1 package DBIx::Class::Relationship::Base;
6 use base qw/DBIx::Class/;
8 __PACKAGE__->mk_classdata('_relationships', { } );
12 DBIx::Class::Relationship::Base - Inter-table relationships
18 This class handles relationships between the tables in your database
19 model. It allows your to set up relationships, and to perform joins
24 =head2 add_relationship
26 __PACKAGE__->add_relationship('relname', 'Foreign::Class', $cond, $attrs);
28 The condition needs to be an SQL::Abstract-style representation of the
29 join between the tables. For example, if you're creating a rel from Foo to Bar,
31 { 'foreign.foo_id' => 'self.id' }
33 will result in the JOIN clause
35 foo me JOIN bar bar ON bar.foo_id = me.id
37 You can specify as many foreign => self mappings as necessary.
39 Valid attributes are as follows:
45 Explicitly specifies the type of join to use in the relationship. Any SQL
46 join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in the SQL
47 command immediately before C<JOIN>.
51 An arrayref containing a list of accessors in the foreign class to proxy in
52 the main class. If, for example, you do the following:
54 __PACKAGE__->might_have(bar => 'Bar', undef, { proxy => qw[/ margle /] });
56 Then, assuming Bar has an accessor named margle, you can do:
58 my $obj = Foo->find(1);
59 $obj->margle(10); # set margle; Bar object is created if it doesn't exist
63 Specifies the type of accessor that should be created for the relationship.
64 Valid values are C<single> (for when there is only a single related object),
65 C<multi> (when there can be many), and C<filter> (for when there is a single
66 related object, but you also want the relationship accessor to double as
67 a column accessor). For C<multi> accessors, an add_to_* method is also
68 created, which calls C<create_related> for the relationship.
74 sub add_relationship {
75 shift->result_source->add_relationship(@_);
79 shift->result_source->relationships(@_);
82 sub relationship_info {
83 shift->result_source->relationship_info(@_);
87 my ($class, $join, $alias) = @_;
88 if (ref $join eq 'ARRAY') {
89 return map { $class->_resolve_join($_, $alias) } @$join;
90 } elsif (ref $join eq 'HASH') {
91 return map { $class->_resolve_join($_, $alias),
92 $class->relationship_info($_)->{class}->_resolve_join($join->{$_}, $_) }
95 $class->throw("No idea how to resolve join reftype ".ref $join);
97 my $rel_obj = $class->relationship_info($join);
98 #use Data::Dumper; warn Dumper($class->result_source) unless $rel_obj;
99 $class->throw("No such relationship ${join}") unless $rel_obj;
100 my $j_class = $rel_obj->{class};
101 my %join = (_action => 'join',
102 _aliases => { 'self' => $alias, 'foreign' => $join },
103 _classes => { $alias => $class, $join => $j_class });
104 my $j_cond = $j_class->resolve_condition($rel_obj->{cond}, \%join);
105 return [ { $join => $j_class->_table_name,
106 -join_type => $rel_obj->{attrs}{join_type} || '' }, $j_cond ];
110 sub resolve_condition {
111 my ($self, $cond, $attrs) = @_;
112 if (ref $cond eq 'HASH') {
114 foreach my $key (keys %$cond) {
115 my $val = $cond->{$key};
117 $self->throw("Can't handle this yet :(");
119 $ret{$self->_cond_key($attrs => $key)}
120 = $self->_cond_value($attrs => $key => $val);
125 $self->throw("Can't handle this yet :(");
130 my ($self, $attrs, $key, $alias) = @_;
131 my $action = $attrs->{_action} || '';
132 if ($action eq 'convert') {
133 unless ($key =~ s/^foreign\.//) {
134 $self->throw("Unable to convert relationship to WHERE clause: invalid key ${key}");
136 if (defined (my $alias = $attrs->{_aliases}{foreign})) {
137 return "${alias}.${key}";
141 } elsif ($action eq 'join') {
142 return $key unless $key =~ /\./;
143 my ($type, $field) = split(/\./, $key);
144 if (my $alias = $attrs->{_aliases}{$type}) {
145 my $class = $attrs->{_classes}{$alias};
146 $self->throw("Unknown column $field on $class as $alias")
147 unless $class->has_column($field);
148 return join('.', $alias, $field);
150 $self->throw( "Unable to resolve type ${type}: only have aliases for ".
