1 package DBIx::Class::ResultSource;
6 use DBIx::Class::ResultSet;
7 use Carp::Clan qw/^DBIx::Class/;
10 use base qw/DBIx::Class/;
11 __PACKAGE__->load_components(qw/AccessorGroup/);
13 __PACKAGE__->mk_group_accessors('simple' => qw/_ordered_columns
14 _columns _primaries _unique_constraints name resultset_attributes
15 schema from _relationships/);
17 __PACKAGE__->mk_group_accessors('component_class' => qw/resultset_class
22 DBIx::Class::ResultSource - Result source object
28 A ResultSource is a component of a schema from which results can be directly
29 retrieved, most usually a table (see L<DBIx::Class::ResultSource::Table>)
36 my ($class, $attrs) = @_;
37 $class = ref $class if ref $class;
38 my $new = bless({ %{$attrs || {}}, _resultset => undef }, $class);
39 $new->{resultset_class} ||= 'DBIx::Class::ResultSet';
40 $new->{resultset_attributes} = { %{$new->{resultset_attributes} || {}} };
41 $new->{_ordered_columns} = [ @{$new->{_ordered_columns}||[]}];
42 $new->{_columns} = { %{$new->{_columns}||{}} };
43 $new->{_relationships} = { %{$new->{_relationships}||{}} };
44 $new->{name} ||= "!!NAME NOT SET!!";
45 $new->{_columns_info_loaded} ||= 0;
53 $table->add_columns(qw/col1 col2 col3/);
55 $table->add_columns('col1' => \%col1_info, 'col2' => \%col2_info, ...);
57 Adds columns to the result source. If supplied key => hashref pairs, uses
58 the hashref as the column_info for that column. Repeated calls of this
59 method will add more columns, not replace them.
61 The contents of the column_info are not set in stone. The following
62 keys are currently recognised/used by DBIx::Class:
68 Use this to set the name of the accessor for this column. If unset,
69 the name of the column will be used.
73 This contains the column type. It is automatically filled by the
74 L<SQL::Translator::Producer::DBIx::Class::File> producer, and the
75 L<DBIx::Class::Schema::Loader> module. If you do not enter a
76 data_type, DBIx::Class will attempt to retrieve it from the
77 database for you, using L<DBI>'s column_info method. The values of this
78 key are typically upper-cased.
80 Currently there is no standard set of values for the data_type. Use
81 whatever your database supports.
85 The length of your column, if it is a column type that can have a size
86 restriction. This is currently not used by DBIx::Class.
90 Set this to a true value for a columns that is allowed to contain
91 NULL values. This is currently not used by DBIx::Class.
93 =item is_auto_increment
95 Set this to a true value for a column whose value is somehow
96 automatically set. This is used to determine which columns to empty
97 when cloning objects using C<copy>.
101 Set this to a true value for a column that contains a key from a
102 foreign table. This is currently not used by DBIx::Class.
106 Set this to the default value which will be inserted into a column
107 by the database. Can contain either a value or a function. This is
108 currently not used by DBIx::Class.
112 Set this on a primary key column to the name of the sequence used to
113 generate a new key value. If not specified, L<DBIx::Class::PK::Auto>
114 will attempt to retrieve the name of the sequence from the database
121 $table->add_column('col' => \%info?);
123 Convenience alias to add_columns.
128 my ($self, @cols) = @_;
129 $self->_ordered_columns(\@cols) unless $self->_ordered_columns;
132 my $columns = $self->_columns;
133 while (my $col = shift @cols) {
134 # If next entry is { ... } use that for the column info, if not
135 # use an empty hashref
136 my $column_info = ref $cols[0] ? shift(@cols) : {};
137 push(@added, $col) unless exists $columns->{$col};
138 $columns->{$col} = $column_info;
140 push @{ $self->_ordered_columns }, @added;
144 *add_column = \&add_columns;
148 if ($obj->has_column($col)) { ... }
150 Returns true if the source has a column of this name, false otherwise.
155 my ($self, $column) = @_;
156 return exists $self->_columns->{$column};
161 my $info = $obj->column_info($col);
163 Returns the column metadata hashref for a column. See the description
164 of add_column for information on the contents of the hashref.
