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9c992ba1 |
1 | package DBIx::Class::ResultSource; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | |
6 | use DBIx::Class::ResultSet; |
7 | |
8 | use Carp qw/croak/; |
9 | |
6da5894c |
10 | use Storable; |
11 | |
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12 | use base qw/DBIx::Class/; |
13 | __PACKAGE__->load_components(qw/AccessorGroup/); |
14 | |
15 | __PACKAGE__->mk_group_accessors('simple' => |
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16 | qw/_ordered_columns _columns _primaries _unique_constraints name resultset_class result_class schema from _relationships/); |
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17 | |
18 | =head1 NAME |
19 | |
20 | DBIx::Class::ResultSource - Result source object |
21 | |
22 | =head1 SYNOPSIS |
23 | |
24 | =head1 DESCRIPTION |
25 | |
26 | A ResultSource is a component of a schema from which results can be directly |
27 | retrieved, most usually a table (see L<DBIx::Class::ResultSource::Table>) |
28 | |
29 | =head1 METHODS |
30 | |
31 | =cut |
32 | |
33 | sub new { |
34 | my ($class, $attrs) = @_; |
35 | $class = ref $class if ref $class; |
36 | my $new = bless({ %{$attrs || {}} }, $class); |
37 | $new->{resultset_class} ||= 'DBIx::Class::ResultSet'; |
6da5894c |
38 | $new->{_ordered_columns} = [ @{$new->{_ordered_columns}||[]}]; |
39 | $new->{_columns} = { %{$new->{_columns}||{}} }; |
40 | $new->{_relationships} = { %{$new->{_relationships}||{}} }; |
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41 | $new->{name} ||= "!!NAME NOT SET!!"; |
42 | return $new; |
43 | } |
44 | |
45 | sub add_columns { |
46 | my ($self, @cols) = @_; |
571dced3 |
47 | $self->_ordered_columns( \@cols ) |
48 | if !$self->_ordered_columns; |
20518cb4 |
49 | my @added; |
50 | my $columns = $self->_columns; |
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51 | while (my $col = shift @cols) { |
53509665 |
52 | |
30126ac7 |
53 | my $column_info = ref $cols[0] ? shift(@cols) : {}; |
53509665 |
54 | # If next entry is { ... } use that for the column info, if not |
55 | # use an empty hashref |
56 | |
20518cb4 |
57 | push(@added, $col) unless exists $columns->{$col}; |
58 | |
59 | $columns->{$col} = $column_info; |
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60 | } |
20518cb4 |
61 | push @{ $self->_ordered_columns }, @added; |
30126ac7 |
62 | return $self; |
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63 | } |
64 | |
65 | *add_column = \&add_columns; |
66 | |
67 | =head2 add_columns |
68 | |
69 | $table->add_columns(qw/col1 col2 col3/); |
70 | |
71 | $table->add_columns('col1' => \%col1_info, 'col2' => \%col2_info, ...); |
72 | |
73 | Adds columns to the result source. If supplied key => hashref pairs uses |
74 | the hashref as the column_info for that column. |
75 | |
76 | =head2 add_column |
77 | |
78 | $table->add_column('col' => \%info?); |
79 | |
80 | Convenience alias to add_columns |
81 | |
82 | =cut |
83 | |
84 | sub resultset { |
85 | my $self = shift; |
86 | return $self->resultset_class->new($self); |
87 | } |
88 | |
3842b955 |
89 | =head2 has_column |
90 | |
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91 | if ($obj->has_column($col)) { ... } |
92 | |
93 | Returns 1 if the source has a column of this name, 0 otherwise. |
94 | |
95 | =cut |
96 | |
97 | sub has_column { |
98 | my ($self, $column) = @_; |
99 | return exists $self->_columns->{$column}; |
100 | } |
101 | |
102 | =head2 column_info |
103 | |
104 | my $info = $obj->column_info($col); |
