X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FRelationship%2FBase.pm;h=c3733e7cfa5707707a192d4ab64f11546d00bd47;hb=880a1a0cc6a48a3165656fe5daf7ec288901c3e2;hp=c7fa8611717d4d6c07fe09d7890d2f2fc08bec95;hpb=503536d5b216b4d85ed3f5420f3db93d4c033d86;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Relationship/Base.pm b/lib/DBIx/Class/Relationship/Base.pm
index c7fa861..c3733e7 100644
--- a/lib/DBIx/Class/Relationship/Base.pm
+++ b/lib/DBIx/Class/Relationship/Base.pm
@@ -3,264 +3,247 @@ package DBIx::Class::Relationship::Base;
 use strict;
 use warnings;
 
-use base qw/Class::Data::Inheritable/;
-
-__PACKAGE__->mk_classdata('_relationships', { } );
+use base qw/DBIx::Class/;
 
 =head1 NAME 
 
-DBIx::Class::Relationship - Inter-table relationships
+DBIx::Class::Relationship::Base - Inter-table relationships
 
 =head1 SYNOPSIS
 
 =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 add_relationship
+=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
+join between the tables. When resolving the condition for use in a JOIN,
+keys using the pseudo-table I<foreign> are resolved to mean "the Table on the
+other side of the relationship", and values using the pseudo-table I<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 JOIN parameter support.
+
+For example, if you're creating a rel from Author to Book, where the Book
+table has a column author_id containing the ID of the Author row:
 
-  { 'foreign.foo_id' => 'self.id' }
+  { 'foreign.author_id' => 'self.id' }
 
-will result in a JOIN clause like
+will result in the JOIN clause
 
-  foo me JOIN bar bar ON bar.foo_id = me.id
+  author me JOIN book book ON bar.author_id = me.id
+
+You can specify as many foreign => self mappings as necessary. Each key/value
+pair provided in a hashref will be used as ANDed conditions, to add an ORed
+condition, use an arrayref of hashrefs. See the L<SQL::Abstract> documentation
+for more details.
+
+Valid attributes are as follows:
+
+=over 4
+
+=item join_type
+
+Explicitly specifies the type of join to use in the relationship. Any SQL
+join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in the SQL
+command immediately before C<JOIN>.
+
+=item proxy
+
+An arrayref containing a list of accessors in the foreign class to create in
+the main class. If, for example, you do the following:
+  
+  MyDB::Schema::CD->might_have(liner_notes => 'MyDB::Schema::LinerNotes',
+    undef, {
+      proxy => [ qw/notes/ ],
+    });
+  
+Then, assuming MyDB::Schema::LinerNotes has an accessor named notes, you can do:
+
+  my $cd = MyDB::Schema::CD->find(1);
+  $cd->notes('Notes go here'); # set notes -- LinerNotes object is
+                               # created if it doesn't exist
+  
+=item accessor
+
+Specifies the type of accessor that should be created for the relationship.
+Valid values are C<single> (for when there is only a single related object),
+C<multi> (when there can be many), and C<filter> (for when there is a single
+related object, but you also want the relationship accessor to double as
+a column accessor). For C<multi> accessors, an add_to_* method is also
+created, which calls C<create_related> for the relationship.
+
+=back
+
+=head2 register_relationship
+
+=over 4
+
+=item Arguments: ($relname, $rel_info)
+
+=back
+
+Registers a relationship on the class. This is called internally by
+L<DBIx::Class::ResultSourceProxy> to set up Accessors and Proxies.
 
 =cut
 
-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
-  eval { $class->_resolve_join($rel, 'me') };
-
-  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 register_relationship { }
 
-sub _resolve_join {
-  my ($class, $join, $alias) = @_;
-  if (ref $join eq 'ARRAY') {
-    return map { $class->_resolve_join($_, $alias) } @$join;
-  } elsif (ref $join eq 'HASH') {
-    return map { $class->_resolve_join($_, $alias),
-                 $class->_relationships->{$_}{class}->_resolve_join($join->{$_}, $_) }
-           keys %$join;
-  } elsif (ref $join) {
-    $class->throw("No idea how to resolve join reftype ".ref $join);
-  } else {
-    my $rel_obj = $class->_relationships->{$join};
-    $class->throw("No such relationship ${join}") unless $rel_obj;
-    my $j_class = $rel_obj->{class};
-    my %join = (_action => 'join',
-         _aliases => { 'self' => $alias, 'foreign' => $join },
-         _classes => { $alias => $class, $join => $j_class });
-    my $j_cond = $j_class->resolve_condition($rel_obj->{cond}, \%join);
-    return [ { $join => $j_class->_table_name,
-               -join_type => $rel_obj->{attrs}{join_type} || '' }, $j_cond ];
-  }
-}
+=head2 related_resultset
 
