Move discard_changes code to Row.pm, better docs

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / PK.pm

diff --git a/lib/DBIx/Class/PK.pm b/lib/DBIx/Class/PK.pm
index 32165dc..cf8a194 100644 (file)
--- a/lib/DBIx/Class/PK.pm
+++ b/lib/DBIx/Class/PK.pm
@@ -3,11 +3,9 @@ package DBIx::Class::PK;
 use strict;
 use warnings;
 
-use base qw/Class::Data::Inheritable DBIx::Class::SQL/;
+use base qw/DBIx::Class::Row/;
 
-__PACKAGE__->mk_classdata('_primaries' => {});
-
-=head1 NAME 
+=head1 NAME
 
 DBIx::Class::PK - Primary Key class
 
@@ -15,84 +13,91 @@ DBIx::Class::PK - Primary Key class
 
 =head1 DESCRIPTION
 
-This class represents methods handling primary keys
-and depending on them.
+This class contains methods for handling primary keys and methods
+depending on them.
 
 =head1 METHODS
 
-=over 4
-
 =cut
 
+=head2 id
+
+Returns the primary key(s) for a row. Can't be called as
+a class method.
+
+=cut
 
-sub _ident_cond {
-  my ($class) = @_;
-  return join(" AND ", map { "$_ = ?" } keys %{$class->_primaries});
+sub id {
+  my ($self) = @_;
+  $self->throw_exception( "Can't call id() as a class method" )
+    unless ref $self;
+  my @pk = $self->_ident_values;
+  return (wantarray ? @pk : $pk[0]);
 }
 
 sub _ident_values {
   my ($self) = @_;
-  return (map { $self->{_column_data}{$_} } keys %{$self->_primaries});
+  return (map { $self->{_column_data}{$_} } $self->primary_columns);
 }
 
-sub set_primary_key {
-  my ($class, @cols) = @_;
-  my %pri;
-  $pri{$_} = {} for @cols;
-  $class->_primaries(\%pri);
-}
+=head2 ID
 
-sub retrieve {
-  my ($class, @vals) = @_;
-  my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {});
-  my @pk = keys %{$class->_primaries};
-  die "Can't retrieve unless primary columns are defined" unless @pk;
-  my $query;
-  if (ref $vals[0] eq 'HASH') {
-    $query = $vals[0];
-  } elsif (@pk == @vals) {
-    my $ret = ($class->retrieve_from_sql($class->_ident_cond, @vals, $attrs))[0];
-    #warn "$class: ".join(', ', %{$ret->{_column_data}});
-    return $ret;
-  } else {
-    $query = {@vals};
-  }
-  die "Can't retrieve unless all primary keys are specified"
-    unless (keys %$query >= @pk); # If we check 'em we run afoul of uc/lc
-                                  # column names etc. Not sure what to do yet
-  my $ret = ($class->search($query))[0];
-  #warn "$class: ".join(', ', %{$ret->{_column_data}});
-  return $ret;
-}
+Returns a unique id string identifying a row object by primary key.
+Used by L<DBIx::Class::CDBICompat::LiveObjectIndex> and
+L<DBIx::Class::ObjectCache>.
+
+=over
+
+=item WARNING
+
+The default C<_create_ID> method used by this function orders the returned
+values by the alphabetical order of the primary column names, B<unlike>
+the L</id> method, which follows the same order in which columns were fed
+to L<DBIx::Class::ResultSource/set_primary_key>.
+
+=back
 
-sub discard_changes {
+=cut
+
+sub ID {
   my ($self) = @_;
-  delete $self->{_dirty_columns};
-  return unless $self->in_database; # Don't reload if we aren't real!
-  my ($reload) = $self->retrieve($self->id);
-  unless ($reload) { # If we got deleted in the mean-time
-    $self->in_database(0);
-    return $self;
-  }
-  $self->store_column($_ => $reload->get_column($_))
-    foreach keys %{$self->_columns};
-  return $self;
+  $self->throw_exception( "Can't call ID() as a class method" )
+    unless ref $self;
+  return undef unless $self->in_storage;
+  return $self->_create_ID(map { $_ => $self->{_column_data}{$_} }
+                             $self->primary_columns);
 }
 
-sub id {
-  my ($self) = @_;
-  die "Can't call id() as a class method" unless ref $self;
-  my @pk = $self->_ident_values;
-  return (wantarray ? @pk : $pk[0]);
+sub _create_ID {
+  my ($self,%vals) = @_;
+  return undef unless 0 == grep { !defined } values %vals;
+  return join '|', ref $self || $self, $self->result_source->name,
+    map { $_ . '=' . $vals{$_} } sort keys %vals;
 }
 
-1;
+=head2 ident_condition
 
-=back
+  my $cond = $result_source->ident_condition();
+
+  my $cond = $result_source->ident_condition('alias');
+
+Produces a condition hash to locate a row based on the primary key(s).
+
+=cut
+
+sub ident_condition {
+  my ($self, $alias) = @_;
+  my %cond;
+  my $prefix = defined $alias ? $alias.'.' : '';
+  $cond{$prefix.$_} = $self->get_column($_) for $self->primary_columns;
+  return \%cond;
+}
+
+1;
 
 =head1 AUTHORS
 
-Matt S. Trout <perl-stuff@trout.me.uk>
+Matt S. Trout <mst@shadowcatsystems.co.uk>
 
 =head1 LICENSE