X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FRelationship%2FBase.pm;h=f31e6850971ce6e3b1013e8438b7db5b227ee9ff;hb=3d618782661512ffb7b263a222e183808170b88a;hp=6f25075232cdb785344583263d7f6c8676e9b871;hpb=70ecd5a103ed5ab8f674df100da40ff47d4ae658;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Relationship/Base.pm b/lib/DBIx/Class/Relationship/Base.pm
index 6f25075..f31e685 100644
--- a/lib/DBIx/Class/Relationship/Base.pm
+++ b/lib/DBIx/Class/Relationship/Base.pm
@@ -3,11 +3,10 @@ package DBIx::Class::Relationship::Base;
 use strict;
 use warnings;
 
+use Scalar::Util ();
 use base qw/DBIx::Class/;
 
-__PACKAGE__->mk_classdata('_relationships', { } );
-
-=head1 NAME 
+=head1 NAME
 
 DBIx::Class::Relationship::Base - Inter-table relationships
 
@@ -15,28 +14,60 @@ DBIx::Class::Relationship::Base - Inter-table relationships
 
 =head1 DESCRIPTION
 
-This class handles relationships between the tables in your database
-model. It allows your to set up relationships, and to perform joins
-on searches.
+This class provides methods to describe the relationships between the
+tables in your database model. These are the "bare bones" relationships
+methods, for predefined ones, look in L<DBIx::Class::Relationship>.
 
 =head1 METHODS
 
 =head2 add_relationship
 
+=over 4
+
+=item Arguments: 'relname', 'Foreign::Class', $cond, $attrs
+
+=back
+
   __PACKAGE__->add_relationship('relname', 'Foreign::Class', $cond, $attrs);
 
-The condition needs to be an SQL::Abstract-style representation of the
-join between the tables. For example, if you're creating a rel from Foo to Bar,
+The condition needs to be an L<SQL::Abstract>-style representation of the
+join between the tables. When resolving the condition for use in a C<JOIN>,
+keys using the pseudo-table C<foreign> are resolved to mean "the Table on the
+other side of the relationship", and values using the pseudo-table C<self>
+are resolved to mean "the Table this class is representing". Other
+restrictions, such as by value, sub-select and other tables, may also be
+used. Please check your database for C<JOIN> parameter support.
+
+For example, if you're creating a relationship from C<Author> to C<Book>, where
+the C<Book> table has a column C<author_id> containing the ID of the C<Author>
+row:
 
-  { 'foreign.foo_id' => 'self.id' }
+  { 'foreign.author_id' => 'self.id' }
 
-will result in the JOIN clause
+will result in the C<JOIN> clause
 
-  foo me JOIN bar bar ON bar.foo_id = me.id
+  author me JOIN book book ON book.author_id = me.id
 
-You can specify as many foreign => self mappings as necessary.
+For multi-column foreign keys, you will need to specify a C<foreign>-to-C<self>
+mapping for each column in the key. For example, if you're creating a
+relationship from C<Book> to C<Edition>, where the C<Edition> table refers to a
+publisher and a type (e.g. "paperback"):
+
+  {
+    'foreign.publisher_id' => 'self.publisher_id',
+    'foreign.type_id'      => 'self.type_id',
+  }
 
-Valid attributes are as follows:
+This will result in the C<JOIN> clause:
+
+  book me JOIN edition edition ON edition.publisher_id = me.publisher_id
+    AND edition.type_id = me.type_id
+
+Each key-value pair provided in a hashref will be used as C<AND>ed conditions.
+To add an C<OR>ed condition, use an arrayref of hashrefs. See the
+L<SQL::Abstract> documentation for more details.
+
+In addition to standard result set attributes, the following attributes are also valid:
 
 =over 4
 
@@ -48,15 +79,19 @@ command immediately before C<JOIN>.
 
