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1 | package DBIx::Class::Schema::Loader::RelBuilder; |
2 | |
3 | use strict; |
4 | use warnings; |
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5 | use Class::C3; |
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6 | use Carp::Clan qw/^DBIx::Class/; |
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7 | use Lingua::EN::Inflect::Number (); |
8 | |
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9 | our $VERSION = '0.05003'; |
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10 | |
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11 | =head1 NAME |
12 | |
13 | DBIx::Class::Schema::Loader::RelBuilder - Builds relationships for DBIx::Class::Schema::Loader |
14 | |
15 | =head1 SYNOPSIS |
16 | |
17 | See L<DBIx::Class::Schema::Loader> |
18 | |
19 | =head1 DESCRIPTION |
20 | |
21 | This class builds relationships for L<DBIx::Class::Schema::Loader>. This |
22 | is module is not (yet) for external use. |
23 | |
24 | =head1 METHODS |
25 | |
26 | =head2 new |
27 | |
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28 | Arguments: schema_class (scalar), inflect_plural, inflect_singular |
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29 | |
30 | C<$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. |
34 | |
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35 | Options inflect_plural and inflect_singular are optional, and are better documented |
36 | in L<DBIx::Class::Schema::Loader::Base>. |
37 | |
38 | =head2 generate_code |
39 | |
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40 | Arguments: local_moniker (scalar), fk_info (arrayref) |
41 | |
42 | This generates the code for the relationships of a given table. |
43 | |
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: |
46 | |
47 | [ |
48 | { |
49 | local_columns => [ 'col2', 'col3' ], |
50 | remote_columns => [ 'col5', 'col7' ], |
51 | remote_moniker => 'AnotherTableMoniker', |
52 | }, |
53 | { |
54 | local_columns => [ 'col1', 'col4' ], |
55 | remote_columns => [ 'col1', 'col2' ], |
56 | remote_moniker => 'YetAnotherTableMoniker', |
57 | }, |
58 | # ... |
59 | ], |
60 | |
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 |
63 | arguments, like so: |
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64 | |
65 | { |
66 | 'Some::Source::Class' => [ |
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67 | { method => 'belongs_to', arguments => [ 'col1', 'Another::Source::Class' ], |
68 | { method => 'has_many', arguments => [ 'anothers', 'Yet::Another::Source::Class', 'col15' ], |
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69 | ], |
70 | 'Another::Source::Class' => [ |
71 | # ... |
72 | ], |
73 | # ... |
74 | } |
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75 | |
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76 | =cut |
77 | |
78 | sub new { |
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79 | |
80 | my ( $class, $schema, $inflect_pl, $inflect_singular, $rel_attrs ) = @_; |
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81 | |
82 | my $self = { |
83 | schema => $schema, |
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84 | inflect_plural => $inflect_pl, |
85 | inflect_singular => $inflect_singular, |
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86 | relationship_attrs => $rel_attrs, |
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87 | }; |
88 | |
c8c27020 |
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"; |
93 | } |
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94 | |
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95 | return bless $self => $class; |
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96 | } |
97 | |
98 | |
99 | # pluralize a relationship name |
100 | sub _inflect_plural { |
101 | my ($self, $relname) = @_; |
102 | |
103 | if( ref $self->{inflect_plural} eq 'HASH' ) { |
104 | return $self->{inflect_plural}->{$relname} |
105 | if exists $self->{inflect_plural}->{$relname}; |
106 | } |
107 | elsif( ref $self->{inflect_plural} eq 'CODE' ) { |
108 | my $inflected = $self->{inflect_plural}->($relname); |
109 | return $inflected if $inflected; |
110 | } |
111 | |
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112 | return Lingua::EN::Inflect::Number::to_PL($relname); |
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113 | } |
114 | |
115 | # Singularize a relationship name |
116 | sub _inflect_singular { |
117 | my ($self, $relname) = @_; |
118 | |
119 | if( ref $self->{inflect_singular} eq 'HASH' ) { |
120 | return $self->{inflect_singular}->{$relname} |
121 | if exists $self->{inflect_singular}->{$relname}; |
122 | } |
123 | elsif( ref $self->{inflect_singular} eq 'CODE' ) { |
124 | my $inflected = $self->{inflect_singular}->($relname); |
125 | return $inflected if $inflected; |
126 | } |
127 | |
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128 | return Lingua::EN::Inflect::Number::to_S($relname); |
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129 | } |
130 | |
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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} ); |
138 | |
139 | my %composite = %{ $r->{all} || {} }; |
140 | if( my $specific = $r->{$reltype} ) { |
141 | while( my ($k,$v) = each %$specific ) { |
142 | $composite{$k} = $v; |
143 | } |
144 | } |
145 | return \%composite; |
146 | } |
147 | |
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148 | sub _array_eq { |
149 | my ($a, $b) = @_; |
150 | |
151 | return unless @$a == @$b; |
152 | |
153 | for (my $i = 0; $i < @$a; $i++) { |
154 | return unless $a->[$i] eq $b->[$i]; |
155 | } |
156 | return 1; |
157 | } |
158 | |
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159 | sub _uniq_fk_rel { |
160 | my ($self, $local_moniker, $local_relname, $local_cols, $uniqs) = @_; |
161 | |
162 | my $remote_method = 'has_many'; |
163 | |
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); |
170 | } |
171 | |
172 | return ($remote_method, $local_relname); |
173 | } |
174 | |
175 | sub _remote_attrs { |
176 | my ($self, $local_moniker, $local_cols) = @_; |
177 | |
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178 | # get our base set of attrs from _relationship_attrs, if present |
179 | my $attrs = $self->_relationship_attrs('belongs_to') || {}; |
180 | |
181 | # If the referring column is nullable, make 'belongs_to' an |
182 | # outer join, unless explicitly set by relationship_attrs |
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183 | my $nullable = grep { $self->{schema}->source($local_moniker)->column_info($_)->{is_nullable} } |
184 | @$local_cols; |
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185 | $attrs->{join_type} = 'LEFT' |
186 | if $nullable && !defined $attrs->{join_type}; |
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187 | |
