1 package DBIx::Class::Schema::Loader::RelBuilder;
6 use Carp::Clan qw/^DBIx::Class/;
7 use Lingua::EN::Inflect::Phrase ();
8 use DBIx::Class::Schema::Loader::Utils 'split_name';
10 our $VERSION = '0.07000';
14 DBIx::Class::Schema::Loader::RelBuilder - Builds relationships for DBIx::Class::Schema::Loader
18 See L<DBIx::Class::Schema::Loader> and L<DBIx::Class::Schema::Loader::Base>.
22 This class builds relationships for L<DBIx::Class::Schema::Loader>. This
23 is module is not (yet) for external use.
29 Arguments: schema_class (scalar), inflect_plural, inflect_singular
31 C<$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' => [
80 my ( $class, $schema, $inflect_pl, $inflect_singular, $rel_attrs ) = @_;
84 inflect_plural => $inflect_pl,
85 inflect_singular => $inflect_singular,
86 relationship_attrs => $rel_attrs,
89 # validate the relationship_attrs arg
90 if( defined $self->{relationship_attrs} ) {
91 ref($self->{relationship_attrs}) eq 'HASH'
92 or croak "relationship_attrs must be a hashref";
95 return bless $self => $class;
99 # pluralize a relationship name
100 sub _inflect_plural {
101 my ($self, $relname) = @_;
103 return '' if !defined $relname || $relname eq '';
105 if( ref $self->{inflect_plural} eq 'HASH' ) {
106 return $self->{inflect_plural}->{$relname}
107 if exists $self->{inflect_plural}->{$relname};
109 elsif( ref $self->{inflect_plural} eq 'CODE' ) {
110 my $inflected = $self->{inflect_plural}->($relname);
111 return $inflected if $inflected;
114 return $self->_to_PL($relname);
117 # Singularize a relationship name
118 sub _inflect_singular {
119 my ($self, $relname) = @_;
121 return '' if !defined $relname || $relname eq '';
123 if( ref $self->{inflect_singular} eq 'HASH' ) {
124 return $self->{inflect_singular}->{$relname}
125 if exists $self->{inflect_singular}->{$relname};
127 elsif( ref $self->{inflect_singular} eq 'CODE' ) {
128 my $inflected = $self->{inflect_singular}->($relname);
129 return $inflected if $inflected;
132 return $self->_to_S($relname);
136 my ($self, $name) = @_;
139 my $plural = Lingua::EN::Inflect::Phrase::to_PL($name);
146 my ($self, $name) = @_;
149 my $singular = Lingua::EN::Inflect::Phrase::to_S($name);
150 $singular =~ s/ /_/g;
155 sub _default_relationship_attrs { +{
165 on_delete => 'CASCADE',
166 on_update => 'CASCADE',
167 # is_deferrable => 1,
171 # accessor for options to be passed to each generated relationship
172 # type. take single argument, the relationship type name, and returns
173 # either a hashref (if some options are set), or nothing
174 sub _relationship_attrs {
175 my ( $self, $reltype ) = @_;
176 my $r = $self->{relationship_attrs};
179 %{ $self->_default_relationship_attrs->{$reltype} || {} },
183 if( my $specific = $r->{$reltype} ) {
184 while( my ($k,$v) = each %$specific ) {
192 my ($self, $a, $b) = @_;
194 return unless @$a == @$b;
196 for (my $i = 0; $i < @$a; $i++) {
197 return unless $a->[$i] eq $b->[$i];
203 my ($self, $local_moniker, $local_cols) = @_;
205 # get our base set of attrs from _relationship_attrs, if present
206 my $attrs = $self->_relationship_attrs('belongs_to') || {};
208 # If the referring column is nullable, make 'belongs_to' an
209 # outer join, unless explicitly set by relationship_attrs
210 my $nullable = grep { $self->{schema}->source($local_moniker)->column_info($_)->{is_nullable} } @$local_cols;
211 $attrs->{join_type} = 'LEFT' if $nullable && !defined $attrs->{join_type};
216 sub _normalize_name {
217 my ($self, $name) = @_;
219 my @words = split_name $name;
221 return join '_', map lc, @words;
224 sub _remote_relname {
225 my ($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};
232 $col = $self->_normalize_name($col);
234 $remote_relname = $self->_inflect_singular($col);
237 $remote_relname = $self->_inflect_singular($self->_normalize_name($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 = $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, $local_relname_uninflected);
323 if ( $counters->{$remote_moniker} > 1) {
324 my $colnames = q{_} . $self->_normalize_name(join '_', @$local_cols);
325 $remote_relname .= $colnames if keys %$cond > 1;
327 $local_relname = $self->_normalize_name($local_table . $colnames);
328 $local_relname =~ s/_id$//;
330 $local_relname_uninflected = $local_relname;
331 $local_relname = $self->_inflect_plural($local_relname);
333 $local_relname_uninflected = $self->_normalize_name($local_table);
334 $local_relname = $self->_inflect_plural($self->_normalize_name($local_table));
337 my $remote_method = 'has_many';
339 # If the local columns have a UNIQUE constraint, this is a one-to-one rel
340 my $local_source = $self->{schema}->source($local_moniker);
341 if ($self->_array_eq([ $local_source->primary_columns ], $local_cols) ||
342 grep { $self->_array_eq($_->[1], $local_cols) } @$uniqs) {
343 $remote_method = 'might_have';
344 $local_relname = $self->_inflect_singular($local_relname_uninflected);
347 return ( $local_relname, $remote_relname, $remote_method );
352 See L<DBIx::Class::Schema::Loader/AUTHOR> and L<DBIx::Class::Schema::Loader/CONTRIBUTORS>.
356 This library is free software; you can redistribute it and/or modify it under
357 the same terms as Perl itself.
362 # vim:et sts=4 sw=4 tw=0: