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55e2d745 |
1 | package DBIx::Class::Relationship::Base; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | |
1edd1722 |
6 | use base qw/DBIx::Class/; |
6298a324 |
7 | |
8 | use Scalar::Util qw/weaken blessed/; |
ed7ab0f4 |
9 | use Try::Tiny; |
fd323bf1 |
10 | use namespace::clean; |
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11 | |
75d07914 |
12 | =head1 NAME |
55e2d745 |
13 | |
8918977e |
14 | DBIx::Class::Relationship::Base - Inter-table relationships |
55e2d745 |
15 | |
16 | =head1 SYNOPSIS |
17 | |
13523f29 |
18 | __PACKAGE__->add_relationship('spiders', |
19 | 'My::DB::Result::Creatures', |
20 | sub { |
21 | my ( $me_alias, $rel_alias) = @_; |
22 | return |
23 | { "${rel_alias}.id" => { '=' => \"${me_alias}.id"}, |
24 | "${rel_alias}.type" => { '=', "arachnid" }, |
25 | }; |
26 | |
27 | }); |
28 | |
55e2d745 |
29 | =head1 DESCRIPTION |
30 | |
30236e47 |
31 | This class provides methods to describe the relationships between the |
32 | tables in your database model. These are the "bare bones" relationships |
75d07914 |
33 | methods, for predefined ones, look in L<DBIx::Class::Relationship>. |
55e2d745 |
34 | |
35 | =head1 METHODS |
36 | |
8091aa91 |
37 | =head2 add_relationship |
503536d5 |
38 | |
27f01d1f |
39 | =over 4 |
40 | |
13523f29 |
41 | =item Arguments: 'relname', 'Foreign::Class', $condition, $attrs |
27f01d1f |
42 | |
43 | =back |
30236e47 |
44 | |
13523f29 |
45 | __PACKAGE__->add_relationship('relname', |
46 | 'Foreign::Class', |
47 | $condition, $attrs); |
48 | |
49 | Create a custom relationship between one result source and another |
50 | source, indicated by its class name. |
503536d5 |
51 | |
406734bb |
52 | =head3 condition |
53 | |
13523f29 |
54 | The condition argument describes the JOIN expression used to connect |
55 | the two sources when creating SQL queries. |
30236e47 |
56 | |
13523f29 |
57 | To create simple equality joins, supply a hashref containing the |
58 | remote table column name as the key(s), and the local table column |
59 | name as the value(s), for example: |
503536d5 |
60 | |
30236e47 |
61 | { 'foreign.author_id' => 'self.id' } |
503536d5 |
62 | |
13523f29 |
63 | will result in the C<JOIN> clause: |
503536d5 |
64 | |
5271499d |
65 | author me JOIN book book ON book.author_id = me.id |
503536d5 |
66 | |
13523f29 |
67 | This describes a relationship between the C<Author> table and the |
68 | C<Book> table where the C<Book> table has a column C<author_id> |
69 | containing the ID value of the C<Author>. |
70 | |
71 | C<foreign> and C<self> are psuedo aliases and must be entered |
72 | literally. They will be replaced with the actual correct table alias |
73 | when the SQL is produced. |
74 | |
75 | Similarly: |
5271499d |
76 | |
77 | { |
781102cd |
78 | 'foreign.publisher_id' => 'self.publisher_id', |
5271499d |
79 | 'foreign.type_id' => 'self.type_id', |
80 | } |
81 | |
13523f29 |
82 | will result in the C<JOIN> clause: |
5271499d |
83 | |
84 | book me JOIN edition edition ON edition.publisher_id = me.publisher_id |
85 | AND edition.type_id = me.type_id |
86 | |
13523f29 |
87 | This describes the relationship from C<Book> to C<Edition>, where the |
88 | C<Edition> table refers to a publisher and a type (e.g. "paperback"): |
89 | |
90 | As is the default in L<SQL::Abstract>, the key-value pairs will be |
91 | C<AND>ed in the result. C<OR> can be achieved with an arrayref, for |
92 | example: |
93 | |
94 | [ |
95 | { 'foreign.left_itemid' => 'self.id' }, |
96 | { 'foreign.right_itemid' => 'self.id' }, |
97 | ] |
98 | |
99 | which results in the C<JOIN> clause: |
100 | |
101 | items me JOIN related_items rel_link ON rel_link.left_itemid = me.id |
102 | OR rel_link.right_itemid = me.id |
103 | |
104 | This describes the relationship from C<Items> to C<RelatedItems>, |
