added docs about treatment of belongs_to, might_have and has_many relationships
[chaz/p5-DBIx-Class-ResultSet-RecursiveUpdate] / lib / DBIx / Class / ResultSet / RecursiveUpdate.pm
1 use strict;
2 use warnings;
3 package DBIx::Class::ResultSet::RecursiveUpdate;
4
5 our $VERSION = '0.013';
6
7 use base qw(DBIx::Class::ResultSet);
8
9 sub recursive_update {
10 my ( $self, $updates, $fixed_fields ) = @_;
11 return DBIx::Class::ResultSet::RecursiveUpdate::Functions::recursive_update(
12 resultset => $self,
13 updates => $updates,
14 fixed_fields => $fixed_fields
15 );
16 }
17
18 package DBIx::Class::ResultSet::RecursiveUpdate::Functions;
19 use Carp;
20 use Scalar::Util qw( blessed );
21
22
23 sub recursive_update {
24 my %params = @_;
25 my ( $self, $updates, $fixed_fields, $object, $resolved, $if_not_submitted ) = @params{ qw/resultset updates fixed_fields object resolved if_not_submitted/ };
26 $resolved ||= {};
27 # warn 'entering: ' . $self->result_source->from();
28 carp 'fixed fields needs to be an array ref' if $fixed_fields && ref($fixed_fields) ne 'ARRAY';
29 my %fixed_fields;
30 %fixed_fields = map { $_ => 1 } @$fixed_fields if $fixed_fields;
31 if ( blessed($updates) && $updates->isa('DBIx::Class::Row') ) {
32 return $updates;
33 }
34 if ( $updates->{id} ){
35 $object = $self->find( $updates->{id}, { key => 'primary' } );
36 }
37 my @missing =
38 grep { !exists $updates->{$_} && !exists $fixed_fields{$_} } $self->result_source->primary_columns;
39 if ( !$object && !scalar @missing ) {
40 # warn 'finding by: ' . Dumper( $updates ); use Data::Dumper;
41 $object = $self->find( $updates, { key => 'primary' } );
42 }
43 $updates = { %$updates, %$resolved };
44 @missing =
45 grep { !exists $resolved->{$_} } @missing;
46 if ( !$object && !scalar @missing ) {
47 # warn 'finding by +resolved: ' . Dumper( $updates ); use Data::Dumper;
48 $object = $self->find( $updates, { key => 'primary' } );
49 }
50 $object ||= $self->new( {} );
51 # warn Dumper( $updates ); use Data::Dumper;
52 # direct column accessors
53 my %columns;
54
55 # relations that that should be done before the row is inserted into the database
56 # like belongs_to
57 my %pre_updates;
58
59 # relations that that should be done after the row is inserted into the database
60 # like has_many, might_have and has_one
61 my %post_updates;
62 my %other_methods;
63 my %columns_by_accessor = _get_columns_by_accessor( $self );
64 # warn 'resolved: ' . Dumper( $resolved );
65 # warn 'updates: ' . Dumper( $updates ); use Data::Dumper;
66 # warn 'columns: ' . Dumper( \%columns_by_accessor );
67 for my $name ( keys %$updates ) {
68 my $source = $self->result_source;
69 if ( $columns_by_accessor{$name}
70 && !( $source->has_relationship($name) && ref( $updates->{$name} ) )
71 )
72 {
73 $columns{$name} = $updates->{$name};
74 next;
75 }
76 if( !( $source->has_relationship($name) ) ){
77 $other_methods{$name} = $updates->{$name};
78 next;
79 }
80 my $info = $source->relationship_info($name);
81 if (
82 _master_relation_cond(
83 $source, $info->{cond}, _get_pk_for_related( $self, $name)
84 )
85 )
86 {
87 $pre_updates{$name} = $updates->{$name};
88 }
89 else {
90 $post_updates{$name} = $updates->{$name};
91 }
92 }
93 # warn 'other: ' . Dumper( \%other_methods ); use Data::Dumper;
94
95 # first update columns and other accessors - so that later related records can be found
96 for my $name ( keys %columns ) {
97 $object->$name( $columns{$name} );
98 }
99 for my $name ( keys %other_methods) {
100 $object->$name( $updates->{$name} ) if $object->can( $name );
101 }
102 for my $name ( keys %pre_updates ) {
103 my $info = $object->result_source->relationship_info($name);
104 _update_relation( $self, $name, $updates, $object, $info, $if_not_submitted );
105 }