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188 | return $attrs; |
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189 | } |
190 | |
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191 | sub _remote_relname { |
192 | my ($self, $remote_table, $cond) = @_; |
193 | |
194 | my $remote_relname; |
195 | # for single-column case, set the remote relname to the column |
196 | # name, to make filter accessors work, but strip trailing _id |
197 | if(scalar keys %{$cond} == 1) { |
198 | my ($col) = values %{$cond}; |
199 | $col =~ s/_id$//; |
200 | $remote_relname = $self->_inflect_singular($col); |
201 | } |
202 | else { |
203 | $remote_relname = $self->_inflect_singular(lc $remote_table); |
204 | } |
205 | |
206 | return $remote_relname; |
207 | } |
208 | |
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209 | sub generate_code { |
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210 | my ($self, $local_moniker, $rels, $uniqs) = @_; |
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211 | |
212 | my $all_code = {}; |
213 | |
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214 | my $local_table = $self->{schema}->source($local_moniker)->from; |
215 | my $local_class = $self->{schema}->class($local_moniker); |
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216 | |
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217 | my %counters; |
218 | foreach my $rel (@$rels) { |
219 | next if !$rel->{remote_source}; |
220 | $counters{$rel->{remote_source}}++; |
221 | } |
222 | |
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 ||= [ $remote_obj->primary_columns ]; |
232 | |
233 | if($#$local_cols != $#$remote_cols) { |
234 | croak "Column count mismatch: $local_moniker (@$local_cols) " |
235 | . "$remote_moniker (@$remote_cols)"; |
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236 | } |
237 | |
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238 | my %cond; |
239 | foreach my $i (0 .. $#$local_cols) { |
240 | $cond{$remote_cols->[$i]} = $local_cols->[$i]; |
241 | } |
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242 | |
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243 | my $local_relname; |
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244 | my $remote_relname = $self->_remote_relname($remote_table, \%cond); |
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245 | |
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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); |
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250 | $remote_relname .= $colnames if keys %cond > 1; |
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251 | |
252 | my $is_singular = |
253 | ($self->_uniq_fk_rel($local_moniker, 'dummy', $local_cols, $uniqs))[0] ne 'has_many'; |
254 | |
255 | $local_relname = $self->_multi_rel_local_relname( |
256 | $remote_class, $local_table, $local_cols, $is_singular |
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257 | ); |
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258 | } else { |
259 | $local_relname = $self->_inflect_plural(lc $local_table); |
260 | } |
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261 | |
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262 | my %rev_cond = reverse %cond; |
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263 | |
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264 | for (keys %rev_cond) { |
265 | $rev_cond{"foreign.$_"} = "self.".$rev_cond{$_}; |
266 | delete $rev_cond{$_}; |
267 | } |
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268 | |
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269 | my ($remote_method); |
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270 | |
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271 | ($remote_method, $local_relname) = $self->_uniq_fk_rel($local_moniker, $local_relname, $local_cols, $uniqs); |
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272 | |
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273 | push(@{$all_code->{$local_class}}, |
274 | { method => 'belongs_to', |
275 | args => [ $remote_relname, |
276 | $remote_class, |
277 | \%cond, |
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278 | $self->_remote_attrs($local_moniker, $local_cols), |
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279 | ], |
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280 | } |
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281 | ); |
282 | |
283 | push(@{$all_code->{$remote_class}}, |
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284 | { method => $remote_method, |
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285 | args => [ $local_relname, |
286 | $local_class, |
287 | \%rev_cond, |
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288 | $self->_relationship_attrs($remote_method), |
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289 | ], |
290 | } |
291 | ); |
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292 | } |
293 | |
294 | return $all_code; |
295 | } |
296 | |
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297 | sub _multi_rel_local_relname { |
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298 | my ($self, $remote_class, $local_table, $local_cols, $is_singular) = @_; |
299 | |
300 | my $inflect = $is_singular ? '_inflect_singular' : '_inflect_plural'; |
301 | $inflect = $self->can($inflect); |
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302 | |
303 | my $colnames = q{_} . join(q{_}, @$local_cols); |
304 | my $old_relname = #< TODO: remove me after 0.05003 release |
305 | my $local_relname = lc($local_table) . $colnames; |
306 | my $stripped_id = $local_relname =~ s/_id$//; #< strip off any trailing _id |
e9c09ed9 |
307 | $local_relname = $self->$inflect( $local_relname ); |
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308 | |
309 | # TODO: remove me after 0.05003 release |
e9c09ed9 |
310 | $old_relname = $self->$inflect( $old_relname ); |
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311 | warn __PACKAGE__." $VERSION: warning, stripping trailing _id from ${remote_class} relation '$old_relname', renaming to '$local_relname'. This behavior is new as of 0.05003.\n" |
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312 | if $stripped_id; |
313 | |
314 | return $local_relname; |
315 | } |
316 | |
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317 | =head1 AUTHOR |
318 | |
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319 | See L<DBIx::Class::Schema::Loader/AUTHOR> and L<DBIx::Class::Schema::Loader/CONTRIBUTORS>. |
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320 | |
321 | =head1 LICENSE |
322 | |
323 | This library is free software; you can redistribute it and/or modify it under |
324 | the same terms as Perl itself. |
325 | |
326 | =cut |
327 | |
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328 | 1; |