 =item proxy
 
-An arrayref containing a list of accessors in the foreign class to proxy in
+An arrayref containing a list of accessors in the foreign class to create in
 the main class. If, for example, you do the following:
   
-  __PACKAGE__->might_have(bar => 'Bar', undef, { proxy => [ qw/margle/ ] });
+  MyDB::Schema::CD->might_have(liner_notes => 'MyDB::Schema::LinerNotes',
+    undef, {
+      proxy => [ qw/notes/ ],
+    });
   
-Then, assuming Bar has an accessor named margle, you can do:
+Then, assuming MyDB::Schema::LinerNotes has an accessor named notes, you can do:
 
-  my $obj = Foo->find(1);
-  $obj->margle(10); # set margle; Bar object is created if it doesn't exist
+  my $cd = MyDB::Schema::CD->find(1);
+  $cd->notes('Notes go here'); # set notes -- LinerNotes object is
+                               # created if it doesn't exist
   
 =item accessor
 
@@ -67,21 +102,93 @@ related object, but you also want the relationship accessor to double as
 a column accessor). For C<multi> accessors, an add_to_* method is also
 created, which calls C<create_related> for the relationship.
 
+=item is_foreign_key_constraint
+
+If you are using L<SQL::Translator> to create SQL for you and you find that it
+is creating constraints where it shouldn't, or not creating them where it 
+should, set this attribute to a true or false value to override the detection
+of when to create constraints.
+
 =back
 
 =head2 register_relationship
 
-=head3 Arguments: ($relname, $rel_info)
+=over 4
+
+=item Arguments: $relname, $rel_info
 
-Registers a relationship on the class
+=back
+
+Registers a relationship on the class. This is called internally by
+DBIx::Class::ResultSourceProxy to set up Accessors and Proxies.
 
 =cut
 
 sub register_relationship { }
 
+=head2 related_resultset
+
+=over 4
+
+=item Arguments: $relationship_name
+
+=item Return Value: $related_resultset
+
+=back
+
+  $rs = $cd->related_resultset('artist');
+
+Returns a L<DBIx::Class::ResultSet> for the relationship named
+$relationship_name.
+
+=cut
+
+sub related_resultset {
+  my $self = shift;
+  $self->throw_exception("Can't call *_related as class methods")
+    unless ref $self;
+  my $rel = shift;
+  my $rel_obj = $self->relationship_info($rel);
+  $self->throw_exception( "No such relationship ${rel}" )
+    unless $rel_obj;
+  
+  return $self->{related_resultsets}{$rel} ||= do {
+    my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
+    $attrs = { %{$rel_obj->{attrs} || {}}, %$attrs };
+
+    $self->throw_exception( "Invalid query: @_" )
+      if (@_ > 1 && (@_ % 2 == 1));
+    my $query = ((@_ > 1) ? {@_} : shift);
+
+    my $cond = $self->result_source->resolve_condition(
+      $rel_obj->{cond}, $rel, $self
+    );
+    if (ref $cond eq 'ARRAY') {
+      $cond = [ map { my $hash;
+        foreach my $key (keys %$_) {
+          my $newkey = $key =~ /\./ ? "me.$key" : $key;
+          $hash->{$newkey} = $_->{$key};
+        }; $hash } @$cond ];
+    } else {
+      foreach my $key (grep { ! /\./ } keys %$cond) {
+        $cond->{"me.$key"} = delete $cond->{$key};
+      }
+    }
+    $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
+    $self->result_source->related_source($rel)->resultset->search(
+      $query, $attrs
+    );
+  };
+}
+
 =head2 search_related
 
-  My::Table->search_related('relname', $cond, $attrs);
+  @objects = $rs->search_related('relname', $cond, $attrs);
+  $objects_rs = $rs->search_related('relname', $cond, $attrs);
+
+Run a search on a related resultset. The search will be restricted to the
+item or items represented by the L<DBIx::Class::ResultSet> it was called
+upon. This method can be called on a ResultSet, a Row or a ResultSource class.
 
