use base qw/DBIx::Class/;
+use Scalar::Util qw/weaken blessed/;
+use Try::Tiny;
+use namespace::clean;
+
=head1 NAME
DBIx::Class::Relationship::Base - Inter-table relationships
__PACKAGE__->add_relationship('relname', 'Foreign::Class', $cond, $attrs);
+=head3 condition
+
The condition needs to be an L<SQL::Abstract>-style representation of the
join between the tables. When resolving the condition for use in a C<JOIN>,
keys using the pseudo-table C<foreign> are resolved to mean "the Table on the
To add an C<OR>ed condition, use an arrayref of hashrefs. See the
L<SQL::Abstract> documentation for more details.
-Valid attributes are as follows:
+=head3 attributes
+
+The L<standard ResultSet attributes|DBIx::Class::ResultSet/ATTRIBUTES> may
+be used as relationship attributes. In particular, the 'where' attribute is
+useful for filtering relationships:
+
+ __PACKAGE__->has_many( 'valid_users', 'MyApp::Schema::User',
+ { 'foreign.user_id' => 'self.user_id' },
+ { where => { valid => 1 } }
+ );
+
+The following attributes are also valid:
=over 4
An arrayref containing a list of accessors in the foreign class to create in
the main class. If, for example, you do the following:
-
+
MyDB::Schema::CD->might_have(liner_notes => 'MyDB::Schema::LinerNotes',
undef, {
proxy => [ qw/notes/ ],
});
-
+
Then, assuming MyDB::Schema::LinerNotes has an accessor named notes, you can do:
my $cd = MyDB::Schema::CD->find(1);
$cd->notes('Notes go here'); # set notes -- LinerNotes object is
# created if it doesn't exist
-
+
=item accessor
Specifies the type of accessor that should be created for the relationship.
a column accessor). For C<multi> accessors, an add_to_* method is also
created, which calls C<create_related> for the relationship.
+=item is_foreign_key_constraint
+
+If you are using L<SQL::Translator> to create SQL for you and you find that it
+is creating constraints where it shouldn't, or not creating them where it
+should, set this attribute to a true or false value to override the detection
+of when to create constraints.
+
+=item cascade_copy
+
+If C<cascade_copy> is true on a C<has_many> relationship for an
+object, then when you copy the object all the related objects will
+be copied too. To turn this behaviour off, pass C<< cascade_copy => 0 >>
+in the C<$attr> hashref.
+
+The behaviour defaults to C<< cascade_copy => 1 >> for C<has_many>
+relationships.
+
+=item cascade_delete
+
+By default, DBIx::Class cascades deletes across C<has_many>,
+C<has_one> and C<might_have> relationships. You can disable this
+behaviour on a per-relationship basis by supplying
+C<< cascade_delete => 0 >> in the relationship attributes.
+
+The cascaded operations are performed after the requested delete,
+so if your database has a constraint on the relationship, it will
+have deleted/updated the related records or raised an exception
+before DBIx::Class gets to perform the cascaded operation.
+
+=item cascade_update
+
+By default, DBIx::Class cascades updates across C<has_one> and
+C<might_have> relationships. You can disable this behaviour on a
+per-relationship basis by supplying C<< cascade_update => 0 >> in
+the relationship attributes.
+
+This is not a RDMS style cascade update - it purely means that when
+an object has update called on it, all the related objects also
+have update called. It will not change foreign keys automatically -
+you must arrange to do this yourself.
+
+=item on_delete / on_update
+
+If you are using L<SQL::Translator> to create SQL for you, you can use these
+attributes to explicitly set the desired C<ON DELETE> or C<ON UPDATE> constraint
+type. If not supplied the SQLT parser will attempt to infer the constraint type by
+interrogating the attributes of the B<opposite> relationship. For any 'multi'
+relationship with C<< cascade_delete => 1 >>, the corresponding belongs_to
+relationship will be created with an C<ON DELETE CASCADE> constraint. For any
+relationship bearing C<< cascade_copy => 1 >> the resulting belongs_to constraint
+will be C<ON UPDATE CASCADE>. If you wish to disable this autodetection, and just
+use the RDBMS' default constraint type, pass C<< on_delete => undef >> or
+C<< on_delete => '' >>, and the same for C<on_update> respectively.
