X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FRelationship%2FBase.pm;h=05f4c52ba0e9a50b6b8808530eb3935c0912ea31;hb=9c2c91ea7f94d7981cd1c8d212a4b04751fcd023;hp=35f906725662ccda689d1216847f8d3a5f5505c3;hpb=87772e46b99bc03f36c5a82ec29282a3228c29c7;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Relationship/Base.pm b/lib/DBIx/Class/Relationship/Base.pm
index 35f9067..05f4c52 100644
--- a/lib/DBIx/Class/Relationship/Base.pm
+++ b/lib/DBIx/Class/Relationship/Base.pm
@@ -5,9 +5,7 @@ use warnings;
 
 use base qw/DBIx::Class/;
 
-__PACKAGE__->mk_classdata('_relationships', { } );
-
-=head1 NAME 
+=head1 NAME
 
 DBIx::Class::Relationship::Base - Inter-table relationships
 
@@ -15,26 +13,58 @@ 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.author_id' => 'self.id' }
+
+will result in the C<JOIN> clause
+
+  author me JOIN book book ON book.author_id = me.id
 
-  { 'foreign.foo_id' => 'self.id' }
+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"):
 
-will result in the JOIN clause
+  {
+    'foreign.publisher_id' => 'self.publisher_id',
+    'foreign.type_id'      => 'self.type_id',
+  }
+
+This will result in the C<JOIN> clause:
 
-  foo me JOIN bar bar ON bar.foo_id = me.id
+  book me JOIN edition edition ON edition.publisher_id = me.publisher_id
+    AND edition.type_id = me.type_id
 
-You can specify as many foreign => self mappings as necessary.
+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.
 
 Valid attributes are as follows:
 
@@ -48,15 +78,19 @@ 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
 
@@ -69,129 +103,98 @@ created, which calls C<create_related> for the relationship.
 
 =back
 
+=head2 register_relationship
+
+=over 4
+
+=item Arguments: $relname, $rel_info
+
+=back
+
+Registers a relationship on the class. This is called internally by
+DBIx::Class::ResultSourceProxy to set up Accessors and Proxies.
+
 =cut
 
-sub add_relationship {
-  shift->result_source->add_relationship(@_);
-}
+sub register_relationship { }
 
-sub relationships {
-  shift->result_source->relationships(@_);
-}
+=head2 related_resultset
 
-sub relationship_info {
-  shift->result_source->relationship_info(@_);
-}
+=over 4
 
-sub resolve_condition {
-  my ($self, $cond, $attrs) = @_;
-  if (ref $cond eq 'HASH') {
-    my %ret;
-    foreach my $key (keys %$cond) {
-      my $val = $cond->{$key};
-      if (ref $val) {
-        $self->throw("Can't handle this yet :(");
-      } else {
-        $ret{$self->_cond_key($attrs => $key)}
-          = $self->_cond_value($attrs => $key => $val);
-      }
-    }
-    return \%ret;
-  } else {
-   $self->throw("Can't handle this yet :(");
-  }
-}
+=item Arguments: $relationship_name
 
-sub _cond_key {
-  my ($self, $attrs, $key, $alias) = @_;
-  my $action = $attrs->{_action} || '';
-  if ($action eq 'convert') {
-    unless ($key =~ s/^foreign\.//) {
-      $self->throw("Unable to convert relationship to WHERE clause: invalid key ${key}");
-    }
-    if (defined (my $alias = $attrs->{_aliases}{foreign})) {
-      return "${alias}.${key}";
-    } else {
-      return $key;
-    }
-  } elsif ($action eq 'join') {
-    return $key unless $key =~ /\./;
-    my ($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 $class->has_column($field);
-      return join('.', $alias, $field);
-    } else {
-      $self->throw( "Unable to resolve type ${type}: only have aliases for ".
-            join(', ', keys %{$attrs->{_aliases} || {}}) );
-    }
-  }
-  return $self->next::method($attrs, $key);
-}
+=item Return Value: $related_resultset
 