151 join(', ', keys %{$attrs->{_aliases} || {}}) );
154 return $self->next::method($attrs, $key);
158 my ($self, $attrs, $key, $value) = @_;
159 my $action = $attrs->{_action} || '';
160 if ($action eq 'convert') {
161 unless ($value =~ s/^self\.//) {
162 $self->throw( "Unable to convert relationship to WHERE clause: invalid value ${value}" );
164 unless ($self->has_column($value)) {
165 $self->throw( "Unable to convert relationship to WHERE clause: no such accessor ${value}" );
167 return $self->get_column($value);
168 } elsif ($action eq 'join') {
169 return $key unless $key =~ /\./;
170 my ($type, $field) = split(/\./, $value);
171 if (my $alias = $attrs->{_aliases}{$type}) {
172 my $class = $attrs->{_classes}{$alias};
173 $self->throw("Unknown column $field on $class as $alias")
174 unless $class->has_column($field);
175 return join('.', $alias, $field);
177 $self->throw( "Unable to resolve type ${type}: only have aliases for ".
178 join(', ', keys %{$attrs->{_aliases} || {}}) );
182 return $self->next::method($attrs, $key, $value)
185 =head2 search_related
187 My::Table->search_related('relname', $cond, $attrs);
195 if (@_ > 1 && ref $_[$#_] eq 'HASH') {
196 $attrs = { %{ pop(@_) } };
198 my $rel_obj = $self->relationship_info($rel);
199 $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
200 $attrs = { %{$rel_obj->{attrs} || {}}, %{$attrs || {}} };
202 $self->throw( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1));
203 my $query = ((@_ > 1) ? {@_} : shift);
205 $attrs->{_action} = 'convert'; # shouldn't we resolve the cond to something
206 # to merge into the AST really?
207 my ($cond) = $self->resolve_condition($rel_obj->{cond}, $attrs);
208 $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
209 #use Data::Dumper; warn Dumper($query);
210 #warn $rel_obj->{class}." $meth $cond ".join(', ', @{$attrs->{bind}||[]});
211 delete $attrs->{_action};
212 return $self->result_source->schema->resultset($rel_obj->{class}
213 )->search($query, $attrs);
218 My::Table->count_related('relname', $cond, $attrs);
224 return $self->search_related(@_)->count;
227 =head2 create_related
229 My::Table->create_related('relname', \%col_data);
236 return $class->search_related($rel)->create(@_);
241 My::Table->new_related('relname', \%col_data);
246 my ($self, $rel, $values, $attrs) = @_;
247 return $self->search_related($rel)->new($values, $attrs);
252 My::Table->find_related('relname', @pri_vals | \%pri_vals);
259 return $self->search_related($rel)->find(@_);
262 =head2 find_or_create_related
264 My::Table->find_or_create_related('relname', \%col_data);
268 sub find_or_create_related {
270 return $self->find_related(@_) || $self->create_related(@_);
273 =head2 set_from_related
275 My::Table->set_from_related('relname', $rel_obj);
279 sub set_from_related {
280 my ($self, $rel, $f_obj) = @_;
281 my $rel_obj = $self->relationship_info($rel);
282 $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
283 my $cond = $rel_obj->{cond};
284 $self->throw( "set_from_related can only handle a hash condition; the "
285 ."condition for $rel is of type ".(ref $cond ? ref $cond : 'plain scalar'))
286 unless ref $cond eq 'HASH';
287 my $f_class = $self->result_source->schema->class($rel_obj->{class});
288 $self->throw( "Object $f_obj isn't a ".$f_class )
289 unless $f_obj->isa($f_class);
290 foreach my $key (keys %$cond) {
291 next if ref $cond->{$key}; # Skip literals and complex conditions
292 $self->throw("set_from_related can't handle $key as key")
293 unless $key =~ m/^foreign\.([^\.]+)$/;
294 my $val = $f_obj->get_column($1);
295 $self->throw("set_from_related can't handle ".$cond->{$key}." as value")
296 unless $cond->{$key} =~ m/^self\.([^\.]+)$/;
297 $self->set_column($1 => $val);
302 =head2 update_from_related
304 My::Table->update_from_related('relname', $rel_obj);
308 sub update_from_related {
310 $self->set_from_related(@_);
314 =head2 delete_related
316 My::Table->delete_related('relname', $cond, $attrs);
322 return $self->search_related(@_)->delete;
329 Matt S. Trout <mst@shadowcatsystems.co.uk>
333 You may distribute this code under the same terms as Perl itself.