Commit | Line | Data |
0e5c2582 |
1 | package DBIx::Class::InflateColumn; |
2 | |
3 | use strict; |
4 | use warnings; |
aa562407 |
5 | |
aa562407 |
6 | |
75a23b3e |
7 | use base qw/DBIx::Class::Row/; |
0e5c2582 |
8 | |
75d07914 |
9 | =head1 NAME |
bcae85db |
10 | |
11 | DBIx::Class::InflateColumn - Automatically create objects from column data |
12 | |
13 | =head1 SYNOPSIS |
14 | |
15 | # In your table classes |
16 | __PACKAGE__->inflate_column('column_name', { |
17 | inflate => sub { ... }, |
18 | deflate => sub { ... }, |
19 | }); |
20 | |
21 | =head1 DESCRIPTION |
22 | |
23 | This component translates column data into objects, i.e. "inflating" |
24 | the column data. It also "deflates" objects into an appropriate format |
25 | for the database. |
26 | |
27 | It can be used, for example, to automatically convert to and from |
75d07914 |
28 | L<DateTime> objects for your date and time fields. |
bcae85db |
29 | |
30 | =head1 METHODS |
31 | |
32 | =head2 inflate_column |
33 | |
75d07914 |
34 | Instruct L<DBIx::Class> to inflate the given column. |
bcae85db |
35 | |
36 | In addition to the column name, you must provide C<inflate> and |
37 | C<deflate> methods. The C<inflate> method is called when you access |
38 | the field, while the C<deflate> method is called when the field needs |
39 | to used by the database. |
40 | |
41 | For example, if you have a table C<events> with a timestamp field |
42 | named C<insert_time>, you could inflate the column in the |
43 | corresponding table class using something like: |
44 | |
45 | __PACKAGE__->inflate_column('insert_time', { |
46 | inflate => sub { DateTime::Format::Pg->parse_datetime(shift); }, |
47 | deflate => sub { DateTime::Format::Pg->format_datetime(shift); }, |
48 | }); |
49 | |
50 | (Replace L<DateTime::Format::Pg> with the appropriate module for your |
51 | database, or consider L<DateTime::Format::DBI>.) |
52 | |
06fc5fc9 |
53 | The coderefs you set for inflate and deflate are called with two parameters, |
54 | the first is the value of the column to be inflated/deflated, the second is the |
55 | row object itself. Thus you can call C<< ->result_source->schema->storage->dbh >> on |
56 | it, to feed to L<DateTime::Format::DBI>. |
57 | |
bcae85db |
58 | In this example, calls to an event's C<insert_time> accessor return a |
59 | L<DateTime> object. This L<DateTime> object is later "deflated" when |
60 | used in the database layer. |
61 | |
62 | =cut |
63 | |
0e5c2582 |
64 | sub inflate_column { |
65 | my ($self, $col, $attrs) = @_; |
bc0c9800 |
66 | $self->throw_exception("No such column $col to inflate") |
67 | unless $self->has_column($col); |
68 | $self->throw_exception("inflate_column needs attr hashref") |
69 | unless ref $attrs eq 'HASH'; |
103647d5 |
70 | $self->column_info($col)->{_inflate_info} = $attrs; |
0e5c2582 |
71 | $self->mk_group_accessors('inflated_column' => $col); |
72 | return 1; |
73 | } |
74 | |
4a07648a |
75 | sub _inflated_column { |
0e5c2582 |
76 | my ($self, $col, $value) = @_; |
9f300b1b |
77 | return $value unless defined $value; # NULL is NULL is NULL |
bc0c9800 |
78 | my $info = $self->column_info($col) |
79 | or $self->throw_exception("No column info for $col"); |
103647d5 |
80 | return $value unless exists $info->{_inflate_info}; |
81 | my $inflate = $info->{_inflate_info}{inflate}; |
701da8c4 |
82 | $self->throw_exception("No inflator for $col") unless defined $inflate; |
0e5c2582 |
83 | return $inflate->($value, $self); |
84 | } |
85 | |
180c7679 |
86 | sub _deflate_column { |
87 | my ($self, $col) = @_; |
88 | return if exists $self->{_column_data}{$col}; |
89 | my $value = $self->{_inflated_column}{$col}; |
90 | if (ref $value) { |
91 | my $info = $self->column_info($col) or |
92 | $self->throw_exception("No column info for $col"); |
93 | if (exists $info->{_inflate_info}) { |
94 | my $deflate = $info->{_inflate_info}{deflate}; |
95 | $self->throw_exception("No deflator for $col") unless defined $deflate; |
96 | $value = $deflate->($value, $self); |
97 | } |
98 | } |
99 | $self->store_column($col, $value); |
0e5c2582 |
100 | } |
101 | |
7eb4ecc8 |
102 | =head2 get_inflated_column |
103 | |
104 | my $val = $obj->get_inflated_column($col); |
105 | |
106 | Fetch a column value in its inflated state. This is directly |
107 | analogous to L<DBIx::Class::Row/get_column> in that it only fetches a |
108 | column already retreived from the database, and then inflates it. |
109 | Throws an exception if the column requested is not an inflated column. |
110 | |
111 | =cut |
112 | |
0e5c2582 |
113 | sub get_inflated_column { |
114 | my ($self, $col) = @_; |
bc0c9800 |