105 | where C<RelatedItems> is a many-to-many linking table, linking Items |
106 | back to themselves. |
107 | |
108 | To create joins which describe more than a simple equality of column |
109 | values, the custom join condition coderef syntax can be used: |
110 | |
111 | sub { |
112 | my ( $me_alias, $rel_alias ) = @_; |
113 | return |
114 | ({ "${rel_alias}.artist" => { '=' => \"${me_alias}.artistid"}, |
115 | "${rel_alias}.year" => { '>', "1979", |
116 | '<', "1990" } |
117 | }); |
118 | } |
119 | |
120 | this will result in the C<JOIN> clause: |
121 | |
122 | artist me LEFT JOIN cd cds_80s_noopt ON |
123 | ( cds_80s_noopt.artist = me.artistid |
124 | AND ( cds_80s_noopt.year < ? AND cds_80s_noopt.year > ? ) |
125 | ) |
126 | |
127 | with the bind values: |
128 | |
129 | '1990', '1979' |
130 | |
131 | C<$rel_alias> is the equivalent to C<foreign> in the simple syntax, |
132 | and will be replaced by the actual remote table alias in the produced |
133 | SQL. Similarly, C<$me_alias> is the equivalent to C<self> and will be |
134 | replaced with the local table alias in the SQL. |
135 | |
136 | The actual syntax returned by the coderef should be valid |
137 | L<SQL::Abstract> syntax, similar to normal |
138 | L<DBIx::Class::ResultSet/search> conditions. |
139 | |
140 | To help optimise the SQL produced, a second optional hashref can be |
141 | returned to be used when the relationship accessor is called directly |
142 | on a Row object: |
143 | |
144 | sub { |
145 | my ( $me_alias, $rel_alias, $me_result_source, |
146 | $rel_name, $optional_me_object ) = @_; |
147 | return |
148 | ({ "${rel_alias}.artist" => { '=' => \"${me_alias}.artistid"}, |
149 | "${rel_alias}.year" => { '>', "1979", |
150 | '<', "1990" } |
151 | }, |
152 | $optional_me_object && |
153 | { "${rel_alias}.artist" => $optional_me_object->artistid, |
154 | "${rel_alias}.year" => { '>', "1979", |
155 | '<', "1990" } |
156 | }); |
157 | } |
158 | |
159 | Now this code: |
160 | |
161 | my $artist = $schema->resultset("Artist")->find({ id => 4 }); |
162 | $artist->cds_80s->all; |
163 | |
164 | Produces: |
165 | |
166 | SELECT me.cdid, me.artist, me.title, me.year, me.genreid, me.single_track |
167 | FROM cd me |
168 | WHERE ( ( me.artist = ? AND ( me.year < ? AND me.year > ? ) ) ) |
169 | |
170 | With the bind values: |
171 | |
172 | '4', '1990', '1979' |
173 | |
174 | The C<$optional_me_object> used to create the second hashref contains |
175 | a row object, the object that the relation accessor was called on. |
176 | |
177 | C<$me_result_source> the L<DBIx::Class::ResultSource> of the table |
178 | being searched on, and C<$rel_name>, the name of the relation |
179 | containing this condition, are also provided as arguments. These may |
180 | be useful to more complicated condition calculation. |
8091aa91 |
181 | |
406734bb |
182 | =head3 attributes |
183 | |
184 | The L<standard ResultSet attributes|DBIx::Class::ResultSet/ATTRIBUTES> may |
185 | be used as relationship attributes. In particular, the 'where' attribute is |
186 | useful for filtering relationships: |
187 | |
188 | __PACKAGE__->has_many( 'valid_users', 'MyApp::Schema::User', |
189 | { 'foreign.user_id' => 'self.user_id' }, |
190 | { where => { valid => 1 } } |
191 | ); |
192 | |
193 | The following attributes are also valid: |
8091aa91 |
194 | |
195 | =over 4 |
196 | |
197 | =item join_type |
198 | |
199 | Explicitly specifies the type of join to use in the relationship. Any SQL |
200 | join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in the SQL |
201 | command immediately before C<JOIN>. |
202 | |
97c96475 |
203 | =item proxy =E<gt> $column | \@columns | \%column |
204 | |
205 | =over 4 |
206 | |
207 | =item \@columns |
8091aa91 |
208 | |
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209 | An arrayref containing a list of accessors in the foreign class to create in |
8091aa91 |
210 | the main class. If, for example, you do the following: |
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211 | |
27f01d1f |
212 | MyDB::Schema::CD->might_have(liner_notes => 'MyDB::Schema::LinerNotes', |
213 | undef, { |
214 | proxy => [ qw/notes/ ], |
215 | }); |
d4daee7b |
216 | |
30236e47 |
217 | Then, assuming MyDB::Schema::LinerNotes has an accessor named notes, you can do: |
8091aa91 |
218 | |
30236e47 |
219 | my $cd = MyDB::Schema::CD->find(1); |
220 | $cd->notes('Notes go here'); # set notes -- LinerNotes object is |
221 | # created if it doesn't exist |
d4daee7b |
222 | |
97c96475 |
223 | =item \%column |
224 | |
225 | A hashref where each key is the accessor you want installed in the main class, |
226 | and its value is the name of the original in the fireign class. |
227 | |
228 | MyDB::Schema::Track->belongs_to( cd => 'DBICTest::Schema::CD', 'cd', { |
229 | proxy => { cd_title => 'title' }, |
230 | }); |
231 | |
232 | This will create an accessor named C<cd_title> on the C<$track> row object. |
233 | |
234 | =back |
235 | |
236 | NOTE: you can pass a nested struct too, for example: |
237 | |
238 | MyDB::Schema::Track->belongs_to( cd => 'DBICTest::Schema::CD', 'cd', { |
239 | proxy => [ 'year', { cd_title => 'title' } ], |
240 | }); |
241 | |
8091aa91 |
242 | =item accessor |
243 | |
244 | Specifies the type of accessor that should be created for the relationship. |
245 | Valid values are C<single> (for when there is only a single related object), |
246 | C<multi> (when there can be many), and C<filter> (for when there is a single |
247 | related object, but you also want the relationship accessor to double as |
248 | a column accessor). For C<multi> accessors, an add_to_* method is also |
249 | created, which calls C<create_related> for the relationship. |
250 | |
3d618782 |
251 | =item is_foreign_key_constraint |
252 | |
253 | If you are using L<SQL::Translator> to create SQL for you and you find that it |
fd323bf1 |
254 | is creating constraints where it shouldn't, or not creating them where it |
3d618782 |
255 | should, set this attribute to a true or false value to override the detection |
256 | of when to create constraints. |
257 | |
5f7ac523 |
258 | =item cascade_copy |
259 | |
260 | If C<cascade_copy> is true on a C<has_many> relationship for an |
261 | object, then when you copy the object all the related objects will |
fd323bf1 |
262 | be copied too. To turn this behaviour off, pass C<< cascade_copy => 0 >> |
263 | in the C<$attr> hashref. |
b7bbc39f |
264 | |
265 | The behaviour defaults to C<< cascade_copy => 1 >> for C<has_many> |
266 | relationships. |
5f7ac523 |
267 | |
268 | =item cascade_delete |
269 | |
b7bbc39f |
270 | By default, DBIx::Class cascades deletes across C<has_many>, |
271 | C<has_one> and C<might_have> relationships. You can disable this |
fd323bf1 |
272 | behaviour on a per-relationship basis by supplying |
b7bbc39f |
273 | C<< cascade_delete => 0 >> in the relationship attributes. |
5f7ac523 |
274 | |
275 | The cascaded operations are performed after the requested delete, |
276 | so if your database has a constraint on the relationship, it will |
277 | have deleted/updated the related records or raised an exception |
278 | before DBIx::Class gets to perform the cascaded operation. |
279 | |
280 | =item cascade_update |
281 | |
b7bbc39f |
282 | By default, DBIx::Class cascades updates across C<has_one> and |
5f7ac523 |
283 | C<might_have> relationships. You can disable this behaviour on a |
b7bbc39f |
284 | per-relationship basis by supplying C<< cascade_update => 0 >> in |
285 | the relationship attributes. |
5f7ac523 |
286 | |
cee0c9b1 |
287 | This is not a RDMS style cascade update - it purely means that when |
288 | an object has update called on it, all the related objects also |
289 | have update called. It will not change foreign keys automatically - |
290 | you must arrange to do this yourself. |
5f7ac523 |
291 | |
e377d723 |
292 | =item on_delete / on_update |
293 | |
294 | If you are using L<SQL::Translator> to create SQL for you, you can use these |
fd323bf1 |
295 | attributes to explicitly set the desired C<ON DELETE> or C<ON UPDATE> constraint |
296 | type. If not supplied the SQLT parser will attempt to infer the constraint type by |
e377d723 |
297 | interrogating the attributes of the B<opposite> relationship. For any 'multi' |
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298 | relationship with C<< cascade_delete => 1 >>, the corresponding belongs_to |
299 | relationship will be created with an C<ON DELETE CASCADE> constraint. For any |
e377d723 |
300 | relationship bearing C<< cascade_copy => 1 >> the resulting belongs_to constraint |
301 | will be C<ON UPDATE CASCADE>. If you wish to disable this autodetection, and just |
fd323bf1 |
302 | use the RDBMS' default constraint type, pass C<< on_delete => undef >> or |
e377d723 |
303 | C<< on_delete => '' >>, and the same for C<on_update> respectively. |
304 | |
13de943d |
305 | =item is_deferrable |
306 | |
307 | Tells L<SQL::Translator> that the foreign key constraint it creates should be |
308 | deferrable. In other words, the user may request that the constraint be ignored |
309 | until the end of the transaction. Currently, only the PostgreSQL producer |
310 | actually supports this. |
311 | |
2581038c |
312 | =item add_fk_index |
313 | |
314 | Tells L<SQL::Translator> to add an index for this constraint. Can also be |
315 | specified globally in the args to L<DBIx::Class::Schema/deploy> or |
316 | L<DBIx::Class::Schema/create_ddl_dir>. Default is on, set to 0 to disable. |
317 | |
8091aa91 |
318 | =back |
319 | |
87c4e602 |
320 | =head2 register_relationship |
321 | |
27f01d1f |
322 | =over 4 |
323 | |
ebc77b53 |
324 | =item Arguments: $relname, $rel_info |
27f01d1f |
325 | |
326 | =back |
71e65b39 |
327 | |
30236e47 |
328 | Registers a relationship on the class. This is called internally by |
71f9df37 |
329 | DBIx::Class::ResultSourceProxy to set up Accessors and Proxies. |
71e65b39 |
330 | |
55e2d745 |
331 | =cut |
332 | |
71e65b39 |
333 | sub register_relationship { } |
334 | |
27f01d1f |
335 | =head2 related_resultset |
336 | |
337 | =over 4 |
338 | |
ebc77b53 |
339 | =item Arguments: $relationship_name |
27f01d1f |
340 | |
d601dc88 |
341 | =item Return Value: $related_resultset |
27f01d1f |
342 | |
343 | =back |
30236e47 |
344 | |
27f01d1f |
345 | $rs = $cd->related_resultset('artist'); |
30236e47 |
346 | |
27f01d1f |
347 | Returns a L<DBIx::Class::ResultSet> for the relationship named |
348 | $relationship_name. |
30236e47 |
349 | |
350 | =cut |
351 | |
352 | sub related_resultset { |
353 | my $self = shift; |
bc0c9800 |
354 | $self->throw_exception("Can't call *_related as class methods") |
355 | unless ref $self; |
30236e47 |
356 | my $rel = shift; |
164efde3 |
357 | my $rel_info = $self->relationship_info($rel); |
bc0c9800 |
358 | $self->throw_exception( "No such relationship ${rel}" ) |
164efde3 |
359 | unless $rel_info; |
d4daee7b |
360 | |
30236e47 |
361 | return $self->{related_resultsets}{$rel} ||= do { |
362 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
164efde3 |
363 | $attrs = { %{$rel_info->{attrs} || {}}, %$attrs }; |
30236e47 |
364 | |
bc0c9800 |
365 | $self->throw_exception( "Invalid query: @_" ) |
366 | if (@_ > 1 && (@_ % 2 == 1)); |
30236e47 |
367 | my $query = ((@_ > 1) ? {@_} : shift); |
368 | |
68f3b0dd |
369 | my $source = $self->result_source; |
d419ded6 |
370 | |
371 | # condition resolution may fail if an incomplete master-object prefetch |
34b6b86f |
372 | # is encountered - that is ok during prefetch construction (not yet in_storage) |