169 my ($self, $column) = @_;
170 $self->throw_exception("No such column $column")
171 unless exists $self->_columns->{$column};
172 #warn $self->{_columns_info_loaded}, "\n";
173 if ( ! $self->_columns->{$column}{data_type}
174 and ! $self->{_columns_info_loaded}
175 and $self->schema and $self->storage )
177 $self->{_columns_info_loaded}++;
179 # eval for the case of storage without table
180 eval { $info = $self->storage->columns_info_for($self->from) };
182 foreach my $col ( keys %{$self->_columns} ) {
183 foreach my $i ( keys %{$info->{$col}} ) {
184 $self->_columns->{$col}{$i} = $info->{$col}{$i};
189 return $self->_columns->{$column};
194 my @column_names = $obj->columns;
196 Returns all column names in the order they were declared to add_columns.
202 $self->throw_exception(
203 "columns() is a read-only accessor, did you mean add_columns()?"
205 return @{$self->{_ordered_columns}||[]};
208 =head2 set_primary_key
212 =item Arguments: @cols
216 Defines one or more columns as primary key for this source. Should be
217 called after C<add_columns>.
219 Additionally, defines a unique constraint named C<primary>.
221 The primary key columns are used by L<DBIx::Class::PK::Auto> to
222 retrieve automatically created values from the database.
226 sub set_primary_key {
227 my ($self, @cols) = @_;
228 # check if primary key columns are valid columns
229 foreach my $col (@cols) {
230 $self->throw_exception("No such column $col on table " . $self->name)
231 unless $self->has_column($col);
233 $self->_primaries(\@cols);
235 $self->add_unique_constraint(primary => \@cols);
238 =head2 primary_columns
240 Read-only accessor which returns the list of primary keys.
244 sub primary_columns {
245 return @{shift->_primaries||[]};
248 =head2 add_unique_constraint
250 Declare a unique constraint on this source. Call once for each unique
251 constraint. Unique constraints are used when you call C<find> on a
252 L<DBIx::Class::ResultSet>. Only columns in the constraint are searched,
255 # For UNIQUE (column1, column2)
256 __PACKAGE__->add_unique_constraint(
257 constraint_name => [ qw/column1 column2/ ],
262 sub add_unique_constraint {
263 my ($self, $name, $cols) = @_;
265 foreach my $col (@$cols) {
266 $self->throw_exception("No such column $col on table " . $self->name)
267 unless $self->has_column($col);
270 my %unique_constraints = $self->unique_constraints;
271 $unique_constraints{$name} = $cols;
272 $self->_unique_constraints(\%unique_constraints);
275 =head2 unique_constraints
277 Read-only accessor which returns the list of unique constraints on this source.
281 sub unique_constraints {
282 return %{shift->_unique_constraints||{}};
287 Returns an expression of the source to be supplied to storage to specify
288 retrieval from this source. In the case of a database, the required FROM
295 Returns the storage handle for the current schema.
297 See also: L<DBIx::Class::Storage>
301 sub storage { shift->schema->storage; }
303 =head2 add_relationship
305 $source->add_relationship('relname', 'related_source', $cond, $attrs);
307 The relationship name can be arbitrary, but must be unique for each
308 relationship attached to this result source. 'related_source' should
309 be the name with which the related result source was registered with
310 the current schema. For example:
312 $schema->source('Book')->add_relationship('reviews', 'Review', {
313 'foreign.book_id' => 'self.id',
316 The condition C<$cond> needs to be an L<SQL::Abstract>-style
317 representation of the join between the tables. For example, if you're
318 creating a rel from Author to Book,
320 { 'foreign.author_id' => 'self.id' }
322 will result in the JOIN clause
324 author me JOIN book foreign ON foreign.author_id = me.id
326 You can specify as many foreign => self mappings as necessary.
328 Valid attributes are as follows:
334 Explicitly specifies the type of join to use in the relationship. Any
335 SQL join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in
336 the SQL command immediately before C<JOIN>.
340 An arrayref containing a list of accessors in the foreign class to proxy in
341 the main class. If, for example, you do the following:
343 CD->might_have(liner_notes => 'LinerNotes', undef, {
344 proxy => [ qw/notes/ ],
347 Then, assuming LinerNotes has an accessor named notes, you can do:
349 my $cd = CD->find(1);
350 # set notes -- LinerNotes object is created if it doesn't exist
351 $cd->notes('Notes go here');
355 Specifies the type of accessor that should be created for the
356 relationship. Valid values are C<single> (for when there is only a single
357 related object), C<multi> (when there can be many), and C<filter> (for
358 when there is a single related object, but you also want the relationship
359 accessor to double as a column accessor). For C<multi> accessors, an
360 add_to_* method is also created, which calls C<create_related> for the
367 sub add_relationship {
368 my ($self, $rel, $f_source_name, $cond, $attrs) = @_;
369 $self->throw_exception("Can't create relationship without join condition")
373 my %rels = %{ $self->_relationships };
374 $rels{$rel} = { class => $f_source_name,
375 source => $f_source_name,
378 $self->_relationships(\%rels);
382 # XXX disabled. doesn't work properly currently. skip in tests.