 =cut
 
@@ -89,10 +196,28 @@ sub search_related {
   return shift->related_resultset(shift)->search(@_);
 }
 
+=head2 search_related_rs
+
+  ( $objects_rs ) = $rs->search_related_rs('relname', $cond, $attrs);
+
+This method works exactly the same as search_related, except that 
+it garauntees a restultset, even in list context.
+
+=cut
+
+sub search_related_rs {
+  return shift->related_resultset(shift)->search_rs(@_);
+}
+
 =head2 count_related
 
   $obj->count_related('relname', $cond, $attrs);
 
+Returns the count of all the items in the related resultset, restricted by the
+current item or where conditions. Can be called on a
+L<DBIx::Class::Manual::Glossary/"ResultSet"> or a
+L<DBIx::Class::Manual::Glossary/"Row"> object.
+
 =cut
 
 sub count_related {
@@ -100,9 +225,31 @@ sub count_related {
   return $self->search_related(@_)->count;
 }
 
+=head2 new_related
+
+  my $new_obj = $obj->new_related('relname', \%col_data);
+
+Create a new item of the related foreign class. If called on a
+L<Row|DBIx::Class::Manual::Glossary/"Row"> object, it will magically 
+set any foreign key columns of the new object to the related primary 
+key columns of the source object for you.  The newly created item will 
+not be saved into your storage until you call L<DBIx::Class::Row/insert>
+on it.
+
+=cut
+
+sub new_related {
+  my ($self, $rel, $values, $attrs) = @_;
+  return $self->search_related($rel)->new($values, $attrs);
+}
+
 =head2 create_related
 
-  My::Table->create_related('relname', \%col_data);
+  my $new_obj = $obj->create_related('relname', \%col_data);
+
+Creates a new item, similarly to new_related, and also inserts the item's data
+into your storage medium. See the distinction between C<create> and C<new>
+in L<DBIx::Class::ResultSet> for details.
 
 =cut
 
@@ -114,43 +261,77 @@ sub create_related {
   return $obj;
 }
 
-=head2 new_related
+=head2 find_related
 
-  My::Table->new_related('relname', \%col_data);
+  my $found_item = $obj->find_related('relname', @pri_vals | \%pri_vals);
+
+Attempt to find a related object using its primary key or unique constraints.
+See L<DBIx::Class::ResultSet/find> for details.
 
 =cut
 
-sub new_related {
-  my ($self, $rel, $values, $attrs) = @_;
-  return $self->search_related($rel)->new($values, $attrs);
+sub find_related {
+  my $self = shift;
+  my $rel = shift;
+  return $self->search_related($rel)->find(@_);
 }
 
-=head2 find_related
+=head2 find_or_new_related
 
-  My::Table->find_related('relname', @pri_vals | \%pri_vals);
+  my $new_obj = $obj->find_or_new_related('relname', \%col_data);
+
+Find an item of a related class. If none exists, instantiate a new item of the
+related class. The object will not be saved into your storage until you call
+L<DBIx::Class::Row/insert> on it.
 
 =cut
 
-sub find_related {
+sub find_or_new_related {
   my $self = shift;
-  my $rel = shift;
-  return $self->search_related($rel)->find(@_);
+  return $self->find_related(@_) || $self->new_related(@_);
 }
 
 =head2 find_or_create_related
 
-  My::Table->find_or_create_related('relname', \%col_data);
+  my $new_obj = $obj->find_or_create_related('relname', \%col_data);
+
+Find or create an item of a related class. See
+L<DBIx::Class::ResultSet/find_or_create> for details.
 