a126983e |
373 | |
374 | # if $rel_info->{cond} is a CODE, we might need to join from the |
375 | # current resultsource instead of just querying the target |
376 | # resultsource, in that case, the condition might provide an |
377 | # additional condition in order to avoid an unecessary join if |
378 | # that is at all possible. |
9aae3566 |
379 | my ($cond, $extended_cond) = try { |
52b420dd |
380 | $source->_resolve_condition( $rel_info->{cond}, $rel, $self ) |
381 | } |
ed7ab0f4 |
382 | catch { |
34b6b86f |
383 | if ($self->in_storage) { |
ed7ab0f4 |
384 | $self->throw_exception ($_); |
34b6b86f |
385 | } |
52b420dd |
386 | |
387 | $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION; # RV |
ed7ab0f4 |
388 | }; |
d419ded6 |
389 | |
68f3b0dd |
390 | if ($cond eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) { |
391 | my $reverse = $source->reverse_relationship_info($rel); |
392 | foreach my $rev_rel (keys %$reverse) { |
b82c8a28 |
393 | if ($reverse->{$rev_rel}{attrs}{accessor} && $reverse->{$rev_rel}{attrs}{accessor} eq 'multi') { |
2c5c07ec |
394 | $attrs->{related_objects}{$rev_rel} = [ $self ]; |
6298a324 |
395 | weaken $attrs->{related_object}{$rev_rel}[0]; |
2c5c07ec |
396 | } else { |
397 | $attrs->{related_objects}{$rev_rel} = $self; |
6298a324 |
398 | weaken $attrs->{related_object}{$rev_rel}; |
2c5c07ec |
399 | } |
68f3b0dd |
400 | } |
401 | } |
9aae3566 |
402 | |
403 | # this is where we're going to check if we have an extended |
404 | # rel. In that case, we need to: 1) If there's a second |
405 | # condition, we use that instead. 2) If there is only one |
406 | # condition, we need to join the current resultsource and have |
407 | # additional conditions. |
408 | if (ref $rel_info->{cond} eq 'CODE') { |
409 | # this is an extended relationship. |
410 | if ($extended_cond) { |
411 | $cond = $extended_cond; |
412 | |
413 | } else { |
414 | |
415 | # it's a bit hard to find out what to do with other joins |
416 | $self->throw_exception('Extended relationship '.$rel.' with additional join requires optimized declaration') |
417 | if exists $attrs->{join} && $attrs->{join}; |
418 | |
419 | # aliases get a bit more complicated, so we won't accept additional queries |
420 | $self->throw_exception('Extended relationship '.$rel.' with additional query requires optimized declaration') |
421 | if $query; |
422 | |
423 | $attrs->{from} = |
424 | [ { $rel => $self->result_source->from }, |
425 | [ { 'me' => $self->result_source->related_source($rel)->from }, { 1 => 1 } ] ]; |
426 | |
427 | $cond->{"${rel}.${_}"} = $self->get_column($_) for $self->result_source->primary_columns; |
428 | } |
429 | } |
430 | |
30236e47 |
431 | if (ref $cond eq 'ARRAY') { |
370f2ba2 |
432 | $cond = [ map { |
433 | if (ref $_ eq 'HASH') { |
434 | my $hash; |
435 | foreach my $key (keys %$_) { |
47752afe |
436 | my $newkey = $key !~ /\./ ? "me.$key" : $key; |
370f2ba2 |
437 | $hash->{$newkey} = $_->{$key}; |
438 | } |
439 | $hash; |
440 | } else { |
441 | $_; |
442 | } |
443 | } @$cond ]; |
68f3b0dd |
444 | } elsif (ref $cond eq 'HASH') { |
9aae3566 |
445 | foreach my $key (grep { ! /\./ } keys %$cond) { |
446 | $cond->{"me.$key"} = delete $cond->{$key}; |
30236e47 |
447 | } |
448 | } |
a126983e |
449 | |
30236e47 |
450 | $query = ($query ? { '-and' => [ $cond, $query ] } : $cond); |
bc0c9800 |
451 | $self->result_source->related_source($rel)->resultset->search( |
452 | $query, $attrs |
453 | ); |
30236e47 |
454 | }; |
455 | } |
456 | |
8091aa91 |
457 | =head2 search_related |
503536d5 |
458 | |
5b89a768 |
459 | @objects = $rs->search_related('relname', $cond, $attrs); |
460 | $objects_rs = $rs->search_related('relname', $cond, $attrs); |
30236e47 |
461 | |
462 | Run a search on a related resultset. The search will be restricted to the |
463 | item or items represented by the L<DBIx::Class::ResultSet> it was called |