105 | |
106 | Returns the column metadata hashref for a column. |
107 | |
108 | =cut |
109 | |
110 | sub column_info { |
111 | my ($self, $column) = @_; |
112 | croak "No such column $column" unless exists $self->_columns->{$column}; |
a953d8d9 |
113 | if ( (! $self->_columns->{$column}->{data_type}) |
114 | && $self->schema && $self->storage() ){ |
115 | my $info; |
116 | ############ eval for the case of storage without table |
117 | eval{ |
118 | $info = $self->storage->columns_info_for ( $self->from() ); |
119 | }; |
120 | if ( ! $@ ){ |
121 | for my $col ( keys %{$self->_columns} ){ |
122 | for my $i ( keys %{$info->{$col}} ){ |
123 | $self->_columns()->{$col}->{$i} = $info->{$col}->{$i}; |
124 | } |
125 | } |
126 | } |
127 | } |
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128 | return $self->_columns->{$column}; |
129 | } |
130 | |
131 | =head2 columns |
132 | |
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133 | my @column_names = $obj->columns; |
134 | |
135 | Returns all column names in the order they were declared to add_columns |
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136 | |
137 | =cut |
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138 | |
139 | sub columns { |
140 | croak "columns() is a read-only accessor, did you mean add_columns()?" if (@_ > 1); |
571dced3 |
141 | return @{shift->{_ordered_columns}||[]}; |
142 | } |
143 | |
87f0da6a |
144 | =head2 set_primary_key(@cols) |
145 | |
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146 | Defines one or more columns as primary key for this source. Should be |
147 | called after C<add_columns>. |
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148 | |
149 | Additionally, defines a unique constraint named C<primary>. |
150 | |
151 | =cut |
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152 | |
153 | sub set_primary_key { |
154 | my ($self, @cols) = @_; |
155 | # check if primary key columns are valid columns |
156 | for (@cols) { |
157 | $self->throw("No such column $_ on table ".$self->name) |
158 | unless $self->has_column($_); |
159 | } |
160 | $self->_primaries(\@cols); |
87f0da6a |
161 | |
162 | $self->add_unique_constraint(primary => \@cols); |
9c992ba1 |
163 | } |
164 | |
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165 | =head2 primary_columns |
166 | |
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167 | Read-only accessor which returns the list of primary keys. |
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168 | |
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169 | =cut |
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170 | |
171 | sub primary_columns { |
172 | return @{shift->_primaries||[]}; |
173 | } |
174 | |
87f0da6a |
175 | =head2 add_unique_constraint |
176 | |
177 | Declare a unique constraint on this source. Call once for each unique |
178 | constraint. |
179 | |
180 | # For e.g. UNIQUE (column1, column2) |
181 | __PACKAGE__->add_unique_constraint(constraint_name => [ qw/column1 column2/ ]); |
182 | |
183 | =cut |
184 | |
185 | sub add_unique_constraint { |
186 | my ($self, $name, $cols) = @_; |
187 | |
188 | for (@$cols) { |
189 | $self->throw("No such column $_ on table ".$self->name) |
190 | unless $self->has_column($_); |
191 | } |
192 | |
193 | my %unique_constraints = $self->unique_constraints; |
194 | $unique_constraints{$name} = $cols; |
195 | $self->_unique_constraints(\%unique_constraints); |
196 | } |
197 | |
198 | =head2 unique_constraints |
199 | |
