );
+ },
+ deflate => sub {
+ my ($insert_time_dt_object, $event_result_object) = @_;
+ $insert_time_dt_object->epoch;
+ },
+ });
+
+The coderefs you set for inflate and deflate are called with two parameters,
+the first is the value of the column to be inflated/deflated, the second is
+the result object itself.
+
+In this example, calls to an event's C<insert_time> accessor return a
+L<DateTime> object. This L<DateTime> object is later "deflated" back
+to the integer epoch representation when used in the database layer.
+For a much more thorough handling of the above example, please see
+L<DBIx::Class::DateTime::Epoch>
+
+=cut
sub inflate_column {
my ($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';
- $self->column_info($col)->{_inflate_info} = $attrs;
- $self->mk_group_accessors('inflated_column' => $col);
+
+ my $colinfo = $self->column_info($col);
+
+ $self->throw_exception("InflateColumn can not be used on a column with a declared FilterColumn filter")
+ if defined $colinfo->{_filter_info} and $self->isa('DBIx::Class::FilterColumn');
+
+ $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';
+ $colinfo->{_inflate_info} = $attrs;
+ my $acc = $colinfo->{accessor};
+ $self->mk_group_accessors('inflated_column' => [ (defined $acc ? $acc : $col), $col]);
return 1;
}
sub _inflated_column {
my ($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";
+
+ return $value if (
+ ! defined $value # NULL is NULL is NULL
+ or
+ is_literal_value($value) #that would be a not-yet-reloaded literal update
+ );
+
+ my $info = $self->result_source->column_info($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;
- return $inflate->($value, $self);
+
+ return (
+ $info->{_inflate_info}{inflate}
+ ||
+ $self->throw_exception("No inflator found for '$col'")
+ )->($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";
+
+ ## Deflate any refs except for literals, pass through plain values
+ return $value if (
+ ! length ref $value
+ or
+ is_literal_value($value)
+ );
+
+ my $info = $self->result_source->column_info($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;
- return $deflate->($value, $self);
+
+ return (
+ $info->{_inflate_info}{deflate}
+ ||
+ $self->throw_exception("No deflator found for '$col'")
+ )->($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 retrieved 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 $self->result_source->column_info($col)->{_inflate_info};
+
+ # we take care of keeping things in sync
return $self->{_inflated_column}{$col}
if exists $self->{_inflated_column}{$col};
- return $self->{_inflated_column}{$col} =
- $self->_inflated_column($col, $self->get_column($col));
+
+ my $val = $self->get_column($col);
+
+ return $self->{_inflated_column}{$col} = $self->_inflated_column($col, $val);
}
+=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, $value) = @_;
-sub store_inflated_column {
- my ($self, $col, $obj) = @_;
- unless (ref $obj) {
+ # pass through deflated stuff
+ if (! length ref $value or is_literal_value($value)) {
+ $self->set_column($col, $value);
delete $self->{_inflated_column}{$col};
- return $self->store_column($col, $obj);
+ }
+ # need to call set_column with the deflate cycle so that
+ # relationship caches are nuked if any
+ # also does the compare-for-dirtyness and change tracking dance
+ else {
+ $self->set_column($col, $self->_deflated_column($col, $value));
+ $self->{_inflated_column}{$col} = $value;
}
- my $deflated = $self->_deflated_column($col, $obj);
- # Do this now so we don't store if it's invalid
-
- $self->{_inflated_column}{$col} = $obj;
- #warn "Storing $obj: ".($obj->_ident_values)[0];
- $self->store_column($col, $deflated);
- return $obj;
+ return $value;
}
-sub new {
- my ($class, $attrs, @rest) = @_;
- $attrs ||= {};
- foreach my $key (keys %$attrs) {
- if (ref $attrs->{$key}
- && exists $class->column_info($key)->{_inflate_info}) {
- $attrs->{$key} = $class->_deflated_column($key, $attrs->{$key});
- }
+=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, $value) = @_;
+
+ if (! length ref $value or is_literal_value($value)) {
+ delete $self->{_inflated_column}{$col};
+ $self->store_column($col => $value);
}
- return $class->next::method($attrs, @rest);
+ else {
+ delete $self->{_column_data}{$col};
+ $self->{_inflated_column}{$col} = $value;
+ }
+
+ return $value;
}
+=head1 SEE ALSO
+
+=over 4
+
+=item L<DBIx::Class::Core> - This component is loaded as part of the
+ C<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)
+
+Jess Robinson <cpan@desert-island.demon.co.uk>
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+
+=cut
+
1;