X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FRelationship.pm;h=15f1bc65be0d66e8d621009d23c389d09b661f61;hb=8091aa9182ff763aa607dd82f4d61b99f8adab37;hp=14741b0ee30ab594d72ccd4d9ea7f5037d978df2;hpb=656796f2088da66cc80f4eb127c39c923ef3c1dd;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Relationship.pm b/lib/DBIx/Class/Relationship.pm
index 14741b0..15f1bc6 100644
--- a/lib/DBIx/Class/Relationship.pm
+++ b/lib/DBIx/Class/Relationship.pm
@@ -3,7 +3,17 @@ package DBIx::Class::Relationship;
 use strict;
 use warnings;
 
-use base qw/Class::Data::Inheritable/;
+use base qw/DBIx::Class/;
+
+__PACKAGE__->load_own_components(qw/
+  HasMany
+  HasOne
+  BelongsTo
+  Accessor
+  CascadeActions
+  ProxyMethods
+  Base
+/);
 
 __PACKAGE__->mk_classdata('_relationships', { } );
 
@@ -16,192 +26,87 @@ DBIx::Class::Relationship - 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.
+model. It allows you to set up relationships and perform joins on them.
+
+Only the helper methods for setting up standard relationship types
+are documented here. For the basic, lower-level methods, see
+L<DBIx::Class::Relationship::Base>.
 
 =head1 METHODS
 
-=over 4
+All helper methods take the following arguments:
 
-=cut
+  __PACKAGE__>$method_name('relname', 'Foreign::Class', $cond, $attrs);
+  
+Both C<$cond> and C<$attrs> are optional. Pass C<undef> for C<$cond> if
+you want to use the default value for it, but still want to set C<$attrs>.
+See L<DBIx::Class::Relationship::Base> for a list of valid attributes.
 
-sub add_relationship {
-  my ($class, $rel, $f_class, $cond, $attrs) = @_;
-  die "Can't create relationship without join condition" unless $cond;
-  $attrs ||= {};
-  eval "use $f_class;";
-  my %rels = %{ $class->_relationships };
-  $rels{$rel} = { class => $f_class,
-                  cond  => $cond,
-                  attrs => $attrs };
-  $class->_relationships(\%rels);
-  #warn %{$f_class->_columns};
-
-  return unless eval { %{$f_class->_columns}; }; # Foreign class not loaded
-  my %join = (%$attrs, _action => 'join',
-    _aliases => { 'self' => 'me', 'foreign' => $rel },
-    _classes => { 'me' => $class, $rel => $f_class });
-  eval { $class->_cond_resolve($cond, \%join) };
-
-  if ($@) { # If the resolve failed, back out and re-throw the error
-    delete $rels{$rel}; # 
-    $class->_relationships(\%rels);
-    $class->throw("Error creating relationship $rel: $@");
-  }
-  1;
-}
-
-sub _cond_key {
-  my ($self, $attrs, $key) = @_;
-  my $action = $attrs->{_action} || '';
-  if ($action eq 'convert') {
-    unless ($key =~ s/^foreign\.//) {
-      $self->throw("Unable to convert relationship to WHERE clause: invalid key ${key}");
-    }
-    return $key;
-  } elsif ($action eq 'join') {
-    my ($type, $field) = split(/\./, $key);
-    if (my $alias = $attrs->{_aliases}{$type}) {
-      my $class = $attrs->{_classes}{$alias};
-      $self->throw("Unknown column $field on $class as $alias")
-        unless exists $class->_columns->{$field};
-      return join('.', $alias, $field);
-    } else {
-      $self->throw( "Unable to resolve type ${type}: only have aliases for ".
-            join(', ', keys %{$attrs->{_aliases} || {}}) );
-    }
-  }
-  return $self->NEXT::ACTUAL::_cond_key($attrs, $key);
-}
-
-sub _cond_value {
-  my ($self, $attrs, $key, $value) = @_;
-  my $action = $attrs->{_action} || '';
-  if ($action eq 'convert') {
-    unless ($value =~ s/^self\.//) {
-      $self->throw( "Unable to convert relationship to WHERE clause: invalid value ${value}" );
-    }
-    unless ($self->_columns->{$value}) {
-      $self->throw( "Unable to convert relationship to WHERE clause: no such accessor ${value}" );
-    }
-    push(@{$attrs->{bind}}, $self->get_column($value));
-    return '?';
-  } elsif ($action eq 'join') {
-    my ($type, $field) = split(/\./, $value);
-    if (my $alias = $attrs->{_aliases}{$type}) {
-      my $class = $attrs->{_classes}{$alias};
-      $self->throw("Unknown column $field on $class as $alias")
-        unless exists $class->_columns->{$field};
-      return join('.', $alias, $field);
-    } else {
-      $self->throw( "Unable to resolve type ${type}: only have aliases for ".
-            join(', ', keys %{$attrs->{_aliases} || {}}) );
-    }
-  }
-      
-  return $self->NEXT::ACTUAL::_cond_value($attrs, $key, $value)
-}
-
-sub search_related {
-  my $self = shift;
-  return $self->_literal_related('search', @_);
-}
-
-sub count_related {
-  my $self = shift;
-  return $self->_literal_related('count', @_);
-}
-
-sub _literal_related {
-  my $self = shift;
-  my $op = shift;
-  my $meth = "${op}_literal";
-  my $rel = shift;
-  my $attrs = { };
-  if (@_ > 1 && ref $_[$#_] eq 'HASH') {
-    $attrs = { %{ pop(@_) } };
-  }
-  my $rel_obj = $self->_relationships->{$rel};
-  $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
-  $attrs = { %{$rel_obj->{attrs} || {}}, %{$attrs || {}} };
-  my $s_cond;
-  if (@_) {
-    $self->throw( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1));
-    my $query = ((@_ > 1) ? {@_} : shift);
-    $s_cond = $self->_cond_resolve($query, $attrs);
-  }
-  $attrs->{_action} = 'convert'; # shouldn't we resolve the cond to something
-                                 # to merge into the AST really?
-  my ($cond) = $self->_cond_resolve($rel_obj->{cond}, $attrs);
-  $cond = "${s_cond} AND ${cond}" if $s_cond;
-  #warn $rel_obj->{class}." $meth $cond ".join(', ', @{$attrs->{bind}});
-  return $rel_obj->{class}->$meth($cond, @{$attrs->{bind} || []}, $attrs);
-}
-
-sub create_related {
-  my $class = shift;
-  return $class->new_related(@_)->insert;
-}
-
-sub new_related {
-  my ($self, $rel, $values, $attrs) = @_;
-  $self->throw( "Can't call new_related as class method" ) 
-    unless ref $self;
-  $self->throw( "new_related needs a hash" ) 
-    unless (ref $values eq 'HASH');
-  my $rel_obj = $self->_relationships->{$rel};
-  $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
-  $self->throw( "Can't abstract implicit create for ${rel}, condition not a hash" )
-    unless ref $rel_obj->{cond} eq 'HASH';
-  $attrs = { %{$rel_obj->{attrs}}, %{$attrs || {}}, _action => 'convert' };
-  my %fields = %$values;
-  while (my ($k, $v) = each %{$rel_obj->{cond}}) {
-    $self->_cond_value($attrs, $k => $v);
-    $fields{$self->_cond_key($attrs, $k)} = (@{delete $attrs->{bind}})[0];
-  }
-  return $rel_obj->{class}->new(\%fields);
-}
-
-sub find_or_create_related {
-  my $self = shift;
-  return ($self->search_related(@_))[0] || $self->create_related(@_);
-}
-
-sub set_from_related {
-  my ($self, $rel, $f_obj) = @_;
-  my $rel_obj = $self->_relationships->{$rel};
-  $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
-  my $cond = $rel_obj->{cond};
-  $self->throw( "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';
-  $self->throw( "Object $f_obj isn't a ".$rel_obj->{class} )
-    unless $f_obj->isa($rel_obj->{class});
-  foreach my $key (keys %$cond) {
-    next if ref $cond->{$key}; # Skip literals and complex conditions
-    $self->throw("set_from_related can't handle $key as key")
-      unless $key =~ m/^foreign\.([^\.]+)$/;
-    my $val = $f_obj->get_column($1);
-    $self->throw("set_from_related can't handle ".$cond->{$key}." as value")
-      unless $cond->{$key} =~ m/^self\.([^\.]+)$/;
-    $self->set_column($1 => $val);
-  }
-  return 1;
-}
-
-sub update_from_related {
-  my $self = shift;
-  $self->set_from_related(@_);
-  $self->update;
-}
+=head2 belongs_to
 
