1 package DBIx::Class::Schema::Loader::RelBuilder;
6 use Carp::Clan qw/^DBIx::Class/;
7 use Lingua::EN::Inflect::Number ();
9 our $VERSION = '0.04999_12';
13 DBIx::Class::Schema::Loader::RelBuilder - Builds relationships for DBIx::Class::Schema::Loader
17 See L<DBIx::Class::Schema::Loader>
21 This class builds relationships for L<DBIx::Class::Schema::Loader>. This
22 is module is not (yet) for external use.
28 Arguments: schema_class (scalar), inflect_plural, inflect_singular
30 C<$schema_class> should be a schema class name, where the source
31 classes have already been set up and registered. Column info, primary
32 key, and unique constraints will be drawn from this schema for all
33 of the existing source monikers.
35 Options inflect_plural and inflect_singular are optional, and are better documented
36 in L<DBIx::Class::Schema::Loader::Base>.
40 Arguments: local_moniker (scalar), fk_info (arrayref)
42 This generates the code for the relationships of a given table.
44 C<local_moniker> is the moniker name of the table which had the REFERENCES
45 statements. The fk_info arrayref's contents should take the form:
49 local_columns => [ 'col2', 'col3' ],
50 remote_columns => [ 'col5', 'col7' ],
51 remote_moniker => 'AnotherTableMoniker',
54 local_columns => [ 'col1', 'col4' ],
55 remote_columns => [ 'col1', 'col2' ],
56 remote_moniker => 'YetAnotherTableMoniker',
61 This method will return the generated relationships as a hashref keyed on the
62 class names. The values are arrayrefs of hashes containing method name and
66 'Some::Source::Class' => [
67 { method => 'belongs_to', arguments => [ 'col1', 'Another::Source::Class' ],
68 { method => 'has_many', arguments => [ 'anothers', 'Yet::Another::Source::Class', 'col15' ],
70 '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 if( ref $self->{inflect_plural} eq 'HASH' ) {
104 return $self->{inflect_plural}->{$relname}
105 if exists $self->{inflect_plural}->{$relname};
107 elsif( ref $self->{inflect_plural} eq 'CODE' ) {
108 my $inflected = $self->{inflect_plural}->($relname);
109 return $inflected if $inflected;
112 return Lingua::EN::Inflect::Number::to_PL($relname);
115 # Singularize a relationship name
116 sub _inflect_singular {
117 my ($self, $relname) = @_;
119 if( ref $self->{inflect_singular} eq 'HASH' ) {
120 return $self->{inflect_singular}->{$relname}
121 if exists $self->{inflect_singular}->{$relname};
123 elsif( ref $self->{inflect_singular} eq 'CODE' ) {
124 my $inflected = $self->{inflect_singular}->($relname);
125 return $inflected if $inflected;
128 return Lingua::EN::Inflect::Number::to_S($relname);
131 # accessor for options to be passed to each generated relationship
132 # type. take single argument, the relationship type name, and returns
133 # either a hashref (if some options are set), or nothing
134 sub _relationship_attrs {
135 my ( $self, $reltype ) = @_;
136 my $r = $self->{relationship_attrs};
137 return unless $r && ( $r->{all} || $r->{$reltype} );
139 my %composite = %{ $r->{all} || {} };
140 if( my $specific = $r->{$reltype} ) {
141 while( my ($k,$v) = each %$specific ) {
151 return unless @$a == @$b;
153 for (my $i = 0; $i < @$a; $i++) {
154 return unless $a->[$i] eq $b->[$i];
160 my ($self, $local_moniker, $local_relname, $local_cols, $uniqs) = @_;
162 my $remote_method = 'has_many';
164 # If the local columns have a UNIQUE constraint, this is a one-to-one rel
165 my $local_source = $self->{schema}->source($local_moniker);
166 if (_array_eq([ $local_source->primary_columns ], $local_cols) ||
167 grep { _array_eq($_->[1], $local_cols) } @$uniqs) {
168 $remote_method = 'might_have';
169 $local_relname = $self->_inflect_singular($local_relname);
172 return ($remote_method, $local_relname);
176 my ($self, $local_moniker, $local_cols) = @_;
178 # get our base set of attrs from _relationship_attrs, if present
179 my $attrs = $self->_relationship_attrs('belongs_to') || {};
181 # If the referring column is nullable, make 'belongs_to' an
182 # outer join, unless explicitly set by relationship_attrs
183 my $nullable = grep { $self->{schema}->source($local_moniker)->column_info($_)->{is_nullable} }
185 $attrs->{join_type} = 'LEFT'
186 if $nullable && !defined $attrs->{join_type};
191 sub _remote_relname {
192 my ($self, $remote_table, $cond) = @_;
195 # for single-column case, set the remote relname to the column
196 # name, to make filter accessors work, but strip trailing _id
197 if(scalar keys %{$cond} == 1) {
198 my ($col) = values %{$cond};
200 $remote_relname = $self->_inflect_singular($col);
203 $remote_relname = $self->_inflect_singular(lc $remote_table);
206 return $remote_relname;
210 my ($self, $local_moniker, $rels, $uniqs) = @_;
214 my $local_table = $self->{schema}->source($local_moniker)->from;
215 my $local_class = $self->{schema}->class($local_moniker);
218 foreach my $rel (@$rels) {
219 next if !$rel->{remote_source};
220 $counters{$rel->{remote_source}}++;
223 foreach my $rel (@$rels) {
224 next if !$rel->{remote_source};
225 my $local_cols = $rel->{local_columns};
226 my $remote_cols = $rel->{remote_columns};
227 my $remote_moniker = $rel->{remote_source};
228 my $remote_obj = $self->{schema}->source($remote_moniker);
229 my $remote_class = $self->{schema}->class($remote_moniker);
230 my $remote_table = $remote_obj->from;
231 $remote_cols ||= [ $remote_obj->primary_columns ];
233 if($#$local_cols != $#$remote_cols) {
234 croak "Column count mismatch: $local_moniker (@$local_cols) "
235 . "$remote_moniker (@$remote_cols)";
239 foreach my $i (0 .. $#$local_cols) {
240 $cond{$remote_cols->[$i]} = $local_cols->[$i];
244 my $remote_relname = $self->_remote_relname($remote_table, \%cond);
246 # If more than one rel between this pair of tables, use the local
247 # col names to distinguish
248 if($counters{$remote_moniker} > 1) {
249 my $colnames = q{_} . join(q{_}, @$local_cols);
250 $local_relname = $self->_inflect_plural(
251 lc($local_table) . $colnames
253 $remote_relname .= $colnames if keys %cond > 1;
255 $local_relname = $self->_inflect_plural(lc $local_table);
258 my %rev_cond = reverse %cond;
260 for (keys %rev_cond) {
261 $rev_cond{"foreign.$_"} = "self.".$rev_cond{$_};
262 delete $rev_cond{$_};
267 ($remote_method, $local_relname) = $self->_uniq_fk_rel($local_moniker, $local_relname, $local_cols, $uniqs);
269 push(@{$all_code->{$local_class}},
270 { method => 'belongs_to',
271 args => [ $remote_relname,
274 $self->_remote_attrs($local_moniker, $local_cols),
279 push(@{$all_code->{$remote_class}},
280 { method => $remote_method,
281 args => [ $local_relname,
284 $self->_relationship_attrs($remote_method),
295 See L<DBIx::Class::Schema::Loader/AUTHOR> and L<DBIx::Class::Schema::Loader/CONTRIBUTORS>.
299 This library is free software; you can redistribute it and/or modify it under
300 the same terms as Perl itself.