1 package DBIx::Class::InflateColumn;
6 use base 'DBIx::Class::Row';
7 use SQL::Abstract 'is_literal_value';
12 DBIx::Class::InflateColumn - Automatically create references from column data
16 # In your table classes
17 __PACKAGE__->inflate_column('column_name', {
19 my ($raw_value_from_db, $result_object) = @_;
23 my ($inflated_value_from_user, $result_object) = @_;
30 This component translates column data into references, i.e. "inflating"
31 the column data. It also "deflates" references into an appropriate format
34 It can be used, for example, to automatically convert to and from
35 L<DateTime> objects for your date and time fields. There's a
36 convenience component to actually do that though, try
37 L<DBIx::Class::InflateColumn::DateTime>.
39 It will handle all types of references except scalar references. It
40 will not handle scalar values, these are ignored and thus passed
41 through to L<SQL::Abstract>. This is to allow setting raw values to
42 "just work". Scalar references are passed through to the database to
43 deal with, to allow such settings as C< \'year + 1'> and C< \'DEFAULT' >
46 If you want to filter plain scalar values and replace them with
47 something else, see L<DBIx::Class::FilterColumn>.
53 Instruct L<DBIx::Class> to inflate the given column.
55 In addition to the column name, you must provide C<inflate> and
56 C<deflate> methods. The C<inflate> method is called when you access
57 the field, while the C<deflate> method is called when the field needs
58 to used by the database.
60 For example, if you have a table C<events> with a timestamp field
61 named C<insert_time>, you could inflate the column in the
62 corresponding table class using something like:
64 __PACKAGE__->inflate_column('insert_time', {
66 my ($insert_time_raw_value, $event_result_object) = @_;
67 DateTime->from_epoch( epoch => $insert_time_raw_value );
70 my ($insert_time_dt_object, $event_result_object) = @_;
71 $insert_time_dt_object->epoch;
75 The coderefs you set for inflate and deflate are called with two parameters,
76 the first is the value of the column to be inflated/deflated, the second is
77 the result object itself.
79 In this example, calls to an event's C<insert_time> accessor return a
80 L<DateTime> object. This L<DateTime> object is later "deflated" back
81 to the integer epoch representation when used in the database layer.
82 For a much more thorough handling of the above example, please see
83 L<DBIx::Class::DateTime::Epoch>
88 my ($self, $col, $attrs) = @_;
90 my $colinfo = $self->result_source->columns_info([$col])->{$col};
92 $self->throw_exception("InflateColumn can not be used on a column with a declared FilterColumn filter")
93 if defined $colinfo->{_filter_info} and $self->isa('DBIx::Class::FilterColumn');
95 $self->throw_exception("inflate_column needs attr hashref")
96 unless ref $attrs eq 'HASH';
98 $colinfo->{_inflate_info} = $attrs;
99 my $acc = $colinfo->{accessor};
100 $self->mk_group_accessors('inflated_column' => [ (defined $acc ? $acc : $col), $col]);
104 sub _inflated_column {
105 my ($self, $col, $value) = @_;
108 ! defined $value # NULL is NULL is NULL
110 is_literal_value($value) #that would be a not-yet-reloaded literal update
113 my $info = $self->result_source->columns_info([$col])->{$col};
115 return $value unless exists $info->{_inflate_info};
118 $info->{_inflate_info}{inflate}
120 $self->throw_exception("No inflator found for '$col'")
124 sub _deflated_column {
125 my ($self, $col, $value) = @_;
127 ## Deflate any refs except for literals, pass through plain values
131 is_literal_value($value)
134 my $info = $self->result_source->columns_info([$col])->{$col};
136 return $value unless exists $info->{_inflate_info};
139 $info->{_inflate_info}{deflate}
141 $self->throw_exception("No deflator found for '$col'")
145 =head2 get_inflated_column
147 my $val = $obj->get_inflated_column($col);
149 Fetch a column value in its inflated state. This is directly
150 analogous to L<DBIx::Class::Row/get_column> in that it only fetches a
151 column already retrieved from the database, and then inflates it.
152 Throws an exception if the column requested is not an inflated column.
156 sub get_inflated_column {
157 my ($self, $col) = @_;
159 $self->throw_exception("$col is not an inflated column")
160 unless exists $self->result_source->columns_info->{$col}{_inflate_info};
162 # we take care of keeping things in sync
163 return $self->{_inflated_column}{$col}
164 if exists $self->{_inflated_column}{$col};
166 my $val = $self->get_column($col);
168 return $self->{_inflated_column}{$col} = $self->_inflated_column($col, $val);
171 =head2 set_inflated_column
173 my $copy = $obj->set_inflated_column($col => $val);
175 Sets a column value from an inflated value. This is directly
176 analogous to L<DBIx::Class::Row/set_column>.
180 sub set_inflated_column {
181 my ($self, $col, $value) = @_;
183 # pass through deflated stuff
184 if (! length ref $value or is_literal_value($value)) {
185 $self->set_column($col, $value);
186 delete $self->{_inflated_column}{$col};
188 # need to call set_column with the deflate cycle so that
189 # relationship caches are nuked if any
190 # also does the compare-for-dirtyness and change tracking dance
192 $self->set_column($col, $self->_deflated_column($col, $value));
193 $self->{_inflated_column}{$col} = $value;
199 =head2 store_inflated_column
201 my $copy = $obj->store_inflated_column($col => $val);
203 Sets a column value from an inflated value without marking the column
204 as dirty. This is directly analogous to L<DBIx::Class::Row/store_column>.
208 sub store_inflated_column {
209 my ($self, $col, $value) = @_;
211 if (! length ref $value or is_literal_value($value)) {
212 delete $self->{_inflated_column}{$col};
213 $self->store_column($col => $value);
216 delete $self->{_column_data}{$col};
217 $self->{_inflated_column}{$col} = $value;
227 =item L<DBIx::Class::Core> - This component is loaded as part of the
228 C<core> L<DBIx::Class> components; generally there is no need to
233 =head1 FURTHER QUESTIONS?
235 Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.
237 =head1 COPYRIGHT AND LICENSE
239 This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE>
240 by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can
241 redistribute it and/or modify it under the same terms as the
242 L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>.