-1;
+  # in a Bar class (where Foo has many Bars)
+  __PACKAGE__->belongs_to(foo => Foo);
+  my $f_obj = $obj->foo;
+  $obj->foo($new_f_obj);
+
+Creates a relationship where the calling class stores the foreign class's 
+primary key in one (or more) of its columns. If $cond is a column name
+instead of a join condition hash, that is used as the name of the column
+holding the foreign key. If $cond is not given, the relname is used as
+the column name.
+
+NOTE: If you are used to L<Class::DBI> relationships, this is the equivalent
+of C<has_a>.
+
+=head2 has_many
+
+  # in a Foo class (where Foo has many Bars)
+  __PACKAGE__->has_many(bar => Bar, 'foo');
+  my $f_resultset = $obj->foo;
+  my $f_resultset = $obj->foo({ name => { LIKE => '%macaroni%' }, { prefetch => [qw/bar/] });
+  my @f_obj = $obj->foo;
+
+  $obj->add_to_foo(\%col_data);
+
+Creates a one-to-many relationship, where the corresponding elements of the
+foreign class store the calling class's primary key in one (or more) of its
+columns. You should pass the name of the column in the foreign class as the
+$cond argument, or specify a complete join condition.
+
+If you delete an object in a class with a C<has_many> relationship, all
+related objects will be deleted as well. However, any database-level
+cascade or restrict will take precedence.
 
-=back
+=head2 might_have
+
+  __PACKAGE__->might_have(baz => Baz);
+  my $f_obj = $obj->baz; # to get the baz object
+
+Creates an optional one-to-one relationship with a class, where the foreign class 
+stores our primary key in one of its columns. Defaults to the primary key of the
+foreign class unless $cond specifies a column or join condition.
+
+If you update or delete an object in a class with a C<might_have> relationship, 
+the related object will be updated or deleted as well. Any database-level update
+or delete constraints will override this behavior.
+
+=head2 has_one
+
+  __PACKAGE__->has_one(gorch => Gorch);
+  my $f_obj = $obj->gorch;
+
+Creates a one-to-one relationship with another class. This is just like C<might_have>,
+except the implication is that the other object is always present. The only different
+between C<has_one> and C<might_have> is that C<has_one> uses an (ordinary) inner join,
+whereas C<might_have> uses a left join.
+
+=cut
+
+1;
 
 =head1 AUTHORS
 
-Matt S. Trout <perl-stuff@trout.me.uk>
+Matt S. Trout <mst@shadowcatsystems.co.uk>
 
 =head1 LICENSE