-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->has_column($value)) {
-      $self->throw( "Unable to convert relationship to WHERE clause: no such accessor ${value}" );
-    }
-    return $self->get_column($value);
-  } elsif ($action eq 'join') {
-    return $key unless $key =~ /\./;
-    my ($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 $class->has_column($field);
-      return join('.', $alias, $field);
+=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 {
-      $self->throw( "Unable to resolve type ${type}: only have aliases for ".
-            join(', ', keys %{$attrs->{_aliases} || {}}) );
+      foreach my $key (grep { ! /\./ } keys %$cond) {
+        $cond->{"me.$key"} = delete $cond->{$key};
+      }
     }
-  }
-      
-  return $self->next::method($attrs, $key, $value)
+    $query = ($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);
+  $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
 
 sub search_related {
-  my $self = shift;
-  my $rel = shift;
-  my $attrs = { };
-  if (@_ > 1 && ref $_[$#_] eq 'HASH') {
-    $attrs = { %{ pop(@_) } };
-  }
-  my $rel_obj = $self->relationship_info($rel);
-  $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
-  $attrs = { %{$rel_obj->{attrs} || {}}, %{$attrs || {}} };
-
-  $self->throw( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1));
-  my $query = ((@_ > 1) ? {@_} : shift);
-
-  $attrs->{_action} = 'convert'; # shouldn't we resolve the cond to something
-                                 # to merge into the AST really?
-  my ($cond) = $self->resolve_condition($rel_obj->{cond}, $attrs);
-  $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
-  #use Data::Dumper; warn Dumper($query);
-  #warn $rel_obj->{class}." $meth $cond ".join(', ', @{$attrs->{bind}||[]});
-  delete $attrs->{_action};
-  return $self->result_source->schema->resultset($rel_obj->{class}
-           )->search($query, $attrs);
+  return shift->related_resultset(shift)->search(@_);
 }
 
 =head2 count_related
 
-  My::Table->count_related('relname', $cond, $attrs);
+  $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
 
@@ -200,32 +203,47 @@ sub count_related {
   return $self->search_related(@_)->count;
 }
 
-=head2 create_related
+=head2 new_related
 
-  My::Table->create_related('relname', \%col_data);
+  my $new_obj = $obj->new_related('relname', \%col_data);
+
+Create a new item of the related foreign class. If called on a
+L<DBIx::Class::Manual::Glossary/"Row"> object, it will magically set any
+primary key values into foreign key columns 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 create_related {
-  my $class = shift;
-  my $rel = shift;
-  return $class->search_related($rel)->create(@_);
+sub new_related {
+  my ($self, $rel, $values, $attrs) = @_;
+  return $self->search_related($rel)->new($values, $attrs);
 }
 
-=head2 new_related
+=head2 create_related
+
+  my $new_obj = $obj->create_related('relname', \%col_data);
 
-  My::Table->new_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
 
-sub new_related {
-  my ($self, $rel, $values, $attrs) = @_;
-  return $self->search_related($rel)->new($values, $attrs);
+sub create_related {
+  my $self = shift;
+  my $rel = shift;
+  my $obj = $self->search_related($rel)->create(@_);
+  delete $self->{related_resultsets}->{$rel};
+  return $obj;
 }
 
 =head2 find_related
 
-  My::Table->find_related('relname', @pri_vals | \%pri_vals);
+  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
 
@@ -237,47 +255,60 @@ sub find_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 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
 
 sub set_from_related {
   my ($self, $rel, $f_obj) = @_;
   my $rel_obj = $self->relationship_info($rel);
-  $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
+  $self->throw_exception( "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';
-  my $f_class = $self->result_source->schema->class($rel_obj->{class});
-  $self->throw( "Object $f_obj isn't a ".$f_class )
-    unless $f_obj->isa($f_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);
+  $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 $f_obj->isa($f_class);
   }
+  $self->set_columns(
+    $self->result_source->resolve_condition(
+       $rel_obj->{cond}, $f_obj, $rel));
   return 1;
 }
 
 =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
 
@@ -289,13 +320,17 @@ 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
 
 sub delete_related {
   my $self = shift;
-  return $self->search_related(@_)->delete;
+  my $obj = $self->search_related(@_)->delete;
+  delete $self->{related_resultsets}->{$_[0]};
+  return $obj;
 }
 
 1;