106 # $self->_delete_empty_auto_increment($object);
107 # don't allow insert to recurse to related objects - we do the recursion ourselves
108 # $object->{_rel_in_storage} = 1;
109
110 $object->update_or_insert if $object->is_changed;
111
112 # updating many_to_many
113 for my $name ( keys %$updates ) {
114 next if exists $columns{$name};
115 my $value = $updates->{$name};
116
117 if ( is_m2m( $self, $name) ) {
118 my ($pk) = _get_pk_for_related( $self, $name);
119 my @rows;
120 my $result_source = $object->$name->result_source;
121 my @updates;
122 if( ! defined $value ){
123 next;
124 }
125 elsif( ref $value ){
126 @updates = @{ $value };
127 }
128 else{
129 @updates = ( $value );
130 }
131 for my $elem ( @updates ) {
132 if ( ref $elem ) {
133 push @rows, recursive_update( resultset => $result_source->resultset, updates => $elem );
134 }
135 else {
136 push @rows,
137 $result_source->resultset->find( { $pk => $elem } );
138 }
139 }
140 my $set_meth = 'set_' . $name;
141 $object->$set_meth( \@rows );
142 }
143 }
144 for my $name ( keys %post_updates ) {
145 my $info = $object->result_source->relationship_info($name);
146 _update_relation( $self, $name, $updates, $object, $info, $if_not_submitted );
147 }
148 return $object;
149 }
150
151 # returns DBIx::Class::ResultSource::column_info as a hash indexed by column accessor || name
152 sub _get_columns_by_accessor {
153 my $self = shift;
154 my $source = $self->result_source;
155 my %columns;
156 for my $name ( $source->columns ) {
157 my $info = $source->column_info($name);
158 $info->{name} = $name;
159 $columns{ $info->{accessor} || $name } = $info;
160 }
161 return %columns;
162 }
163
164 sub _update_relation {
165 my ( $self, $name, $updates, $object, $info, $if_not_submitted ) = @_;
166 my $related_result =
167 $self->related_resultset($name)->result_source->resultset;
168 my $resolved;
169 if( $self->result_source->can( '_resolve_condition' ) ){
170 $resolved = $self->result_source->_resolve_condition( $info->{cond}, $name, $object );
171 }
172 else{
173 $resolved = $self->result_source->resolve_condition( $info->{cond}, $name, $object );
174 }
175
176 # warn 'resolved: ' . Dumper( $resolved ); use Data::Dumper;
177 $resolved = {}
178 if defined $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION && $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION == $resolved;
179 if ( ref $updates->{$name} eq 'ARRAY' ) {
180 my @updated_ids;
181 for my $sub_updates ( @{ $updates->{$name} } ) {
182 my $sub_object =
183 recursive_update( resultset => $related_result, updates => $sub_updates, resolved => $resolved );
184 push @updated_ids, $sub_object->id;
185 }
186 my @related_pks = $related_result->result_source->primary_columns;
187 if( defined $if_not_submitted && $if_not_submitted eq 'delete' ){
188 # only handles related result classes with single primary keys
189 if ( 1 == scalar @related_pks ){
190 $object->$name->search( { $related_pks[0] => { -not_in => \@updated_ids } } )->delete;
191 }
192 }
193 elsif( defined $if_not_submitted && $if_not_submitted eq 'set_to_null' ){
194 # only handles related result classes with single primary keys
195 if ( 1 == scalar @related_pks ){
196 my @fk = keys %$resolved;
197 $object->$name->search( { $related_pks[0] => { -not_in => \@updated_ids } } )->update( { $fk[0] => undef } );
198 }
199 }
200 }
201 else {
202 my $sub_updates = $updates->{$name};
203 my $sub_object;
204 if( ref $sub_updates ){
205 # for might_have relationship
206 if( $info->{attrs}{accessor} eq 'single' && defined $object->$name ){
207 $sub_object = recursive_update(
208 resultset => $related_result,
209 updates => $sub_updates,
210 object => $object->$name
211 );
212 }
213 else{
214 $sub_object =