115 | $self->throw_exception("$col is not an inflated column") |
116 | unless exists $self->column_info($col)->{_inflate_info}; |
4a07648a |
117 | |
0e5c2582 |
118 | return $self->{_inflated_column}{$col} |
119 | if exists $self->{_inflated_column}{$col}; |
0e5c2582 |
120 | return $self->{_inflated_column}{$col} = |
4a07648a |
121 | $self->_inflated_column($col, $self->get_column($col)); |
0e5c2582 |
122 | } |
123 | |
7eb4ecc8 |
124 | =head2 set_inflated_column |
125 | |
126 | my $copy = $obj->set_inflated_column($col => $val); |
127 | |
128 | Sets a column value from an inflated value. This is directly |
129 | analogous to L<DBIx::Class::Row/set_column>. |
130 | |
131 | =cut |
132 | |
0e5c2582 |
133 | sub set_inflated_column { |
180c7679 |
134 | my ($self, $col, $obj) = @_; |
135 | my $old = $self->get_inflated_column($col); |
136 | my $ret = $self->store_inflated_column($col, $obj); |
137 | $self->{_dirty_columns}{$col} = 1 |
138 | if (defined $old ^ defined $ret) || (defined $old && $old ne $ret); |
0e5c2582 |
139 | return $ret; |
140 | } |
141 | |
7eb4ecc8 |
142 | =head2 store_inflated_column |
143 | |
144 | my $copy = $obj->store_inflated_column($col => $val); |
145 | |
146 | Sets a column value from an inflated value without marking the column |
47c56124 |
147 | as dirty. This is directly analogous to L<DBIx::Class::Row/store_column>. |
7eb4ecc8 |
148 | |
149 | =cut |
150 | |
0e5c2582 |
151 | sub store_inflated_column { |
180c7679 |
152 | my ($self, $col, $obj) = @_; |
47c56124 |
153 | if (ref $obj) { |
154 | delete $self->{_column_data}{$col}; |
155 | return $self->{_inflated_column}{$col} = $obj; |
156 | } else { |
0e5c2582 |
157 | delete $self->{_inflated_column}{$col}; |
47c56124 |
158 | return $self->store_column($col, $obj); |
0e5c2582 |
159 | } |
180c7679 |
160 | } |
4a07648a |
161 | |
47c56124 |
162 | =head2 get_column |
163 | |
164 | Gets a column value in the same way as L<DBIx::Class::Row/get_column>. If there |
165 | is an inflated value stored that has not yet been deflated, it is deflated |
166 | when the method is invoked. |
167 | |
168 | =cut |
169 | |
180c7679 |
170 | sub get_column { |
171 | my ($self, $col) = @_; |
172 | $self->_deflate_column($col); |
173 | return $self->next::method($col); |
174 | } |
4a07648a |
175 | |
180c7679 |
176 | sub get_columns { |
177 | my $self = shift; |
178 | if (exists $self->{_inflated_column}) { |
179 | $self->_deflate_column($_) for keys %{$self->{_inflated_column}}; |
180 | } |
181 | return $self->next::method; |
182 | } |
183 | |
184 | sub has_column_loaded { |
185 | my ($self, $col) = @_; |
186 | return 1 if exists $self->{_inflated_column}{$col}; |
187 | return $self->next::method($col); |
0e5c2582 |
188 | } |
189 | |
7eb4ecc8 |
190 | =head2 update |
191 | |
192 | Updates a row in the same way as L<DBIx::Class::Row/update>, handling |
193 | inflation and deflation of columns appropriately. |
194 | |
195 | =cut |
196 | |
9fcda149 |
197 | sub update { |
198 | my ($class, $attrs, @rest) = @_; |
180c7679 |
199 | foreach my $key (keys %{$attrs||{}}) { |
9fcda149 |
200 | if (ref $attrs->{$key} |
201 | && exists $class->column_info($key)->{_inflate_info}) { |
180c7679 |
202 | $class->set_inflated_column($key, delete $attrs->{$key}); |
9fcda149 |
203 | } |
204 | } |
205 | return $class->next::method($attrs, @rest); |
206 | } |
207 | |
7eb4ecc8 |
208 | =head2 new |
209 | |
210 | Creates a row in the same way as L<DBIx::Class::Row/new>, handling |
211 | inflation and deflation of columns appropriately. |
212 | |
213 | =cut |
214 | |
0e5c2582 |
215 | sub new { |
216 | my ($class, $attrs, @rest) = @_; |
180c7679 |
217 | my $inflated; |
218 | foreach my $key (keys %{$attrs||{}}) { |
219 | $inflated->{$key} = delete $attrs->{$key} |
220 | if ref $attrs->{$key} && exists $class->column_info($key)->{_inflate_info}; |
0e5c2582 |
221 | } |
180c7679 |
222 | my $obj = $class->next::method($attrs, @rest); |
223 | $obj->{_inflated_column} = $inflated if $inflated; |
224 | return $obj; |
0e5c2582 |
225 | } |
226 | |
bcae85db |
227 | =head1 SEE ALSO |
228 | |
229 | =over 4 |
230 | |
231 | =item L<DBIx::Class::Core> - This component is loaded as part of the |
232 | "core" L<DBIx::Class> components; generally there is no need to |
233 | load it directly |
234 | |
235 | =back |
236 | |
237 | =head1 AUTHOR |
238 | |
239 | Matt S. Trout <mst@shadowcatsystems.co.uk> |
240 | |
241 | =head1 CONTRIBUTORS |
242 | |
243 | Daniel Westermann-Clark <danieltwc@cpan.org> (documentation) |
244 | |
245 | =head1 LICENSE |
246 | |
247 | You may distribute this code under the same terms as Perl itself. |
248 | |
249 | =cut |
250 | |
0e5c2582 |
251 | 1; |