464 | upon. This method can be called on a ResultSet, a Row or a ResultSource class. |
503536d5 |
465 | |
466 | =cut |
467 | |
55e2d745 |
468 | sub search_related { |
ff7bb7a1 |
469 | return shift->related_resultset(shift)->search(@_); |
b52e9bf8 |
470 | } |
471 | |
5b89a768 |
472 | =head2 search_related_rs |
473 | |
474 | ( $objects_rs ) = $rs->search_related_rs('relname', $cond, $attrs); |
475 | |
fd323bf1 |
476 | This method works exactly the same as search_related, except that |
48580715 |
477 | it guarantees a resultset, even in list context. |
5b89a768 |
478 | |
479 | =cut |
480 | |
481 | sub search_related_rs { |
482 | return shift->related_resultset(shift)->search_rs(@_); |
483 | } |
484 | |
b52e9bf8 |
485 | =head2 count_related |
486 | |
7be93b07 |
487 | $obj->count_related('relname', $cond, $attrs); |
b52e9bf8 |
488 | |
bc0c9800 |
489 | Returns the count of all the items in the related resultset, restricted by the |
490 | current item or where conditions. Can be called on a |
27f01d1f |
491 | L<DBIx::Class::Manual::Glossary/"ResultSet"> or a |
bc0c9800 |
492 | L<DBIx::Class::Manual::Glossary/"Row"> object. |
30236e47 |
493 | |
b52e9bf8 |
494 | =cut |
495 | |
496 | sub count_related { |
497 | my $self = shift; |
498 | return $self->search_related(@_)->count; |
55e2d745 |
499 | } |
500 | |
30236e47 |
501 | =head2 new_related |
502 | |
503 | my $new_obj = $obj->new_related('relname', \%col_data); |
504 | |
505 | Create a new item of the related foreign class. If called on a |
fd323bf1 |
506 | L<Row|DBIx::Class::Manual::Glossary/"Row"> object, it will magically |
507 | set any foreign key columns of the new object to the related primary |
508 | key columns of the source object for you. The newly created item will |
479b2a6a |
509 | not be saved into your storage until you call L<DBIx::Class::Row/insert> |
30236e47 |
510 | on it. |
511 | |
512 | =cut |
513 | |
514 | sub new_related { |
515 | my ($self, $rel, $values, $attrs) = @_; |
516 | return $self->search_related($rel)->new($values, $attrs); |
517 | } |
518 | |
8091aa91 |
519 | =head2 create_related |
503536d5 |
520 | |
30236e47 |
521 | my $new_obj = $obj->create_related('relname', \%col_data); |
522 | |
523 | Creates a new item, similarly to new_related, and also inserts the item's data |
524 | into your storage medium. See the distinction between C<create> and C<new> |
525 | in L<DBIx::Class::ResultSet> for details. |
503536d5 |
526 | |
527 | =cut |
528 | |
55e2d745 |
529 | sub create_related { |
3842b955 |
530 | my $self = shift; |
fea3d045 |
531 | my $rel = shift; |
64acc2bc |
532 | my $obj = $self->search_related($rel)->create(@_); |
533 | delete $self->{related_resultsets}->{$rel}; |
534 | return $obj; |
55e2d745 |
535 | } |
536 | |
8091aa91 |
537 | =head2 find_related |
503536d5 |
538 | |
30236e47 |
539 | my $found_item = $obj->find_related('relname', @pri_vals | \%pri_vals); |
540 | |
541 | Attempt to find a related object using its primary key or unique constraints. |
27f01d1f |
542 | See L<DBIx::Class::ResultSet/find> for details. |
503536d5 |
543 | |
544 | =cut |
545 | |
1a14aa3f |
546 | sub find_related { |
547 | my $self = shift; |
548 | my $rel = shift; |
716b3d29 |
549 | return $self->search_related($rel)->find(@_); |
1a14aa3f |
550 | } |
551 | |
b3e1f1f5 |
552 | =head2 find_or_new_related |
553 | |
554 | my $new_obj = $obj->find_or_new_related('relname', \%col_data); |
555 | |
556 | Find an item of a related class. If none exists, instantiate a new item of the |
557 | related class. The object will not be saved into your storage until you call |
558 | L<DBIx::Class::Row/insert> on it. |
559 | |
560 | =cut |
561 | |
562 | sub find_or_new_related { |
563 | my $self = shift; |
e60dc79f |
564 | my $obj = $self->find_related(@_); |
565 | return defined $obj ? $obj : $self->new_related(@_); |