-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 :(");
-  }
-}
+=over 4
 
-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, $key);
-}
+=item Arguments: ($relationship_name)
 
-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}" );
-    }
-    return $self->get_column($value);
-  } 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);
+=item Returns: $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 {
-      $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 $self->NEXT::ACTUAL::_cond_value($attrs, $key, $value)
+    $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
+    $self->result_source->related_source($rel)->resultset->search(
+      $query, $attrs
+    );
+  };
 }
 
-=item search_related
+=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;
-  return $self->_query_related('search', @_);
+  return shift->related_resultset(shift)->search(@_);
 }
 
-=item count_related
+=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
 
 sub count_related {
   my $self = shift;
-  return $self->_query_related('count', @_);
+  return $self->search_related(@_)->count;
 }
 
-sub _query_related {
-  my $self = shift;
-  my $meth = shift;
-  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 || {}} };
-
-  $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 $self->resolve_class($rel_obj->{class}
-           )->$meth($query, $attrs);
-}
+=head2 new_related
 
-=item create_related
+  my $new_obj = $obj->new_related('relname', \%col_data);
 
-  My::Table->create_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;
-  return $class->new_related(@_)->insert;
+sub new_related {
+  my ($self, $rel, $values, $attrs) = @_;
+  return $self->search_related($rel)->new($values, $attrs);
 }
 
-=item 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) = @_;
-  $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}}, %{$attrs || {}}, _action => 'convert' };
-
-  my %fields = %{$self->resolve_condition($rel_obj->{cond},$attrs)};
-  $fields{$_} = $values->{$_} for keys %$values;
-
-  return $self->resolve_class($rel_obj->{class})->new(\%fields);
+sub create_related {
+  my $self = shift;
+  my $rel = shift;
+  my $obj = $self->search_related($rel)->create(@_);
+  delete $self->{related_resultsets}->{$rel};
+  return $obj;
 }
 
-=item find_related
+=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
 
 sub find_related {
   my $self = shift;
   my $rel = shift;
-  my $rel_obj = $self->_relationships->{$rel};
-  $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
-  my ($cond) = $self->resolve_condition($rel_obj->{cond}, { _action => 'convert' });
-  $self->throw( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1));
-  my $attrs = { };
-  if (@_ > 1 && ref $_[$#_] eq 'HASH') {
-    $attrs = { %{ pop(@_) } };
-  }
-  my $query = ((@_ > 1) ? {@_} : shift);
-  $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
-  return $self->resolve_class($rel_obj->{class})->find($query);
+  return $self->search_related($rel)->find(@_);
 }
 
-=item find_or_create_related
+=head2 find_or_create_related
+
+  my $new_obj = $obj->find_or_create_related('relname', \%col_data);
 
-  My::Table->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
 
@@ -269,38 +252,45 @@ sub find_or_create_related {
   return $self->find_related(@_) || $self->create_related(@_);
 }
 
-=item set_from_related
+=head2 set_from_related
+
+  $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.
 
-  My::Table->set_from_related('relname', $rel_obj);
+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 = $self->_relationships->{$rel};
-  $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
+  my $rel_obj = $self->relationship_info($rel);
+  $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 = $self->resolve_class($rel_obj->{class});
-  $self->throw( "Object $f_obj isn't a ".$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';
+  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);
-  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->set_columns(
+    $self->result_source->resolve_condition(
+       $rel_obj->{cond}, $f_obj, $rel));
   return 1;
 }
 
-=item update_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
 
@@ -310,21 +300,23 @@ sub update_from_related {
   $self->update;
 }
 
-=item delete_related
+=head2 delete_related
+
+  $obj->delete_related('relname', $cond, $attrs);
 
-  My::Table->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;
 
-=back
-
 =head1 AUTHORS
 
 Matt S. Trout <mst@shadowcatsystems.co.uk>