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1 | package DBIx::Class::Relationship::Base; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | |
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6 | use base qw/DBIx::Class/; |
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7 | |
8 | __PACKAGE__->mk_classdata('_relationships', { } ); |
9 | |
10 | =head1 NAME |
11 | |
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12 | DBIx::Class::Relationship::Base - Inter-table relationships |
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13 | |
14 | =head1 SYNOPSIS |
15 | |
16 | =head1 DESCRIPTION |
17 | |
18 | This class handles relationships between the tables in your database |
19 | model. It allows your to set up relationships, and to perform joins |
20 | on searches. |
21 | |
22 | =head1 METHODS |
23 | |
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24 | =head2 add_relationship |
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25 | |
26 | __PACKAGE__->add_relationship('relname', 'Foreign::Class', $cond, $attrs); |
27 | |
28 | The condition needs to be an SQL::Abstract-style representation of the |
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29 | join between the tables. For example, if you're creating a rel from Foo to Bar, |
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30 | |
31 | { 'foreign.foo_id' => 'self.id' } |
32 | |
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33 | will result in the JOIN clause |
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34 | |
35 | foo me JOIN bar bar ON bar.foo_id = me.id |
36 | |
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37 | You can specify as many foreign => self mappings as necessary. |
38 | |
39 | Valid attributes are as follows: |
40 | |
41 | =over 4 |
42 | |
43 | =item join_type |
44 | |
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>. |
48 | |
49 | =item proxy |
50 | |
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: |
53 | |
54 | __PACKAGE__->might_have(bar => 'Bar', undef, { proxy => qw[/ margle /] }); |
55 | |
56 | Then, assuming Bar has an accessor named margle, you can do: |
57 | |
58 | my $obj = Foo->find(1); |
59 | $obj->margle(10); # set margle; Bar object is created if it doesn't exist |
60 | |
61 | =item accessor |
62 | |
63 | Specifies the type of accessor that should be created for the relationship. |
64 | Valid values are C<single> (for when there is only a single related object), |
65 | C<multi> (when there can be many), and C<filter> (for when there is a single |
66 | related object, but you also want the relationship accessor to double as |
67 | a column accessor). For C<multi> accessors, an add_to_* method is also |
68 | created, which calls C<create_related> for the relationship. |
69 | |
70 | =back |
71 | |
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72 | =cut |
73 | |
74 | sub add_relationship { |
75 | my ($class, $rel, $f_class, $cond, $attrs) = @_; |
76 | die "Can't create relationship without join condition" unless $cond; |
77 | $attrs ||= {}; |
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78 | eval "require $f_class;"; |
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79 | if ($@) { |
80 | $class->throw($@) unless $@ =~ /Can't locate/; |
81 | } |
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82 | my %rels = %{ $class->_relationships }; |
83 | $rels{$rel} = { class => $f_class, |
84 | cond => $cond, |
85 | attrs => $attrs }; |
86 | $class->_relationships(\%rels); |
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87 | |
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88 | return unless eval { $f_class->can('columns'); }; # Foreign class not loaded |
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89 | eval { $class->_resolve_join($rel, 'me') }; |
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90 | |
91 | if ($@) { # If the resolve failed, back out and re-throw the error |
92 | delete $rels{$rel}; # |
93 | $class->_relationships(\%rels); |
94 | $class->throw("Error creating relationship $rel: $@"); |
95 | } |
96 | 1; |
97 | } |
98 | |
fef5d100 |
99 | sub _resolve_join { |
100 | my ($class, $join, $alias) = @_; |
101 | if (ref $join eq 'ARRAY') { |
102 | return map { $class->_resolve_join($_, $alias) } @$join; |
103 | } elsif (ref $join eq 'HASH') { |
104 | return map { $class->_resolve_join($_, $alias), |
105 | $class->_relationships->{$_}{class}->_resolve_join($join->{$_}, $_) } |
106 | keys %$join; |
107 | } elsif (ref $join) { |
108 | $class->throw("No idea how to resolve join reftype ".ref $join); |
109 | } else { |
110 | my $rel_obj = $class->_relationships->{$join}; |
111 | $class->throw("No such relationship ${join}") unless $rel_obj; |
112 | my $j_class = $rel_obj->{class}; |
113 | my %join = (_action => 'join', |
114 | _aliases => { 'self' => $alias, 'foreign' => $join }, |
115 | _classes => { $alias => $class, $join => $j_class }); |
116 | my $j_cond = $j_class->resolve_condition($rel_obj->{cond}, \%join); |
117 | return [ { $join => $j_class->_table_name, |
118 | -join_type => $rel_obj->{attrs}{join_type} || '' }, $j_cond ]; |
119 | } |
120 | } |
121 | |
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122 | sub resolve_condition { |
123 | my ($self, $cond, $attrs) = @_; |
124 | if (ref $cond eq 'HASH') { |
125 | my %ret; |
126 | foreach my $key (keys %$cond) { |
127 | my $val = $cond->{$key}; |
128 | if (ref $val) { |
129 | $self->throw("Can't handle this yet :("); |
130 | } else { |
131 | $ret{$self->_cond_key($attrs => $key)} |
