1 package DBIx::Class::Schema::Loader::RelBuilder;
6 use Carp::Clan qw/^DBIx::Class/;
7 use Lingua::EN::Inflect::Number ();
8 use Lingua::EN::Inflect::Phrase ();
10 our $VERSION = '0.05003';
14 DBIx::Class::Schema::Loader::RelBuilder - Builds relationships for DBIx::Class::Schema::Loader
18 See L<DBIx::Class::Schema::Loader>
22 This class builds relationships for L<DBIx::Class::Schema::Loader>. This
23 is module is not (yet) for external use.
29 Arguments: schema_class (scalar), inflect_plural, inflect_singular
31 C<$schema_class> should be a schema class name, where the source
32 classes have already been set up and registered. Column info, primary
33 key, and unique constraints will be drawn from this schema for all
34 of the existing source monikers.
36 Options inflect_plural and inflect_singular are optional, and are better documented
37 in L<DBIx::Class::Schema::Loader::Base>.
41 Arguments: local_moniker (scalar), fk_info (arrayref)
43 This generates the code for the relationships of a given table.
45 C<local_moniker> is the moniker name of the table which had the REFERENCES
46 statements. The fk_info arrayref's contents should take the form:
50 local_columns => [ 'col2', 'col3' ],
51 remote_columns => [ 'col5', 'col7' ],
52 remote_moniker => 'AnotherTableMoniker',
55 local_columns => [ 'col1', 'col4' ],
56 remote_columns => [ 'col1', 'col2' ],
57 remote_moniker => 'YetAnotherTableMoniker',
62 This method will return the generated relationships as a hashref keyed on the
63 class names. The values are arrayrefs of hashes containing method name and
67 'Some::Source::Class' => [
68 { method => 'belongs_to', arguments => [ 'col1', 'Another::Source::Class' ],
69 { method => 'has_many', arguments => [ 'anothers', 'Yet::Another::Source::Class', 'col15' ],
71 'Another::Source::Class' => [
81 my ( $class, $schema, $inflect_pl, $inflect_singular, $rel_attrs ) = @_;
85 inflect_plural => $inflect_pl,
86 inflect_singular => $inflect_singular,
87 relationship_attrs => $rel_attrs,
90 # validate the relationship_attrs arg
91 if( defined $self->{relationship_attrs} ) {
92 ref($self->{relationship_attrs}) eq 'HASH'
93 or croak "relationship_attrs must be a hashref";
96 return bless $self => $class;
100 # pluralize a relationship name
101 sub _inflect_plural {
102 my ($self, $relname, $method) = @_;
104 return '' if !defined $relname || $relname eq '';
106 if( ref $self->{inflect_plural} eq 'HASH' ) {
107 return $self->{inflect_plural}->{$relname}
108 if exists $self->{inflect_plural}->{$relname};
110 elsif( ref $self->{inflect_plural} eq 'CODE' ) {
111 my $inflected = $self->{inflect_plural}->($relname);
112 return $inflected if $inflected;
115 $method ||= '_to_PL';
117 return $self->$method($relname);
120 # Singularize a relationship name
121 sub _inflect_singular {
122 my ($self, $relname) = @_;
124 return '' if !defined $relname || $relname eq '';
126 if( ref $self->{inflect_singular} eq 'HASH' ) {
127 return $self->{inflect_singular}->{$relname}
128 if exists $self->{inflect_singular}->{$relname};
130 elsif( ref $self->{inflect_singular} eq 'CODE' ) {
131 my $inflected = $self->{inflect_singular}->($relname);
132 return $inflected if $inflected;
135 return $self->_to_S($relname);
139 my ($self, $name) = @_;
142 my $plural = Lingua::EN::Inflect::Phrase::to_PL($name);
149 my ($self, $name) = @_;
151 return Lingua::EN::Inflect::Number::to_PL($name);
155 my ($self, $name) = @_;
158 my $singular = Lingua::EN::Inflect::Phrase::to_S($name);
159 $singular =~ s/ /_/g;
164 sub _default_relationship_attrs { +{
174 on_delete => 'CASCADE',
175 on_update => 'CASCADE',
179 # accessor for options to be passed to each generated relationship
180 # type. take single argument, the relationship type name, and returns
181 # either a hashref (if some options are set), or nothing
182 sub _relationship_attrs {
183 my ( $self, $reltype ) = @_;
184 my $r = $self->{relationship_attrs};
187 %{ $self->_default_relationship_attrs->{$reltype} || {} },
191 if( my $specific = $r->{$reltype} ) {
192 while( my ($k,$v) = each %$specific ) {
202 return unless @$a == @$b;
204 for (my $i = 0; $i < @$a; $i++) {
205 return unless $a->[$i] eq $b->[$i];
211 my ($self, $local_moniker, $local_cols) = @_;
213 # get our base set of attrs from _relationship_attrs, if present
214 my $attrs = $self->_relationship_attrs('belongs_to') || {};
216 # If the referring column is nullable, make 'belongs_to' an
