X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits%2FDBIx-Class.git;a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FInflateColumn.pm;h=5d9c19d460240e6ed867b0f660a5c668fa885df3;hp=7a8a6139e478b52662c481c86f9e27eeb3063ab6;hb=9b2c0de65a57ab32a0a18293ad49fa30f70fee31;hpb=484c9dda865880cd4e1cda8e0117f1d073a6aa7e

diff --git a/lib/DBIx/Class/InflateColumn.pm b/lib/DBIx/Class/InflateColumn.pm
index 7a8a613..5d9c19d 100644
--- a/lib/DBIx/Class/InflateColumn.pm
+++ b/lib/DBIx/Class/InflateColumn.pm
@@ -2,77 +2,202 @@ package DBIx::Class::InflateColumn;
 
 use strict;
 use warnings;
+use Scalar::Util qw/blessed/;
+
+use base qw/DBIx::Class::Row/;
+
+=head1 NAME
+
+DBIx::Class::InflateColumn - Automatically create references from column data
+
+=head1 SYNOPSIS
+
+    # In your table classes
+    __PACKAGE__->inflate_column('column_name', {
+        inflate => sub { ... },
+        deflate => sub { ... },
+    });
+
+=head1 DESCRIPTION
+
+This component translates column data into references, i.e. "inflating"
+the column data. It also "deflates" references into an appropriate format
+for the database.
+
+It can be used, for example, to automatically convert to and from
+L<DateTime> objects for your date and time fields. There's a
+convenience component to actually do that though, try
+L<DBIx::Class::InflateColumn::DateTime>.
+
+It will handle all types of references except scalar references. It
+will not handle scalar values, these are ignored and thus passed
+through to L<SQL::Abstract>. This is to allow setting raw values to
+"just work". Scalar references are passed through to the database to
+deal with, to allow such settings as C< \'year + 1'> and C< \'DEFAULT' >
+to work.
+
+If you want to filter plain scalar values and replace them with
+something else, see L<DBIx::Class::FilterColumn>.
+
+=head1 METHODS
+
+=head2 inflate_column
+
+Instruct L<DBIx::Class> to inflate the given column.
+
+In addition to the column name, you must provide C<inflate> and
+C<deflate> methods. The C<inflate> method is called when you access
+the field, while the C<deflate> method is called when the field needs
+to used by the database.
+
+For example, if you have a table C<events> with a timestamp field
+named C<insert_time>, you could inflate the column in the
+corresponding table class using something like:
+
+    __PACKAGE__->inflate_column('insert_time', {
+        inflate => sub { DateTime::Format::Pg->parse_datetime(shift); },
+        deflate => sub { DateTime::Format::Pg->format_datetime(shift); },
+    });
+
+(Replace L<DateTime::Format::Pg> with the appropriate module for your
+database, or consider L<DateTime::Format::DBI>.)
+
+The coderefs you set for inflate and deflate are called with two parameters,
+the first is the value of the column to be inflated/deflated, the second is the
+row object itself. Thus you can call C<< ->result_source->schema->storage->dbh >> in your inflate/defalte subs, to feed to L<DateTime::Format::DBI>.
+
+In this example, calls to an event's C<insert_time> accessor return a
+L<DateTime> object. This L<DateTime> object is later "deflated" when
+used in the database layer.
+
+=cut
 
 sub inflate_column {
   my ($self, $col, $attrs) = @_;
-  die "No such column $col to inflate" unless exists $self->_columns->{$col};
-  die "inflate_column needs attr hashref" unless ref $attrs eq 'HASH';
-  $self->_columns->{$col}{_inflate_info} = $attrs;
-  $self->mk_group_accessors('inflated_column' => $col);
+  $self->throw_exception("No such column $col to inflate")
+    unless $self->has_column($col);
+  $self->throw_exception("inflate_column needs attr hashref")
+    unless ref $attrs eq 'HASH';
+  $self->column_info($col)->{_inflate_info} = $attrs;
+  my $acc = $self->column_info($col)->{accessor};
+  $self->mk_group_accessors('inflated_column' => [ (defined $acc ? $acc : $col), $col]);
   return 1;
 }
 
 sub _inflated_column {
   my ($self, $col, $value) = @_;
   return $value unless defined $value; # NULL is NULL is NULL
-  return $value unless exists $self->_columns->{$col}{_inflate_info};
-  return $value unless exists $self->_columns->{$col}{_inflate_info}{inflate};
-  my $inflate = $self->_columns->{$col}{_inflate_info}{inflate};
+  my $info = $self->column_info($col)
+    or $self->throw_exception("No column info for $col");
+  return $value unless exists $info->{_inflate_info};
+  my $inflate = $info->{_inflate_info}{inflate};
+  $self->throw_exception("No inflator for $col") unless defined $inflate;
   return $inflate->($value, $self);
 }
 