 =cut
 
 sub find_or_create_related {
   my $self = shift;
-  return $self->find_related(@_) || $self->create_related(@_);
+  my $obj = $self->find_related(@_);
+  return (defined($obj) ? $obj : $self->create_related(@_));
+}
+
+=head2 update_or_create_related
+
+  my $updated_item = $obj->update_or_create_related('relname', \%col_data, \%attrs?);
+
+Update or create an item of a related class. See
+L<DBIx::Class::ResultSet/update_or_create> for details.
+
+=cut
+
+sub update_or_create_related {
+  my $self = shift;
+  my $rel = shift;
+  return $self->related_resultset($rel)->update_or_create(@_);
 }
 
 =head2 set_from_related
 
-  My::Table->set_from_related('relname', $rel_obj);
+  $book->set_from_related('author', $author_obj);
+
+Set column values on the current object, using related values from the given
+related object. This is used to associate previously separate objects, for
+example, to set the correct author for a book, find the Author object, then
+call set_from_related on the book.
+
+The columns are only set in the local copy of the object, call L</update> to
+set them in the storage.
 
 =cut
 
@@ -159,12 +340,16 @@ sub set_from_related {
   my $rel_obj = $self->relationship_info($rel);
   $self->throw_exception( "No such relationship ${rel}" ) unless $rel_obj;
   my $cond = $rel_obj->{cond};
-  $self->throw_exception( "set_from_related can only handle a hash condition; the "
-    ."condition for $rel is of type ".(ref $cond ? ref $cond : 'plain scalar'))
-      unless ref $cond eq 'HASH';
-  my $f_class = $self->result_source->schema->class($rel_obj->{class});
-  $self->throw_exception( "Object $f_obj isn't a ".$f_class )
-    unless $f_obj->isa($f_class);
+  $self->throw_exception(
+    "set_from_related can only handle a hash condition; the ".
+    "condition for $rel is of type ".
+    (ref $cond ? ref $cond : 'plain scalar')
+  ) unless ref $cond eq 'HASH';
+  if (defined $f_obj) {
+    my $f_class = $self->result_source->schema->class($rel_obj->{class});
+    $self->throw_exception( "Object $f_obj isn't a ".$f_class )
+      unless Scalar::Util::blessed($f_obj) and $f_obj->isa($f_class);
+  }
   $self->set_columns(
     $self->result_source->resolve_condition(
        $rel_obj->{cond}, $f_obj, $rel));
@@ -173,7 +358,10 @@ sub set_from_related {
 
 =head2 update_from_related
 
-  My::Table->update_from_related('relname', $rel_obj);
+  $book->update_from_related('author', $author_obj);
+
+The same as L</"set_from_related">, but the changes are immediately updated
+in storage.
 
 =cut
 
@@ -185,7 +373,9 @@ sub update_from_related {
 
 =head2 delete_related
 
-  My::Table->delete_related('relname', $cond, $attrs);
+  $obj->delete_related('relname', $cond, $attrs);
+
+Delete any related item subject to the given conditions.
 
 =cut
 
@@ -196,66 +386,78 @@ sub delete_related {
   return $obj;
 }
 
-1;
+=head2 add_to_$rel
 
-=head2 related_resultset($name)
+B<Currently only available for C<has_many>, C<many-to-many> and 'multi' type
+relationships.>
 
-Returns a L<DBIx::Class::ResultSet> for the relationship named $name.
+=over 4
 
-  $rs = My::Table->related_resultset('related_table');
+=item Arguments: ($foreign_vals | $obj), $link_vals?
 