215 recursive_update( resultset => $related_result, updates => $sub_updates, resolved => $resolved );
216 }
217 }
218 elsif( ! ref $sub_updates ){
219 $sub_object = $related_result->find( $sub_updates )
220 unless (!$sub_updates && (exists $info->{attrs}{join_type} && $info->{attrs}{join_type} eq 'LEFT'));
221 }
222 $object->set_from_related( $name, $sub_object )
223 unless (!$sub_object && !$sub_updates && (exists $info->{attrs}{join_type} && $info->{attrs}{join_type} eq 'LEFT'));
224 }
225 }
226
227 sub is_m2m {
228 my ( $self, $relation ) = @_;
229 my $rclass = $self->result_class;
230
231 # DBIx::Class::IntrospectableM2M
232 if ( $rclass->can('_m2m_metadata') ) {
233 return $rclass->_m2m_metadata->{$relation};
234 }
235 my $object = $self->new( {} );
236 if ( $object->can($relation)
237 and !$self->result_source->has_relationship($relation)
238 and $object->can( 'set_' . $relation ) )
239 {
240 return 1;
241 }
242 return;
243 }
244
245 sub get_m2m_source {
246 my ( $self, $relation ) = @_;
247 my $rclass = $self->result_class;
248
249 # DBIx::Class::IntrospectableM2M
250 if ( $rclass->can('_m2m_metadata') ) {
251 return $self->result_source->related_source(
252 $rclass->_m2m_metadata->{$relation}{relation} )
253 ->related_source(
254 $rclass->_m2m_metadata->{$relation}{foreign_relation} );
255 }
256 my $object = $self->new( {} );
257 my $r = $object->$relation;
258 return $r->result_source;
259 }
260
261 sub _delete_empty_auto_increment {
262 my ( $self, $object ) = @_;
263 for my $col ( keys %{ $object->{_column_data} } ) {
264 if (
265 $object->result_source->column_info($col)->{is_auto_increment}
266 and ( !defined $object->{_column_data}{$col}
267 or $object->{_column_data}{$col} eq '' )
268 )
269 {
270 delete $object->{_column_data}{$col};
271 }
272 }
273 }
274
275 sub _get_pk_for_related {
276 my ( $self, $relation ) = @_;
277 my $result_source;
278 if ( $self->result_source->has_relationship($relation) ) {
279 $result_source = $self->result_source->related_source($relation);
280 }
281
282 # many to many case
283 if ( is_m2m($self, $relation) ) {
284 $result_source = get_m2m_source($self, $relation);
285 }
286 return $result_source->primary_columns;
287 }
288
289 # This function determines wheter a relationship should be done before or
290 # after the row is inserted into the database
291 # relationships before: belongs_to
292 # relationships after: has_many, might_have and has_one
293 sub _master_relation_cond {
294 my ( $source, $cond, @foreign_ids ) = @_;
295 my $foreign_ids_re = join '|', @foreign_ids;
296 if ( ref $cond eq 'HASH' ) {
297 for my $f_key ( keys %{$cond} ) {
298
299 # might_have is not master
300 my $col = $cond->{$f_key};
301 $col =~ s/self\.//;
302 if ( $source->column_info($col)->{is_auto_increment} ) {
303 return 0;
304 }
305 if ( $f_key =~ /^foreign\.$foreign_ids_re/ ) {
306 return 1;
307 }
308 }
309 }
310 elsif ( ref $cond eq 'ARRAY' ) {
311 for my $new_cond (@$cond) {
312 return 1
313 if _master_relation_cond( $source, $new_cond, @foreign_ids );
314 }
315 }
316 return;
317 }
318
319 1; # Magic true value required at end of module
320 __END__
321
322 =head1 NAME
323
324 DBIx::Class::ResultSet::RecursiveUpdate - like update_or_create - but recursive
325
326 =head1 SYNOPSIS
327
328 The functional interface:
329
330 my $new_item = DBIx::Class::ResultSet::RecursiveUpdate::Functions::recursive_update({
331 resultset => $schema->resultset( 'Dvd' ),
332 updates => {
333 id => 1,
334 owned_dvds => [
335 {
336 title => 'One Flew Over the Cuckoo's Nest'
337 }
338 ]
339 }
340 });
341
342
343 As ResultSet subclass:
344
345 __PACKAGE__->load_namespaces( default_resultset_class => '+DBIx::Class::ResultSet::RecursiveUpdate' );
346
347 in the Schema file (see t/lib/DBSchema.pm). Or appriopriate 'use base' in the ResultSet classes.