b3e1f1f5 |
566 | } |
567 | |
8091aa91 |
568 | =head2 find_or_create_related |
503536d5 |
569 | |
30236e47 |
570 | my $new_obj = $obj->find_or_create_related('relname', \%col_data); |
571 | |
27f01d1f |
572 | Find or create an item of a related class. See |
b3e1f1f5 |
573 | L<DBIx::Class::ResultSet/find_or_create> for details. |
503536d5 |
574 | |
575 | =cut |
576 | |
55e2d745 |
577 | sub find_or_create_related { |
578 | my $self = shift; |
9c2c91ea |
579 | my $obj = $self->find_related(@_); |
580 | return (defined($obj) ? $obj : $self->create_related(@_)); |
55e2d745 |
581 | } |
582 | |
045120e6 |
583 | =head2 update_or_create_related |
584 | |
585 | my $updated_item = $obj->update_or_create_related('relname', \%col_data, \%attrs?); |
586 | |
587 | Update or create an item of a related class. See |
f7e1846f |
588 | L<DBIx::Class::ResultSet/update_or_create> for details. |
045120e6 |
589 | |
590 | =cut |
591 | |
592 | sub update_or_create_related { |
593 | my $self = shift; |
594 | my $rel = shift; |
595 | return $self->related_resultset($rel)->update_or_create(@_); |
596 | } |
597 | |
8091aa91 |
598 | =head2 set_from_related |
503536d5 |
599 | |
30236e47 |
600 | $book->set_from_related('author', $author_obj); |
ac8e89d7 |
601 | $book->author($author_obj); ## same thing |
30236e47 |
602 | |
603 | Set column values on the current object, using related values from the given |
604 | related object. This is used to associate previously separate objects, for |
605 | example, to set the correct author for a book, find the Author object, then |
606 | call set_from_related on the book. |
607 | |
ac8e89d7 |
608 | This is called internally when you pass existing objects as values to |
48580715 |
609 | L<DBIx::Class::ResultSet/create>, or pass an object to a belongs_to accessor. |
ac8e89d7 |
610 | |
27f01d1f |
611 | The columns are only set in the local copy of the object, call L</update> to |
612 | set them in the storage. |
503536d5 |
613 | |
614 | =cut |
615 | |
55e2d745 |
616 | sub set_from_related { |
617 | my ($self, $rel, $f_obj) = @_; |
164efde3 |
618 | my $rel_info = $self->relationship_info($rel); |
619 | $self->throw_exception( "No such relationship ${rel}" ) unless $rel_info; |
620 | my $cond = $rel_info->{cond}; |
bc0c9800 |
621 | $self->throw_exception( |
622 | "set_from_related can only handle a hash condition; the ". |
623 | "condition for $rel is of type ". |
624 | (ref $cond ? ref $cond : 'plain scalar') |
625 | ) unless ref $cond eq 'HASH'; |
2c037e6b |
626 | if (defined $f_obj) { |
164efde3 |
627 | my $f_class = $rel_info->{class}; |
2c037e6b |
628 | $self->throw_exception( "Object $f_obj isn't a ".$f_class ) |
6298a324 |
629 | unless blessed $f_obj and $f_obj->isa($f_class); |
2c037e6b |
630 | } |
a126983e |
631 | |
632 | # _resolve_condition might return two hashrefs, specially in the |
633 | # current case, since we know $f_object is an object. |
634 | my ($condref1, $condref2) = $self->result_source->_resolve_condition |
635 | ($rel_info->{cond}, $f_obj, $rel); |
636 | |
637 | # if we get two condrefs, we need to use the second, otherwise we |
638 | # use the first. |
639 | $self->set_columns($condref2 ? $condref2 : $condref1); |
640 | |
55e2d745 |
641 | return 1; |
642 | } |
643 | |
8091aa91 |
644 | =head2 update_from_related |
503536d5 |
645 | |
30236e47 |
646 | $book->update_from_related('author', $author_obj); |
647 | |
27f01d1f |
648 | The same as L</"set_from_related">, but the changes are immediately updated |
649 | in storage. |
503536d5 |
650 | |
651 | =cut |
652 | |
55e2d745 |
653 | sub update_from_related { |
654 | my $self = shift; |
655 | $self->set_from_related(@_); |
656 | $self->update; |
657 | } |
658 | |
8091aa91 |
659 | =head2 delete_related |
503536d5 |
660 | |
30236e47 |
661 | $obj->delete_related('relname', $cond, $attrs); |
662 | |