200 | Read-only accessor which returns the list of unique constraints on this source. |
201 | |
202 | =cut |
203 | |
204 | sub unique_constraints { |
205 | return %{shift->_unique_constraints||{}}; |
206 | } |
207 | |
9c992ba1 |
208 | =head2 from |
209 | |
210 | Returns an expression of the source to be supplied to storage to specify |
211 | retrieval from this source; in the case of a database the required FROM clause |
212 | contents. |
213 | |
214 | =cut |
215 | |
216 | =head2 storage |
217 | |
218 | Returns the storage handle for the current schema |
219 | |
220 | =cut |
221 | |
222 | sub storage { shift->schema->storage; } |
223 | |
8452e496 |
224 | =head2 add_relationship |
225 | |
226 | $source->add_relationship('relname', 'related_source', $cond, $attrs); |
227 | |
228 | The relation name can be arbitrary, but must be unique for each relationship |
229 | attached to this result source. 'related_source' should be the name with |
230 | which the related result source was registered with the current schema |
231 | (for simple schemas this is usally either Some::Namespace::Foo or just Foo) |
232 | |
233 | The condition needs to be an SQL::Abstract-style representation of the join |
234 | between the tables. For example, if you're creating a rel from Foo to Bar, |
235 | |
236 | { 'foreign.foo_id' => 'self.id' } |
237 | |
238 | will result in the JOIN clause |
239 | |
240 | foo me JOIN bar bar ON bar.foo_id = me.id |
241 | |
242 | You can specify as many foreign => self mappings as necessary. |
243 | |
244 | Valid attributes are as follows: |
245 | |
246 | =over 4 |
247 | |
248 | =item join_type |
249 | |
250 | Explicitly specifies the type of join to use in the relationship. Any SQL |
251 | join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in the SQL |
252 | command immediately before C<JOIN>. |
253 | |
254 | =item proxy |
255 | |
256 | An arrayref containing a list of accessors in the foreign class to proxy in |
257 | the main class. If, for example, you do the following: |
258 | |
259 | __PACKAGE__->might_have(bar => 'Bar', undef, { proxy => qw[/ margle /] }); |
260 | |
261 | Then, assuming Bar has an accessor named margle, you can do: |
262 | |
263 | my $obj = Foo->find(1); |
264 | $obj->margle(10); # set margle; Bar object is created if it doesn't exist |
265 | |
266 | =item accessor |
267 | |
268 | Specifies the type of accessor that should be created for the relationship. |
269 | Valid values are C<single> (for when there is only a single related object), |
270 | C<multi> (when there can be many), and C<filter> (for when there is a single |
271 | related object, but you also want the relationship accessor to double as |
272 | a column accessor). For C<multi> accessors, an add_to_* method is also |
273 | created, which calls C<create_related> for the relationship. |
274 | |
275 | =back |
276 | |
277 | =cut |
278 | |
279 | sub add_relationship { |
280 | my ($self, $rel, $f_source_name, $cond, $attrs) = @_; |
aa562407 |
281 | croak "Can't create relationship without join condition" unless $cond; |
8452e496 |
282 | $attrs ||= {}; |
87772e46 |
283 | |
8452e496 |
284 | my %rels = %{ $self->_relationships }; |
285 | $rels{$rel} = { class => $f_source_name, |
87772e46 |
286 | source => $f_source_name, |
8452e496 |
287 | cond => $cond, |
288 | attrs => $attrs }; |
289 | $self->_relationships(\%rels); |
290 | |
30126ac7 |
291 | return $self; |
87772e46 |
292 | |
953a18ef |
293 | # XXX disabled. doesn't work properly currently. skip in tests. |
294 | |
8452e496 |
295 | my $f_source = $self->schema->source($f_source_name); |