+
+=item is_deferrable
+
+Tells L<SQL::Translator> that the foreign key constraint it creates should be
+deferrable. In other words, the user may request that the constraint be ignored
+until the end of the transaction. Currently, only the PostgreSQL producer
+actually supports this.
+
+=item add_fk_index
+
+Tells L<SQL::Translator> to add an index for this constraint. Can also be
+specified globally in the args to L<DBIx::Class::Schema/deploy> or
+L<DBIx::Class::Schema/create_ddl_dir>. Default is on, set to 0 to disable.
+
=back
=head2 register_relationship
$self->throw_exception("Can't call *_related as class methods")
unless ref $self;
my $rel = shift;
- my $rel_obj = $self->relationship_info($rel);
+ my $rel_info = $self->relationship_info($rel);
$self->throw_exception( "No such relationship ${rel}" )
- unless $rel_obj;
-
+ unless $rel_info;
+
return $self->{related_resultsets}{$rel} ||= do {
my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
- $attrs = { %{$rel_obj->{attrs} || {}}, %$attrs };
+ $attrs = { %{$rel_info->{attrs} || {}}, %$attrs };
$self->throw_exception( "Invalid query: @_" )
if (@_ > 1 && (@_ % 2 == 1));
my $query = ((@_ > 1) ? {@_} : shift);
- my $cond = $self->result_source->resolve_condition(
- $rel_obj->{cond}, $rel, $self
- );
+ my $source = $self->result_source;
+
+ # condition resolution may fail if an incomplete master-object prefetch
+ # is encountered - that is ok during prefetch construction (not yet in_storage)
+ my $cond = try {
+ $source->_resolve_condition( $rel_info->{cond}, $rel, $self )
+ }
+ catch {
+ if ($self->in_storage) {
+ $self->throw_exception ($_);
+ }
+
+ $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION; # RV
+ };
+
+ if ($cond eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
+ my $reverse = $source->reverse_relationship_info($rel);
+ foreach my $rev_rel (keys %$reverse) {
+ if ($reverse->{$rev_rel}{attrs}{accessor} && $reverse->{$rev_rel}{attrs}{accessor} eq 'multi') {
+ $attrs->{related_objects}{$rev_rel} = [ $self ];
+ weaken $attrs->{related_object}{$rev_rel}[0];
+ } else {
+ $attrs->{related_objects}{$rev_rel} = $self;
+ weaken $attrs->{related_object}{$rev_rel};
+ }
+ }
+ }
if (ref $cond eq 'ARRAY') {
- $cond = [ map { my $hash;
- foreach my $key (keys %$_) {
- my $newkey = $key =~ /\./ ? "me.$key" : $key;
- $hash->{$newkey} = $_->{$key};
- }; $hash } @$cond ];
- } else {
+ $cond = [ map {
+ if (ref $_ eq 'HASH') {
+ my $hash;
+ foreach my $key (keys %$_) {
+ my $newkey = $key !~ /\./ ? "me.$key" : $key;
+ $hash->{$newkey} = $_->{$key};
+ }
+ $hash;
+ } else {
+ $_;
+ }
+ } @$cond ];
+ } elsif (ref $cond eq 'HASH') {
foreach my $key (grep { ! /\./ } keys %$cond) {
$cond->{"me.$key"} = delete $cond->{$key};
}
( $objects_rs ) = $rs->search_related_rs('relname', $cond, $attrs);
-This method works exactly the same as search_related, except that
-it garauntees a restultset, even in list context.
+This method works exactly the same as search_related, except that
+it guarantees a resultset, even in list context.
=cut
my $new_obj = $obj->new_related('relname', \%col_data);
Create a new item of the related foreign class. If called on a
-L<DBIx::Class::Manual::Glossary/"Row"> object, it will magically set any
-primary key values into foreign key columns for you. The newly created item
-will not be saved into your storage until you call L<DBIx::Class::Row/insert>
+L<Row|DBIx::Class::Manual::Glossary/"Row"> object, it will magically
+set any foreign key columns of the new object to the related primary
+key columns of the source object for you. The newly created item will
+not be saved into your storage until you call L<DBIx::Class::Row/insert>
on it.
=cut
sub find_or_new_related {
my $self = shift;
- return $self->find_related(@_) || $self->new_related(@_);
+ my $obj = $self->find_related(@_);
+ return defined $obj ? $obj : $self->new_related(@_);
}
=head2 find_or_create_related
=head2 set_from_related
$book->set_from_related('author', $author_obj);
+ $book->author($author_obj); ## same thing
Set column values on the current object, using related values from the given
related object. This is used to associate previously separate objects, for
example, to set the correct author for a book, find the Author object, then
call set_from_related on the book.