-=cut
+=back
 
-sub related_resultset {
-  my $self = shift;
-  $self->throw_exception("Can't call *_related as class methods") unless ref $self;
-  my $rel = shift;
-  $self->{related_resultsets} ||= {};
-  #use Data::Dumper; warn "related_resultsets: ", Dumper $self->{related_resultsets};
-  my $resultsets = $self->{related_resultsets};
-  if( !exists $resultsets->{$rel} ) {
-
-    #warn "creating related resultset for relation '$rel'", \$self;
-    my $source = $self->result_source;
-    # if relation exists but resultset doesn't, create the resultset
-
-    my $attrs = { };
-    if (@_ > 1 && ref $_[$#_] eq 'HASH') {
-      $attrs = { %{ pop(@_) } };
-    }
-  
-    my $rel_obj = $self->relationship_info($rel);
-    $self->throw_exception( "No such relationship ${rel}" ) unless $rel_obj;
-    $attrs = { %{$rel_obj->{attrs} || {}}, %{$attrs || {}} };
+  my $role = $schema->resultset('Role')->find(1);
+  $actor->add_to_roles($role);
+      # creates a My::DBIC::Schema::ActorRoles linking table row object
 
-    $self->throw_exception( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1));
-    my $query = ((@_ > 1) ? {@_} : shift);
+  $actor->add_to_roles({ name => 'lead' }, { salary => 15_000_000 });
+      # creates a new My::DBIC::Schema::Role row object and the linking table
+      # object with an extra column in the link
 
-    my ($cond) = $self->result_source->resolve_condition($rel_obj->{cond}, $rel, $self);
-    if (ref $cond eq 'ARRAY') {
-      $cond = [ map { my %hash;
-        foreach my $key (keys %{$_}) {
-          unless ($key =~ m/\./) {
-            $hash{"me.$key"} = $_->{$key};
-          } else {
-           $hash{$key} = $_->{$key};
-          }
-        }; \%hash; } @$cond ];
-      } else {
-      foreach my $key (keys %$cond) {
-        unless ($key =~ m/\./) {
-          $cond->{"me.$key"} = delete $cond->{$key};
-        }
-      }
-    }
-    $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
-    #use Data::Dumper; warn Dumper($cond);
-    #warn $rel_obj->{class}." $meth $cond ".join(', ', @{$attrs->{bind}||[]});
-    $resultsets->{$rel} = 
-      $self->result_source->related_source($rel)->resultset->search($query, $attrs);
-  }
-  return $resultsets->{$rel};
-}
+Adds a linking table object for C<$obj> or C<$foreign_vals>. If the first
+argument is a hash reference, the related object is created first with the
+column values in the hash. If an object reference is given, just the linking
+table object is created. In either case, any additional column values for the
+linking table object can be specified in C<$link_vals>.
+
+=head2 set_$rel
+
+B<Currently only available for C<many-to-many> relationships.>
+
+=over 4
+
+=item Arguments: (\@hashrefs | \@objs)
+
+=back
+
+  my $actor = $schema->resultset('Actor')->find(1);
+  my @roles = $schema->resultset('Role')->search({ role => 
+     { '-in' -> ['Fred', 'Barney'] } } );
+
+  $actor->set_roles(\@roles);
+     # Replaces all of $actor's previous roles with the two named
+
+Replace all the related objects with the given reference to a list of
+objects. This does a C<delete> B<on the link table resultset> to remove the
+association between the current object and all related objects, then calls
+C<add_to_$rel> repeatedly to link all the new objects.
+
+Note that this means that this method will B<not> delete any objects in the
+table on the right side of the relation, merely that it will delete the link
+between them.
+
+Due to a mistake in the original implementation of this method, it will also
+accept a list of objects or hash references. This is B<deprecated> and will be
+removed in a future version.
+
+=head2 remove_from_$rel
+
+B<Currently only available for C<many-to-many> relationships.>
+
+=over 4
+
+=item Arguments: $obj
+
+=back
+
+  my $role = $schema->resultset('Role')->find(1);
+  $actor->remove_from_roles($role);
+      # removes $role's My::DBIC::Schema::ActorRoles linking table row object
+
+Removes the link between the current object and the related object. Note that
+the related object itself won't be deleted unless you call ->delete() on
+it. This method just removes the link between the two objects.
 
 =head1 AUTHORS
 
@@ -267,3 +469,4 @@ You may distribute this code under the same terms as Perl itself.
 
 =cut
 
+1;