296 | unless ($f_source) { |
297 | eval "require $f_source_name;"; |
298 | if ($@) { |
299 | die $@ unless $@ =~ /Can't locate/; |
300 | } |
301 | $f_source = $f_source_name->result_source; |
87772e46 |
302 | #my $s_class = ref($self->schema); |
303 | #$f_source_name =~ m/^${s_class}::(.*)$/; |
304 | #$self->schema->register_class(($1 || $f_source_name), $f_source_name); |
305 | #$f_source = $self->schema->source($f_source_name); |
8452e496 |
306 | } |
307 | return unless $f_source; # Can't test rel without f_source |
308 | |
309 | eval { $self->resolve_join($rel, 'me') }; |
310 | |
311 | if ($@) { # If the resolve failed, back out and re-throw the error |
312 | delete $rels{$rel}; # |
313 | $self->_relationships(\%rels); |
aa562407 |
314 | croak "Error creating relationship $rel: $@"; |
8452e496 |
315 | } |
316 | 1; |
317 | } |
318 | |
319 | =head2 relationships() |
320 | |
321 | Returns all valid relationship names for this source |
322 | |
323 | =cut |
324 | |
325 | sub relationships { |
326 | return keys %{shift->_relationships}; |
327 | } |
328 | |
329 | =head2 relationship_info($relname) |
330 | |
331 | Returns the relationship information for the specified relationship name |
332 | |
333 | =cut |
334 | |
335 | sub relationship_info { |
336 | my ($self, $rel) = @_; |
337 | return $self->_relationships->{$rel}; |
338 | } |
339 | |
953a18ef |
340 | =head2 has_relationship($rel) |
341 | |
342 | Returns 1 if the source has a relationship of this name, 0 otherwise. |
343 | |
344 | =cut |
345 | |
346 | sub has_relationship { |
347 | my ($self, $rel) = @_; |
348 | return exists $self->_relationships->{$rel}; |
349 | } |
350 | |
8452e496 |
351 | =head2 resolve_join($relation) |
352 | |
353 | Returns the join structure required for the related result source |
354 | |
355 | =cut |
356 | |
357 | sub resolve_join { |
87772e46 |
358 | my ($self, $join, $alias) = @_; |
359 | if (ref $join eq 'ARRAY') { |
360 | return map { $self->resolve_join($_, $alias) } @$join; |
361 | } elsif (ref $join eq 'HASH') { |
362 | return map { $self->resolve_join($_, $alias), |
363 | $self->related_source($_)->resolve_join($join->{$_}, $_) } |
364 | keys %$join; |
365 | } elsif (ref $join) { |
aa562407 |
366 | croak ("No idea how to resolve join reftype ".ref $join); |
87772e46 |
367 | } else { |
3842b955 |
368 | my $rel_info = $self->relationship_info($join); |
aa562407 |
369 | croak("No such relationship ${join}") unless $rel_info; |
3842b955 |
370 | my $type = $rel_info->{attrs}{join_type} || ''; |
953a18ef |
371 | return [ { $join => $self->related_source($join)->from, |
372 | -join_type => $type }, |
3842b955 |
373 | $self->resolve_condition($rel_info->{cond}, $join, $alias) ]; |
953a18ef |
374 | } |
375 | } |
376 | |
3842b955 |
377 | =head2 resolve_condition($cond, $rel, $alias|$object) |
953a18ef |
378 | |
3842b955 |
379 | Resolves the passed condition to a concrete query fragment. If given an alias, |
953a18ef |
380 | returns a join condition; if given an object, inverts that object to produce |
381 | a related conditional from that object. |
382 | |
383 | =cut |
384 | |
385 | sub resolve_condition { |
3842b955 |
386 | my ($self, $cond, $rel, $for) = @_; |
953a18ef |
387 | #warn %$cond; |
388 | if (ref $cond eq 'HASH') { |
389 | my %ret; |
390 | while (my ($k, $v) = each %{$cond}) { |
391 | # XXX should probably check these are valid columns |
aa562407 |
392 | $k =~ s/^foreign\.// || croak "Invalid rel cond key ${k}"; |
393 | $v =~ s/^self\.// || croak "Invalid rel cond val ${v}"; |