663 | Delete any related item subject to the given conditions. |
503536d5 |
664 | |
665 | =cut |
666 | |
55e2d745 |
667 | sub delete_related { |
668 | my $self = shift; |
64acc2bc |
669 | my $obj = $self->search_related(@_)->delete; |
670 | delete $self->{related_resultsets}->{$_[0]}; |
671 | return $obj; |
55e2d745 |
672 | } |
673 | |
ec353f53 |
674 | =head2 add_to_$rel |
675 | |
676 | B<Currently only available for C<has_many>, C<many-to-many> and 'multi' type |
677 | relationships.> |
678 | |
679 | =over 4 |
680 | |
681 | =item Arguments: ($foreign_vals | $obj), $link_vals? |
682 | |
683 | =back |
684 | |
685 | my $role = $schema->resultset('Role')->find(1); |
686 | $actor->add_to_roles($role); |
687 | # creates a My::DBIC::Schema::ActorRoles linking table row object |
688 | |
689 | $actor->add_to_roles({ name => 'lead' }, { salary => 15_000_000 }); |
690 | # creates a new My::DBIC::Schema::Role row object and the linking table |
691 | # object with an extra column in the link |
692 | |
693 | Adds a linking table object for C<$obj> or C<$foreign_vals>. If the first |
694 | argument is a hash reference, the related object is created first with the |
695 | column values in the hash. If an object reference is given, just the linking |
696 | table object is created. In either case, any additional column values for the |
697 | linking table object can be specified in C<$link_vals>. |
698 | |
699 | =head2 set_$rel |
700 | |
701 | B<Currently only available for C<many-to-many> relationships.> |
702 | |
703 | =over 4 |
704 | |
ac36a402 |
705 | =item Arguments: (\@hashrefs | \@objs), $link_vals? |
ec353f53 |
706 | |
707 | =back |
708 | |
709 | my $actor = $schema->resultset('Actor')->find(1); |
fd323bf1 |
710 | my @roles = $schema->resultset('Role')->search({ role => |
debccec3 |
711 | { '-in' => ['Fred', 'Barney'] } } ); |
ec353f53 |
712 | |
4d3a827d |
713 | $actor->set_roles(\@roles); |
714 | # Replaces all of $actor's previous roles with the two named |
ec353f53 |
715 | |
ac36a402 |
716 | $actor->set_roles(\@roles, { salary => 15_000_000 }); |
717 | # Sets a column in the link table for all roles |
718 | |
719 | |
4d3a827d |
720 | Replace all the related objects with the given reference to a list of |
721 | objects. This does a C<delete> B<on the link table resultset> to remove the |
722 | association between the current object and all related objects, then calls |
723 | C<add_to_$rel> repeatedly to link all the new objects. |
bba68c67 |
724 | |
725 | Note that this means that this method will B<not> delete any objects in the |
726 | table on the right side of the relation, merely that it will delete the link |
727 | between them. |
ec353f53 |
728 | |
4d3a827d |
729 | Due to a mistake in the original implementation of this method, it will also |
730 | accept a list of objects or hash references. This is B<deprecated> and will be |
731 | removed in a future version. |
732 | |
ec353f53 |
733 | =head2 remove_from_$rel |
734 | |
735 | B<Currently only available for C<many-to-many> relationships.> |
736 | |
737 | =over 4 |
738 | |
739 | =item Arguments: $obj |
740 | |
741 | =back |
742 | |
743 | my $role = $schema->resultset('Role')->find(1); |
744 | $actor->remove_from_roles($role); |
745 | # removes $role's My::DBIC::Schema::ActorRoles linking table row object |
746 | |
747 | Removes the link between the current object and the related object. Note that |
748 | the related object itself won't be deleted unless you call ->delete() on |
749 | it. This method just removes the link between the two objects. |
750 | |
55e2d745 |
751 | =head1 AUTHORS |
752 | |
daec44b8 |
753 | Matt S. Trout <mst@shadowcatsystems.co.uk> |
55e2d745 |
754 | |
755 | =head1 LICENSE |
756 | |
757 | You may distribute this code under the same terms as Perl itself. |
758 | |
759 | =cut |
760 | |
4d87db01 |
761 | 1; |