132 | = $self->_cond_value($attrs => $key => $val); |
133 | } |
134 | } |
135 | return \%ret; |
136 | } else { |
137 | $self->throw("Can't handle this yet :("); |
138 | } |
139 | } |
140 | |
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141 | sub _cond_key { |
142 | my ($self, $attrs, $key) = @_; |
143 | my $action = $attrs->{_action} || ''; |
144 | if ($action eq 'convert') { |
145 | unless ($key =~ s/^foreign\.//) { |
146 | $self->throw("Unable to convert relationship to WHERE clause: invalid key ${key}"); |
147 | } |
148 | return $key; |
149 | } elsif ($action eq 'join') { |
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150 | return $key unless $key =~ /\./; |
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151 | my ($type, $field) = split(/\./, $key); |
152 | if (my $alias = $attrs->{_aliases}{$type}) { |
153 | my $class = $attrs->{_classes}{$alias}; |
154 | $self->throw("Unknown column $field on $class as $alias") |
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155 | unless $class->has_column($field); |
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156 | return join('.', $alias, $field); |
157 | } else { |
158 | $self->throw( "Unable to resolve type ${type}: only have aliases for ". |
159 | join(', ', keys %{$attrs->{_aliases} || {}}) ); |
160 | } |
161 | } |
147dd158 |
162 | return $self->next::method($attrs, $key); |
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163 | } |
164 | |
165 | sub _cond_value { |
166 | my ($self, $attrs, $key, $value) = @_; |
167 | my $action = $attrs->{_action} || ''; |
168 | if ($action eq 'convert') { |
169 | unless ($value =~ s/^self\.//) { |
170 | $self->throw( "Unable to convert relationship to WHERE clause: invalid value ${value}" ); |
171 | } |
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172 | unless ($self->has_column($value)) { |
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173 | $self->throw( "Unable to convert relationship to WHERE clause: no such accessor ${value}" ); |
174 | } |
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175 | return $self->get_column($value); |
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176 | } elsif ($action eq 'join') { |
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177 | return $key unless $key =~ /\./; |
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178 | my ($type, $field) = split(/\./, $value); |
179 | if (my $alias = $attrs->{_aliases}{$type}) { |
180 | my $class = $attrs->{_classes}{$alias}; |
181 | $self->throw("Unknown column $field on $class as $alias") |
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182 | unless $class->has_column($field); |
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183 | return join('.', $alias, $field); |
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184 | } else { |
185 | $self->throw( "Unable to resolve type ${type}: only have aliases for ". |
186 | join(', ', keys %{$attrs->{_aliases} || {}}) ); |
187 | } |
188 | } |
189 | |
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190 | return $self->next::method($attrs, $key, $value) |
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191 | } |
192 | |
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193 | =head2 search_related |
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194 | |
195 | My::Table->search_related('relname', $cond, $attrs); |
196 | |
197 | =cut |
198 | |
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199 | sub search_related { |
200 | my $self = shift; |
201 | return $self->_query_related('search', @_); |
202 | } |
203 | |
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204 | =head2 count_related |
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205 | |
206 | My::Table->count_related('relname', $cond, $attrs); |
207 | |
208 | =cut |
209 | |
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210 | sub count_related { |
211 | my $self = shift; |
212 | return $self->_query_related('count', @_); |
213 | } |
214 | |
215 | sub _query_related { |
216 | my $self = shift; |
217 | my $meth = shift; |
218 | my $rel = shift; |
219 | my $attrs = { }; |
220 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
221 | $attrs = { %{ pop(@_) } }; |
222 | } |
223 | my $rel_obj = $self->_relationships->{$rel}; |
224 | $self->throw( "No such relationship ${rel}" ) unless $rel_obj; |
225 | $attrs = { %{$rel_obj->{attrs} || {}}, %{$attrs || {}} }; |
226 | |
227 | $self->throw( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1)); |
228 | my $query = ((@_ > 1) ? {@_} : shift); |
229 | |
230 | $attrs->{_action} = 'convert'; # shouldn't we resolve the cond to something |
231 | # to merge into the AST really? |
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232 | my ($cond) = $self->resolve_condition($rel_obj->{cond}, $attrs); |
233 | $query = ($query ? { '-and' => [ $cond, $query ] } : $cond); |
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234 | #use Data::Dumper; warn Dumper($query); |
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235 | #warn $rel_obj->{class}." $meth $cond ".join(', ', @{$attrs->{bind}||[]}); |
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236 | delete $attrs->{_action}; |
237 | return $self->resolve_class($rel_obj->{class} |
238 | )->$meth($query, $attrs); |
239 | } |
240 | |
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241 | =head2 create_related |
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242 | |
243 | My::Table->create_related('relname', \%col_data); |
244 | |