348
349 Then:
350
351 my $user = $user_rs->recursive_update( {
352 id => 1,
353 owned_dvds => [
354 {
355 title => 'One Flew Over the Cuckoo's Nest'
356 }
357 ]
358 }
359 );
360
361
362 =head1 DESCRIPTION
363
364 This is still experimental. I've added a functional interface so that it can be used
365 in Form Processors and not require modification of the model.
366
367 You can feed the ->create method with a recursive datastructure and have the related records
368 created. Unfortunately you cannot do a similar thing with update_or_create - this module
369 tries to fill that void.
370
371 It is a base class for ResultSets providing just one method: recursive_update
372 which works just like update_or_create but can recursively update or create
373 data objects composed of multiple rows. All rows need to be identified by primary keys
374 - so you need to provide them in the update structure (unless they can be deduced from
375 the parent row - for example when you have a belongs_to relationship).
376 If not all colums comprising the primary key are specified - then a new row will be created,
377 with the expectation that the missing columns will be filled by it (as in the case of auto_increment
378 primary keys).
379
380
381 If the resultset itself stores an assignement for the primary key,
382 like in the case of:
383
384 my $restricted_rs = $user_rs->search( { id => 1 } );
385
386 then you need to inform recursive_update about additional predicate with a second argument:
387
388 my $user = $restricted_rs->recursive_update( {
389 owned_dvds => [
390 {
391 title => 'One Flew Over the Cuckoo's Nest'
392 }
393 ]
394 },
395 [ 'id' ]
396 );
397
398 This will work with a new DBIC release.
399
400 For a many_to_many (pseudo) relation you can supply a list of primary keys
401 from the other table - and it will link the record at hand to those and
402 only those records identified by them. This is convenient for handling web
403 forms with check boxes (or a SELECT box with multiple choice) that let you
404 update such (pseudo) relations.
405
406 For a description how to set up base classes for ResultSets see load_namespaces
407 in DBIx::Class::Schema.
408
409 =head1 DESIGN CHOICES
410
411 Columns and relationships which are excluded from the updates hashref aren't
412 touched at all.
413
414 =head2 Treatment of belongs_to relations
415
416 In case the relationship is included but undefined in the updates hashref,
417 all columns forming the relationship will be set to null.
418 If not all of them are nullable, DBIx::Class will throw an error.
419
420 Updating the relationship:
421
422 my $dvd = $dvd_rs->recursive_update( {
423 id => 1,
424 owner => $user->id,
425 });
426
427 Clearing the relationship (only works if cols are nullable!):
428
429 my $dvd = $dvd_rs->recursive_update( {
430 id => 1,
431 owner => undef,
432 });
433
434 =head2 Treatment of might_have relationships
435
436 In case the relationship is included but undefined in the updates hashref,
437 all columns forming the relationship will be set to null.
