1 package DBIx::Class::InflateColumn;
5 use Scalar::Util qw/blessed/;
7 use base qw/DBIx::Class::Row/;
11 DBIx::Class::InflateColumn - Automatically create references from column data
15 # In your table classes
16 __PACKAGE__->inflate_column('column_name', {
17 inflate => sub { ... },
18 deflate => sub { ... },
23 This component translates column data into references, i.e. "inflating"
24 the column data. It also "deflates" references into an appropriate format
27 It can be used, for example, to automatically convert to and from
28 L<DateTime> objects for your date and time fields.
30 It will accept arrayrefs, hashrefs and blessed references (objects),
31 but not scalarrefs. Scalar references are passed through to the
32 database to deal with, to allow such settings as C< \'year + 1'> and
33 C< \'DEFAULT' > to work.
39 Instruct L<DBIx::Class> to inflate the given column.
41 In addition to the column name, you must provide C<inflate> and
42 C<deflate> methods. The C<inflate> method is called when you access
43 the field, while the C<deflate> method is called when the field needs
44 to used by the database.
46 For example, if you have a table C<events> with a timestamp field
47 named C<insert_time>, you could inflate the column in the
48 corresponding table class using something like:
50 __PACKAGE__->inflate_column('insert_time', {
51 inflate => sub { DateTime::Format::Pg->parse_datetime(shift); },
52 deflate => sub { DateTime::Format::Pg->format_datetime(shift); },
55 (Replace L<DateTime::Format::Pg> with the appropriate module for your
56 database, or consider L<DateTime::Format::DBI>.)
58 The coderefs you set for inflate and deflate are called with two parameters,
59 the first is the value of the column to be inflated/deflated, the second is the
60 row object itself. Thus you can call C<< ->result_source->schema->storage->dbh >> on
61 it, to feed to L<DateTime::Format::DBI>.
63 In this example, calls to an event's C<insert_time> accessor return a
64 L<DateTime> object. This L<DateTime> object is later "deflated" when
65 used in the database layer.
70 my ($self, $col, $attrs) = @_;
71 $self->throw_exception("No such column $col to inflate")
72 unless $self->has_column($col);
73 $self->throw_exception("inflate_column needs attr hashref")
74 unless ref $attrs eq 'HASH';
75 $self->column_info($col)->{_inflate_info} = $attrs;
76 $self->mk_group_accessors('inflated_column' => [$self->column_info($col)->{accessor} || $col, $col]);
80 sub _inflated_column {
81 my ($self, $col, $value) = @_;
82 return $value unless defined $value; # NULL is NULL is NULL
83 my $info = $self->column_info($col)
84 or $self->throw_exception("No column info for $col");
85 return $value unless exists $info->{_inflate_info};
86 my $inflate = $info->{_inflate_info}{inflate};
87 $self->throw_exception("No inflator for $col") unless defined $inflate;
88 return $inflate->($value, $self);
91 sub _deflated_column {
92 my ($self, $col, $value) = @_;
93 # return $value unless ref $value && blessed($value); # If it's not an object, don't touch it
94 ## Leave scalar refs (ala SQL::Abstract literal SQL), untouched, deflate all other refs
95 return $value unless (ref $value && ref($value) ne 'SCALAR');
96 my $info = $self->column_info($col) or
97 $self->throw_exception("No column info for $col");
98 return $value unless exists $info->{_inflate_info};
99 my $deflate = $info->{_inflate_info}{deflate};
100 $self->throw_exception("No deflator for $col") unless defined $deflate;
101 return $deflate->($value, $self);
104 =head2 get_inflated_column
106 my $val = $obj->get_inflated_column($col);
108 Fetch a column value in its inflated state. This is directly
109 analogous to L<DBIx::Class::Row/get_column> in that it only fetches a
110 column already retreived from the database, and then inflates it.
111 Throws an exception if the column requested is not an inflated column.
115 sub get_inflated_column {
116 my ($self, $col) = @_;
117 $self->throw_exception("$col is not an inflated column")
118 unless exists $self->column_info($col)->{_inflate_info};
119 return $self->{_inflated_column}{$col}
120 if exists $self->{_inflated_column}{$col};
121 return $self->{_inflated_column}{$col} =
122 $self->_inflated_column($col, $self->get_column($col));
125 =head2 set_inflated_column
127 my $copy = $obj->set_inflated_column($col => $val);
129 Sets a column value from an inflated value. This is directly
130 analogous to L<DBIx::Class::Row/set_column>.
134 sub set_inflated_column {
135 my ($self, $col, $inflated) = @_;
136 $self->set_column($col, $self->_deflated_column($col, $inflated));
137 # if (blessed $inflated) {
138 if (ref $inflated && ref($inflated) ne 'SCALAR') {
139 $self->{_inflated_column}{$col} = $inflated;
141 delete $self->{_inflated_column}{$col};
146 =head2 store_inflated_column
148 my $copy = $obj->store_inflated_column($col => $val);
150 Sets a column value from an inflated value without marking the column
151 as dirty. This is directly analogous to L<DBIx::Class::Row/store_column>.
155 sub store_inflated_column {
156 my ($self, $col, $inflated) = @_;
157 # unless (blessed $inflated) {
158 unless (ref $inflated && ref($inflated) ne 'SCALAR') {
159 delete $self->{_inflated_column}{$col};
160 $self->store_column($col => $inflated);
163 delete $self->{_column_data}{$col};
164 return $self->{_inflated_column}{$col} = $inflated;
171 =item L<DBIx::Class::Core> - This component is loaded as part of the
172 "core" L<DBIx::Class> components; generally there is no need to
179 Matt S. Trout <mst@shadowcatsystems.co.uk>
183 Daniel Westermann-Clark <danieltwc@cpan.org> (documentation)
185 Jess Robinson <cpan@desert-island.demon.co.uk>
189 You may distribute this code under the same terms as Perl itself.