245 | =cut |
246 | |
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247 | sub create_related { |
248 | my $class = shift; |
249 | return $class->new_related(@_)->insert; |
250 | } |
251 | |
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252 | =head2 new_related |
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253 | |
254 | My::Table->new_related('relname', \%col_data); |
255 | |
256 | =cut |
257 | |
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258 | sub new_related { |
259 | my ($self, $rel, $values, $attrs) = @_; |
260 | $self->throw( "Can't call new_related as class method" ) |
261 | unless ref $self; |
262 | $self->throw( "new_related needs a hash" ) |
263 | unless (ref $values eq 'HASH'); |
264 | my $rel_obj = $self->_relationships->{$rel}; |
265 | $self->throw( "No such relationship ${rel}" ) unless $rel_obj; |
266 | $self->throw( "Can't abstract implicit create for ${rel}, condition not a hash" ) |
267 | unless ref $rel_obj->{cond} eq 'HASH'; |
268 | $attrs = { %{$rel_obj->{attrs}}, %{$attrs || {}}, _action => 'convert' }; |
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269 | |
270 | my %fields = %{$self->resolve_condition($rel_obj->{cond},$attrs)}; |
271 | $fields{$_} = $values->{$_} for keys %$values; |
272 | |
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273 | return $self->resolve_class($rel_obj->{class})->new(\%fields); |
274 | } |
275 | |
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276 | =head2 find_related |
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277 | |
278 | My::Table->find_related('relname', @pri_vals | \%pri_vals); |
279 | |
280 | =cut |
281 | |
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282 | sub find_related { |
283 | my $self = shift; |
284 | my $rel = shift; |
285 | my $rel_obj = $self->_relationships->{$rel}; |
286 | $self->throw( "No such relationship ${rel}" ) unless $rel_obj; |
287 | my ($cond) = $self->resolve_condition($rel_obj->{cond}, { _action => 'convert' }); |
288 | $self->throw( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1)); |
289 | my $attrs = { }; |
290 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
291 | $attrs = { %{ pop(@_) } }; |
292 | } |
293 | my $query = ((@_ > 1) ? {@_} : shift); |
294 | $query = ($query ? { '-and' => [ $cond, $query ] } : $cond); |
295 | return $self->resolve_class($rel_obj->{class})->find($query); |
296 | } |
297 | |
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298 | =head2 find_or_create_related |
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299 | |
300 | My::Table->find_or_create_related('relname', \%col_data); |
301 | |
302 | =cut |
303 | |
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304 | sub find_or_create_related { |
305 | my $self = shift; |
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306 | return $self->find_related(@_) || $self->create_related(@_); |
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307 | } |
308 | |
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309 | =head2 set_from_related |
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310 | |
311 | My::Table->set_from_related('relname', $rel_obj); |
312 | |
313 | =cut |
314 | |
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315 | sub set_from_related { |
316 | my ($self, $rel, $f_obj) = @_; |
317 | my $rel_obj = $self->_relationships->{$rel}; |
318 | $self->throw( "No such relationship ${rel}" ) unless $rel_obj; |
319 | my $cond = $rel_obj->{cond}; |
320 | $self->throw( "set_from_related can only handle a hash condition; the " |
321 | ."condition for $rel is of type ".(ref $cond ? ref $cond : 'plain scalar')) |
322 | unless ref $cond eq 'HASH'; |
323 | my $f_class = $self->resolve_class($rel_obj->{class}); |
324 | $self->throw( "Object $f_obj isn't a ".$f_class ) |
325 | unless $f_obj->isa($f_class); |
326 | foreach my $key (keys %$cond) { |
327 | next if ref $cond->{$key}; # Skip literals and complex conditions |
328 | $self->throw("set_from_related can't handle $key as key") |
329 | unless $key =~ m/^foreign\.([^\.]+)$/; |
330 | my $val = $f_obj->get_column($1); |
331 | $self->throw("set_from_related can't handle ".$cond->{$key}." as value") |
332 | unless $cond->{$key} =~ m/^self\.([^\.]+)$/; |
333 | $self->set_column($1 => $val); |
334 | } |
335 | return 1; |
336 | } |
337 | |
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338 | =head2 update_from_related |
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339 | |
340 | My::Table->update_from_related('relname', $rel_obj); |
341 | |
342 | =cut |
343 | |
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344 | sub update_from_related { |
345 | my $self = shift; |
346 | $self->set_from_related(@_); |
347 | $self->update; |
348 | } |
349 | |
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350 | =head2 delete_related |
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351 | |
352 | My::Table->delete_related('relname', $cond, $attrs); |
353 | |
354 | =cut |
355 | |
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356 | sub delete_related { |
357 | my $self = shift; |
358 | return $self->search_related(@_)->delete; |
359 | } |
360 | |
361 | 1; |
362 | |
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363 | =head1 AUTHORS |
364 | |
daec44b8 |
365 | Matt S. Trout <mst@shadowcatsystems.co.uk> |
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366 | |
367 | =head1 LICENSE |
368 | |
369 | You may distribute this code under the same terms as Perl itself. |
370 | |
371 | =cut |
372 | |