 sub _deflated_column {
   my ($self, $col, $value) = @_;
-  return $value unless ref $value; # If it's not an object, don't touch it
-  return $value unless exists $self->_columns->{$col}{_inflate_info};
-  return $value unless exists $self->_columns->{$col}{_inflate_info}{deflate};
-  my $deflate = $self->_columns->{$col}{_inflate_info}{deflate};
+#  return $value unless ref $value && blessed($value); # If it's not an object, don't touch it
+  ## Leave scalar refs (ala SQL::Abstract literal SQL), untouched, deflate all other refs
+  return $value unless (ref $value && ref($value) ne 'SCALAR');
+  my $info = $self->column_info($col) or
+    $self->throw_exception("No column info for $col");
+  return $value unless exists $info->{_inflate_info};
+  my $deflate = $info->{_inflate_info}{deflate};
+  $self->throw_exception("No deflator for $col") unless defined $deflate;
   return $deflate->($value, $self);
 }
 
+=head2 get_inflated_column
+
+  my $val = $obj->get_inflated_column($col);
+
+Fetch a column value in its inflated state.  This is directly
+analogous to L<DBIx::Class::Row/get_column> in that it only fetches a
+column already retrieved from the database, and then inflates it.
+Throws an exception if the column requested is not an inflated column.
+
+=cut
+
 sub get_inflated_column {
   my ($self, $col) = @_;
-  $self->throw("$col is not an inflated column") unless
-    exists $self->_columns->{$col}{_inflate_info};
-
+  $self->throw_exception("$col is not an inflated column")
+    unless exists $self->column_info($col)->{_inflate_info};
   return $self->{_inflated_column}{$col}
     if exists $self->{_inflated_column}{$col};
-  return $self->{_inflated_column}{$col} =
-           $self->_inflated_column($col, $self->get_column($col));
-}
 
-sub set_inflated_column {
-  my ($self, $col, @rest) = @_;
-  my $ret = $self->store_inflated_column($col, @rest);
-  $self->{_dirty_columns}{$col} = 1;
-  return $ret;
+  my $val = $self->get_column($col);
+  return $val if ref $val eq 'SCALAR';  #that would be a not-yet-reloaded sclarref update
+
+  return $self->{_inflated_column}{$col} = $self->_inflated_column($col, $val);
 }
 
-sub store_inflated_column {
-  my ($self, $col, $obj) = @_;
-  unless (ref $obj) {
+=head2 set_inflated_column
+
+  my $copy = $obj->set_inflated_column($col => $val);
+
+Sets a column value from an inflated value.  This is directly
+analogous to L<DBIx::Class::Row/set_column>.
+
+=cut
+
+sub set_inflated_column {
+  my ($self, $col, $inflated) = @_;
+  $self->set_column($col, $self->_deflated_column($col, $inflated));
+#  if (blessed $inflated) {
+  if (ref $inflated && ref($inflated) ne 'SCALAR') {
+    $self->{_inflated_column}{$col} = $inflated;
+  } else {
     delete $self->{_inflated_column}{$col};
-    return $self->store_column($col, $obj);
   }
+  return $inflated;
+}
 
-  my $deflated = $self->_deflated_column($col, $obj);
-           # Do this now so we don't store if it's invalid
+=head2 store_inflated_column
 
-  $self->{_inflated_column}{$col} = $obj;
-  #warn "Storing $obj: ".($obj->_ident_values)[0];
-  $self->store_column($col, $deflated);
-  return $obj;
-}
+  my $copy = $obj->store_inflated_column($col => $val);
 
-sub new {
-  my ($class, $attrs, @rest) = @_;
-  $attrs ||= {};
-  foreach my $key (keys %$attrs) {
-    if (ref $attrs->{$key} && exists $class->_columns->{$key}{_inflate_info}) {
-      $attrs->{$key} = $class->_deflated_column($key, $attrs->{$key});
-    }
+Sets a column value from an inflated value without marking the column
+as dirty. This is directly analogous to L<DBIx::Class::Row/store_column>.
+
+=cut
+
+sub store_inflated_column {
+  my ($self, $col, $inflated) = @_;
+#  unless (blessed $inflated) {
+  unless (ref $inflated && ref($inflated) ne 'SCALAR') {
+      delete $self->{_inflated_column}{$col};
+      $self->store_column($col => $inflated);
+      return $inflated;
   }
-  return $class->NEXT::ACTUAL::new($attrs, @rest);
+  delete $self->{_column_data}{$col};
+  return $self->{_inflated_column}{$col} = $inflated;
 }
 
+=head1 SEE ALSO
+
+=over 4
+
+=item L<DBIx::Class::Core> - This component is loaded as part of the
+      C<core> L<DBIx::Class> components; generally there is no need to
+      load it directly
+
+=back
+
+=head1 AUTHOR
+
+Matt S. Trout <mst@shadowcatsystems.co.uk>
+
+=head1 CONTRIBUTORS
+
+Daniel Westermann-Clark <danieltwc@cpan.org> (documentation)
+
+Jess Robinson <cpan@desert-island.demon.co.uk>
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+
+=cut
+
 1;