384 my $f_source = $self->schema->source($f_source_name);
386 eval "require $f_source_name;";
388 die $@ unless $@ =~ /Can't locate/;
390 $f_source = $f_source_name->result_source;
391 #my $s_class = ref($self->schema);
392 #$f_source_name =~ m/^${s_class}::(.*)$/;
393 #$self->schema->register_class(($1 || $f_source_name), $f_source_name);
394 #$f_source = $self->schema->source($f_source_name);
396 return unless $f_source; # Can't test rel without f_source
398 eval { $self->resolve_join($rel, 'me') };
400 if ($@) { # If the resolve failed, back out and re-throw the error
401 delete $rels{$rel}; #
402 $self->_relationships(\%rels);
403 $self->throw_exception("Error creating relationship $rel: $@");
410 Returns all relationship names for this source.
415 return keys %{shift->_relationships};
418 =head2 relationship_info
422 =item Arguments: $relname
426 Returns a hash of relationship information for the specified relationship
431 sub relationship_info {
432 my ($self, $rel) = @_;
433 return $self->_relationships->{$rel};
436 =head2 has_relationship
440 =item Arguments: $rel
444 Returns true if the source has a relationship of this name, false otherwise.
448 sub has_relationship {
449 my ($self, $rel) = @_;
450 return exists $self->_relationships->{$rel};
457 =item Arguments: $relation
461 Returns the join structure required for the related result source.
466 my ($self, $join, $alias, $seen) = @_;
468 if (ref $join eq 'ARRAY') {
469 return map { $self->resolve_join($_, $alias, $seen) } @$join;
470 } elsif (ref $join eq 'HASH') {
473 my $as = ($seen->{$_} ? $_.'_'.($seen->{$_}+1) : $_);
474 ($self->resolve_join($_, $alias, $seen),
475 $self->related_source($_)->resolve_join($join->{$_}, $as, $seen));
477 } elsif (ref $join) {
478 $self->throw_exception("No idea how to resolve join reftype ".ref $join);
480 my $count = ++$seen->{$join};
481 #use Data::Dumper; warn Dumper($seen);
482 my $as = ($count > 1 ? "${join}_${count}" : $join);
483 my $rel_info = $self->relationship_info($join);
484 $self->throw_exception("No such relationship ${join}") unless $rel_info;
485 my $type = $rel_info->{attrs}{join_type} || '';
486 return [ { $as => $self->related_source($join)->from,
487 -join_type => $type },
488 $self->resolve_condition($rel_info->{cond}, $as, $alias) ];
492 =head2 resolve_condition
496 =item Arguments: $cond, $as, $alias|$object
500 Resolves the passed condition to a concrete query fragment. If given an alias,
501 returns a join condition; if given an object, inverts that object to produce
502 a related conditional from that object.