+This is called internally when you pass existing objects as values to
+L<DBIx::Class::ResultSet/create>, or pass an object to a belongs_to accessor.
+
The columns are only set in the local copy of the object, call L</update> to
set them in the storage.
sub set_from_related {
my ($self, $rel, $f_obj) = @_;
- my $rel_obj = $self->relationship_info($rel);
- $self->throw_exception( "No such relationship ${rel}" ) unless $rel_obj;
- my $cond = $rel_obj->{cond};
+ my $rel_info = $self->relationship_info($rel);
+ $self->throw_exception( "No such relationship ${rel}" ) unless $rel_info;
+ my $cond = $rel_info->{cond};
$self->throw_exception(
"set_from_related can only handle a hash condition; the ".
"condition for $rel is of type ".
(ref $cond ? ref $cond : 'plain scalar')
) unless ref $cond eq 'HASH';
if (defined $f_obj) {
- my $f_class = $self->result_source->schema->class($rel_obj->{class});
+ my $f_class = $rel_info->{class};
$self->throw_exception( "Object $f_obj isn't a ".$f_class )
- unless $f_obj->isa($f_class);
+ unless blessed $f_obj and $f_obj->isa($f_class);
}
$self->set_columns(
- $self->result_source->resolve_condition(
- $rel_obj->{cond}, $f_obj, $rel));
+ $self->result_source->_resolve_condition(
+ $rel_info->{cond}, $f_obj, $rel));
return 1;
}
return $obj;
}
-1;
+=head2 add_to_$rel
+
+B<Currently only available for C<has_many>, C<many-to-many> and 'multi' type
+relationships.>
+
+=over 4
+
+=item Arguments: ($foreign_vals | $obj), $link_vals?
+
+=back
+
+ my $role = $schema->resultset('Role')->find(1);
+ $actor->add_to_roles($role);
+ # creates a My::DBIC::Schema::ActorRoles linking table row object
+
+ $actor->add_to_roles({ name => 'lead' }, { salary => 15_000_000 });
+ # creates a new My::DBIC::Schema::Role row object and the linking table
+ # object with an extra column in the link
+
+Adds a linking table object for C<$obj> or C<$foreign_vals>. If the first
+argument is a hash reference, the related object is created first with the
+column values in the hash. If an object reference is given, just the linking
+table object is created. In either case, any additional column values for the
+linking table object can be specified in C<$link_vals>.
+
+=head2 set_$rel
+
+B<Currently only available for C<many-to-many> relationships.>
+
+=over 4
+
+=item Arguments: (\@hashrefs | \@objs), $link_vals?
+
+=back
+
+ my $actor = $schema->resultset('Actor')->find(1);
+ my @roles = $schema->resultset('Role')->search({ role =>
+ { '-in' => ['Fred', 'Barney'] } } );
+
+ $actor->set_roles(\@roles);
+ # Replaces all of $actor's previous roles with the two named
+
+ $actor->set_roles(\@roles, { salary => 15_000_000 });
+ # Sets a column in the link table for all roles
+
+
+Replace all the related objects with the given reference to a list of
+objects. This does a C<delete> B<on the link table resultset> to remove the
+association between the current object and all related objects, then calls
+C<add_to_$rel> repeatedly to link all the new objects.
+
+Note that this means that this method will B<not> delete any objects in the
+table on the right side of the relation, merely that it will delete the link
+between them.
+
+Due to a mistake in the original implementation of this method, it will also
+accept a list of objects or hash references. This is B<deprecated> and will be
+removed in a future version.
+
+=head2 remove_from_$rel
+
+B<Currently only available for C<many-to-many> relationships.>
+
+=over 4
+
+=item Arguments: $obj
+
+=back
+
+ my $role = $schema->resultset('Role')->find(1);
+ $actor->remove_from_roles($role);
+ # removes $role's My::DBIC::Schema::ActorRoles linking table row object
+
+Removes the link between the current object and the related object. Note that
+the related object itself won't be deleted unless you call ->delete() on
+it. This method just removes the link between the two objects.
=head1 AUTHORS
=cut
+1;
projects / dbsrgits/DBIx-Class.git / blobdiff