953a18ef |
394 | if (ref $for) { # Object |
3842b955 |
395 | #warn "$self $k $for $v"; |
396 | $ret{$k} = $for->get_column($v); |
397 | #warn %ret; |
953a18ef |
398 | } else { |
3842b955 |
399 | $ret{"${rel}.${k}"} = "${for}.${v}"; |
953a18ef |
400 | } |
953a18ef |
401 | } |
402 | return \%ret; |
5efe4c79 |
403 | } elsif (ref $cond eq 'ARRAY') { |
404 | return [ map { $self->resolve_condition($_, $rel, $for) } @$cond ]; |
953a18ef |
405 | } else { |
406 | die("Can't handle this yet :("); |
87772e46 |
407 | } |
408 | } |
409 | |
b3e8ac9b |
410 | =head2 resolve_prefetch (hashref/arrayref/scalar) |
411 | |
412 | Accepts one or more relationships for the current source and returns an |
413 | array of column names for each of those relationships. Column names are |
414 | prefixed relative to the current source, in accordance with where they appear |
415 | in the supplied relationships. Examples: |
416 | |
417 | my $source = $schema->$resultset('Tag')->source; |
418 | @columns = $source->resolve_prefetch( { cd => 'artist' } ); |
419 | |
420 | # @columns = |
421 | #( |
422 | # 'cd.cdid', |
423 | # 'cd.artist', |
424 | # 'cd.title', |
425 | # 'cd.year', |
426 | # 'cd.artist.artistid', |
427 | # 'cd.artist.name' |
428 | #) |
429 | |
430 | @columns = $source->resolve_prefetch( qw[/ cd /] ); |
431 | |
432 | # @columns = |
433 | #( |
434 | # 'cd.cdid', |
435 | # 'cd.artist', |
436 | # 'cd.title', |
437 | # 'cd.year' |
438 | #) |
439 | |
440 | $source = $schema->resultset('CD')->source; |
441 | @columns = $source->resolve_prefetch( qw[/ artist producer /] ); |
442 | |
443 | # @columns = |
444 | #( |
445 | # 'artist.artistid', |
446 | # 'artist.name', |
447 | # 'producer.producerid', |
448 | # 'producer.name' |
449 | #) |
450 | |
451 | =cut |
452 | |
453 | sub resolve_prefetch { |
454 | my( $self, $pre, $alias ) = @_; |
455 | use Data::Dumper; |
456 | #$alias ||= $self->name; |
457 | #warn $alias, Dumper $pre; |
458 | if( ref $pre eq 'ARRAY' ) { |
459 | return map { $self->resolve_prefetch( $_, $alias ) } @$pre; |
460 | } |
461 | elsif( ref $pre eq 'HASH' ) { |
462 | my @ret = |
463 | map { |
464 | $self->resolve_prefetch($_, $alias), |
465 | $self->related_source($_)->resolve_prefetch( $pre->{$_}, $_ ) |
466 | } |
467 | keys %$pre; |
468 | #die Dumper \@ret; |
469 | return @ret; |
470 | } |
471 | elsif( ref $pre ) { |
472 | croak( "don't know how to resolve prefetch reftype " . ref $pre); |
473 | } |
474 | else { |
475 | my $rel_info = $self->relationship_info( $pre ); |
476 | croak( $self->name . " has no such relationship '$pre'" ) unless $rel_info; |
477 | my $prefix = $alias && $alias ne 'me' ? "$alias.$pre" : $pre; |
478 | my @ret = map { "$prefix.$_" } $self->related_source($pre)->columns; |
479 | #warn $alias, Dumper (\@ret); |
480 | return @ret; |
481 | } |
482 | } |
953a18ef |
483 | |
87772e46 |
484 | =head2 related_source($relname) |
485 | |
486 | Returns the result source for the given relationship |
487 | |
488 | =cut |
489 | |
490 | sub related_source { |
491 | my ($self, $rel) = @_; |
aea52c85 |
492 | if( !$self->has_relationship( $rel ) ) { |
493 | croak "No such relationship '$rel'"; |
494 | } |
87772e46 |
495 | return $self->schema->source($self->relationship_info($rel)->{source}); |
8452e496 |
496 | } |
497 | |
9c992ba1 |
498 | 1; |
499 | |
500 | =head1 AUTHORS |
501 | |
502 | Matt S. Trout <mst@shadowcatsystems.co.uk> |
503 | |
504 | =head1 LICENSE |
505 | |
506 | You may distribute this code under the same terms as Perl itself. |
507 | |
508 | =cut |
509 | |