438
439 Updating the relationship:
440
441 my $user = $user_rs->recursive_update( {
442 id => 1,
443 address => {
444 street => "101 Main Street",
445 city => "Podunk",
446 state => "New York",
447 }
448 });
449
450 Clearing the relationship:
451
452 my $user = $user_rs->recursive_update( {
453 id => 1,
454 address => undef,
455 });
456
457 =head2 Treatment of has_many relations
458
459 In case the relationship is included but undefined or an empty array, the
460 related rows will be deleted or their foreign key column set to null depending
461 on if_not_submitted parameter (set_to_null or delete).
462 It defaults to undefined which skips both.
463
464 Updating the relationship:
465
466 Passing ids:
467
468 my $dvd = $dvd_rs->recursive_update( {
469 id => 1,
470 tags => [1, 2],
471 });
472
473 Passing hashrefs:
474
475 my $dvd = $dvd_rs->recursive_update( {
476 id => 1,
477 tags => [
478 {
479 id => 1,
480 file => 'file0'
481 },
482 {
483 id => 2,
484 file => 'file1',
485 },
486 ],
487 });
488
489 Passing objects:
490
491 TODO
492
493 You can even mix them:
494
495 my $dvd = $dvd_rs->recursive_update( {
496 id => 1,
497 tags => [ '2', { id => '3' } ],
498 });
499
500 Clearing the relationship:
501
502 my $dvd = $dvd_rs->recursive_update( {
503 id => 1,
504 tags => undef,
505 });
506
507 This is the same as passing an empty array:
508
509 my $dvd = $dvd_rs->recursive_update( {
510 id => 1,
511 tags => [],
512 });
513
514 =head2 Treatment of many-to-many pseudo relations
515
516 The function gets the information about m2m relations from DBIx::Class::IntrospectableM2M.
517 If it is not loaded in the ResultSource classes - then the code relies on the fact that:
518 if($object->can($name) and
519 !$object->result_source->has_relationship($name) and
520 $object->can( 'set_' . $name )
521 )
522
523 then $name must be a many to many pseudo relation. And that in a
524 similarly ugly was I find out what is the ResultSource of objects from
525 that many to many pseudo relation.
526
527
528 =head1 INTERFACE
529
530 =head1 METHODS
531
532 =head2 recursive_update
533
534 The method that does the work here.
535
536 =head2 is_m2m
537
538 $self->is_m2m( 'name ' ) - answers the question if 'name' is a many to many
539 (pseudo) relation on $self.
540
541 =head2 get_m2m_source
542
543 $self->get_m2m_source( 'name' ) - returns the ResultSource linked to by the many
544 to many (pseudo) relation 'name' from $self.
545
546
547 =head1 DIAGNOSTICS
548
549
550 =head1 CONFIGURATION AND ENVIRONMENT
551
552 DBIx::Class::RecursiveUpdate requires no configuration files or environment variables.
553
554 =head1 DEPENDENCIES
555
556 DBIx::Class
557
558 =head1 INCOMPATIBILITIES
559
560 None reported.
561
562
563 =head1 BUGS AND LIMITATIONS
564
565 No bugs have been reported.
566
567 Please report any bugs or feature requests to
568 C<bug-dbix-class-recursiveput@rt.cpan.org>, or through the web interface at
569 L<http://rt.cpan.org>.
570
571
572 =head1 AUTHOR
573
574 Zbigniew Lukasiak C<< <zby@cpan.org> >>
575 Influenced by code by Pedro Melo.
576
577 =head1 LICENCE AND COPYRIGHT
578
579 Copyright (c) 2008, Zbigniew Lukasiak C<< <zby@cpan.org> >>. All rights reserved.
580
581 This module is free software; you can redistribute it and/or
582 modify it under the same terms as Perl itself. See L<perlartistic>.
583
584
585 =head1 DISCLAIMER OF WARRANTY
586
587 BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
588 FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
589 OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
590 PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
591 EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
592 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
593 ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
594 YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
595 NECESSARY SERVICING, REPAIR, OR CORRECTION.
596
597 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
598 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
599 REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE
600 LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL,
601 OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
602 THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
603 RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
604 FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
605 SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
606 SUCH DAMAGES.
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