506 sub resolve_condition {
507 my ($self, $cond, $as, $for) = @_;
509 if (ref $cond eq 'HASH') {
511 while (my ($k, $v) = each %{$cond}) {
512 # XXX should probably check these are valid columns
513 $k =~ s/^foreign\.// ||
514 $self->throw_exception("Invalid rel cond key ${k}");
516 $self->throw_exception("Invalid rel cond val ${v}");
517 if (ref $for) { # Object
518 #warn "$self $k $for $v";
519 $ret{$k} = $for->get_column($v);
521 } elsif (ref $as) { # reverse object
522 $ret{$v} = $as->get_column($k);
524 $ret{"${as}.${k}"} = "${for}.${v}";
528 } elsif (ref $cond eq 'ARRAY') {
529 return [ map { $self->resolve_condition($_, $as, $for) } @$cond ];
531 die("Can't handle this yet :(");
535 =head2 resolve_prefetch
539 =item Arguments: hashref/arrayref/scalar
543 Accepts one or more relationships for the current source and returns an
544 array of column names for each of those relationships. Column names are
545 prefixed relative to the current source, in accordance with where they appear
546 in the supplied relationships. Examples:
548 my $source = $schema->resultset('Tag')->source;
549 @columns = $source->resolve_prefetch( { cd => 'artist' } );
557 # 'cd.artist.artistid',
561 @columns = $source->resolve_prefetch( qw[/ cd /] );
571 $source = $schema->resultset('CD')->source;
572 @columns = $source->resolve_prefetch( qw[/ artist producer /] );
578 # 'producer.producerid',
584 sub resolve_prefetch {
585 my ($self, $pre, $alias, $seen, $order, $collapse) = @_;
587 #$alias ||= $self->name;
588 #warn $alias, Dumper $pre;
589 if( ref $pre eq 'ARRAY' ) {
591 map { $self->resolve_prefetch( $_, $alias, $seen, $order, $collapse ) }
594 elsif( ref $pre eq 'HASH' ) {
597 $self->resolve_prefetch($_, $alias, $seen, $order, $collapse),
598 $self->related_source($_)->resolve_prefetch(
599 $pre->{$_}, "${alias}.$_", $seen, $order, $collapse)
605 $self->throw_exception(
606 "don't know how to resolve prefetch reftype ".ref($pre));
609 my $count = ++$seen->{$pre};
610 my $as = ($count > 1 ? "${pre}_${count}" : $pre);
611 my $rel_info = $self->relationship_info( $pre );
612 $self->throw_exception( $self->name . " has no such relationship '$pre'" )
614 my $as_prefix = ($alias =~ /^.*?\.(.+)$/ ? $1.'.' : '');
615 my $rel_source = $self->related_source($pre);
617 if (exists $rel_info->{attrs}{accessor}
618 && $rel_info->{attrs}{accessor} eq 'multi') {
619 $self->throw_exception(
620 "Can't prefetch has_many ${pre} (join cond too complex)")
621 unless ref($rel_info->{cond}) eq 'HASH';
622 my @key = map { (/^foreign\.(.+)$/ ? ($1) : ()); }
623 keys %{$rel_info->{cond}};
624 $collapse->{"${as_prefix}${pre}"} = \@key;
625 my @ord = (ref($rel_info->{attrs}{order_by}) eq 'ARRAY'
626 ? @{$rel_info->{attrs}{order_by}}
627 : (defined $rel_info->{attrs}{order_by}
628 ? ($rel_info->{attrs}{order_by})
630 push(@$order, map { "${as}.$_" } (@key, @ord));
633 return map { [ "${as}.$_", "${as_prefix}${pre}.$_", ] }
634 $rel_source->columns;
635 #warn $alias, Dumper (\@ret);
640 =head2 related_source
644 =item Arguments: $relname
648 Returns the result source object for the given relationship.
653 my ($self, $rel) = @_;
654 if( !$self->has_relationship( $rel ) ) {
655 $self->throw_exception("No such relationship '$rel'");
657 return $self->schema->source($self->relationship_info($rel)->{source});
664 =item Arguments: $relname
668 Returns the class name for objects in the given relationship.
673 my ($self, $rel) = @_;
674 if( !$self->has_relationship( $rel ) ) {
675 $self->throw_exception("No such relationship '$rel'");
677 return $self->schema->class($self->relationship_info($rel)->{source});
682 Returns a resultset for the given source. This will initially be created
685 $self->resultset_class->new($self, $self->resultset_attributes)
687 but is cached from then on unless resultset_class changes.
689 =head2 resultset_class
691 Set the class of the resultset, this is useful if you want to create your
692 own resultset methods. Create your own class derived from
693 L<DBIx::Class::ResultSet>, and set it here.
695 =head2 resultset_attributes
697 Specify here any attributes you wish to pass to your specialised resultset.
703 $self->throw_exception(
704 'resultset does not take any arguments. If you want another resultset, '.
705 'call it on the schema instead.'
707 return $self->{_resultset}
708 if ref $self->{_resultset} eq $self->resultset_class;
709 return $self->{_resultset} = $self->resultset_class->new(
710 $self, $self->{resultset_attributes}
714 =head2 throw_exception
716 See L<DBIx::Class::Schema/"throw_exception">.
720 sub throw_exception {
722 if (defined $self->schema) {
723 $self->schema->throw_exception(@_);
731 Matt S. Trout <mst@shadowcatsystems.co.uk>
735 You may distribute this code under the same terms as Perl itself.