217 # outer join, unless explicitly set by relationship_attrs
218 my $nullable = grep { $self->{schema}->source($local_moniker)->column_info($_)->{is_nullable} } @$local_cols;
219 $attrs->{join_type} = 'LEFT' if $nullable && !defined $attrs->{join_type};
224 sub _remote_relname {
225 my ($self, $remote_table, $cond) = @_;
228 # for single-column case, set the remote relname to the column
229 # name, to make filter accessors work, but strip trailing _id
230 if(scalar keys %{$cond} == 1) {
231 my ($col) = values %{$cond};
234 $remote_relname = $self->_inflect_singular($col);
237 $remote_relname = $self->_inflect_singular(lc $remote_table);
240 return $remote_relname;
244 my ($self, $local_moniker, $rels, $uniqs) = @_;
248 my $local_class = $self->{schema}->class($local_moniker);
251 foreach my $rel (@$rels) {
252 next if !$rel->{remote_source};
253 $counters{$rel->{remote_source}}++;
256 foreach my $rel (@$rels) {
257 my $remote_moniker = $rel->{remote_source}
260 my $remote_class = $self->{schema}->class($remote_moniker);
261 my $remote_obj = $self->{schema}->source($remote_moniker);
262 my $remote_cols = $rel->{remote_columns} || [ $remote_obj->primary_columns ];
264 my $local_cols = $rel->{local_columns};
266 if($#$local_cols != $#$remote_cols) {
267 croak "Column count mismatch: $local_moniker (@$local_cols) "
268 . "$remote_moniker (@$remote_cols)";
272 foreach my $i (0 .. $#$local_cols) {
273 $cond{$remote_cols->[$i]} = $local_cols->[$i];
276 my ( $local_relname, $remote_relname, $remote_method ) =
277 $self->_relnames_and_method( $local_moniker, $rel, \%cond, $uniqs, \%counters );
279 push(@{$all_code->{$local_class}},
280 { method => 'belongs_to',
281 args => [ $remote_relname,
284 $self->_remote_attrs($local_moniker, $local_cols),
289 my %rev_cond = reverse %cond;
290 for (keys %rev_cond) {
291 $rev_cond{"foreign.$_"} = "self.".$rev_cond{$_};
292 delete $rev_cond{$_};
295 push(@{$all_code->{$remote_class}},
296 { method => $remote_method,
297 args => [ $local_relname,
300 $self->_relationship_attrs($remote_method),
309 sub _relnames_and_method {
310 my ( $self, $local_moniker, $rel, $cond, $uniqs, $counters ) = @_;
312 my $remote_moniker = $rel->{remote_source};
313 my $remote_obj = $self->{schema}->source( $remote_moniker );
314 my $remote_class = $self->{schema}->class( $remote_moniker );
315 my $remote_relname = lc $self->_remote_relname( $remote_obj->from, $cond);
317 my $local_cols = $rel->{local_columns};
318 my $local_table = $self->{schema}->source($local_moniker)->from;
320 # If more than one rel between this pair of tables, use the local
321 # col names to distinguish
322 my ($local_relname, $old_local_relname, $local_relname_uninflected, $old_local_relname_uninflected);
323 if ( $counters->{$remote_moniker} > 1) {
324 my $colnames = lc(q{_} . join(q{_}, @$local_cols));
325 $remote_relname .= $colnames if keys %$cond > 1;
327 $local_relname = lc($local_table) . $colnames;
328 $local_relname =~ s/_id$//;
330 $local_relname_uninflected = $local_relname;
331 $local_relname = $self->_inflect_plural( $local_relname );
333 $old_local_relname_uninflected = lc($local_table) . $colnames;
334 $old_local_relname = $self->_inflect_plural( lc($local_table) . $colnames, '_old_to_PL' );
337 $local_relname_uninflected = lc $local_table;
338 $local_relname = $self->_inflect_plural(lc $local_table);
340 $old_local_relname_uninflected = lc $local_table;
341 $old_local_relname = $self->_inflect_plural(lc $local_table, '_old_to_PL');
344 my $remote_method = 'has_many';
346 # If the local columns have a UNIQUE constraint, this is a one-to-one rel
347 my $local_source = $self->{schema}->source($local_moniker);
348 if (_array_eq([ $local_source->primary_columns ], $local_cols) ||
349 grep { _array_eq($_->[1], $local_cols) } @$uniqs) {
350 $remote_method = 'might_have';
351 $local_relname = $self->_inflect_singular($local_relname_uninflected);
352 $old_local_relname = $self->_inflect_singular($old_local_relname_uninflected);
355 warn __PACKAGE__." $VERSION: renaming ${remote_class} relation '$old_local_relname' to '$local_relname'. This behavior is new as of 0.05003.\n" if $old_local_relname && $local_relname ne $old_local_relname;
357 return ( $local_relname, $remote_relname, $remote_method );
362 See L<DBIx::Class::Schema::Loader/AUTHOR> and L<DBIx::Class::Schema::Loader/CONTRIBUTORS>.
366 This library is free software; you can redistribute it and/or modify it under
367 the same terms as Perl itself.