X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FInflateColumn.pm;h=6b06cb091fba89f50f395efd9c955caa3c98979a;hb=096f421241;hp=7619e5ab061524edde997ed4a7fd740d5ded4604;hpb=147dd158cf91465b8a48adce738d56b85f7d1b9b;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/InflateColumn.pm b/lib/DBIx/Class/InflateColumn.pm
index 7619e5a..6b06cb0 100644
--- a/lib/DBIx/Class/InflateColumn.pm
+++ b/lib/DBIx/Class/InflateColumn.pm
@@ -2,11 +2,71 @@ 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 objects 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 objects, i.e. "inflating"
+the column data. It also "deflates" objects 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.
+
+=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 >> on
+it, 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 $self->has_column($col);
-  die "inflate_column needs attr hashref" unless ref $attrs eq 'HASH';
+  $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;
   $self->mk_group_accessors('inflated_column' => $col);
   return 1;
@@ -15,67 +75,195 @@ sub inflate_column {
 sub _inflated_column {
   my ($self, $col, $value) = @_;
   return $value unless defined $value; # NULL is NULL is NULL
-  my $info = $self->column_info($col) || die "No column info for $col";
+  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};
-  die "No inflator for $col" unless defined $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
-  my $info = $self->column_info($col) || die "No column info for $col";
+  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};
-  die "No deflator for $col" unless defined $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 retreived 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 $self->column_info($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));
 }
 
+=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, @rest) = @_;
-  my $ret = $self->store_inflated_column($col, @rest);
-  $self->{_dirty_columns}{$col} = 1;
-  return $ret;
+  my ($self, $col, $obj) = @_;
+  $self->set_column($col, $self->_deflated_column($col, $obj));
+  if (blessed $obj) {
+    $self->{_inflated_column}{$col} = $obj; 
+  } else {
+    delete $self->{_inflated_column}{$col};      
+  }
+  return $obj;
 }
 
+=head2 store_inflated_column
+
+  my $copy = $obj->store_inflated_column($col => $val);
+
+Sets a column value from an inflated value without marking the column
+as dirty. This is directly analogous to L<DBIx::Class::Row/store_column>.
+
+=cut
+
 sub store_inflated_column {
   my ($self, $col, $obj) = @_;
-  unless (ref $obj) {
-    delete $self->{_inflated_column}{$col};
-    return $self->store_column($col, $obj);
+  unless (blessed $obj) {
+      delete $self->{_inflated_column}{$col};
+      $self->store_column($col => $obj);
+      return $obj;
   }
+  delete $self->{_column_data}{$col};
+  return $self->{_inflated_column}{$col} = $obj;
+}
 
-  my $deflated = $self->_deflated_column($col, $obj);
-           # Do this now so we don't store if it's invalid
+=head2 get_column
 
-  $self->{_inflated_column}{$col} = $obj;
-  #warn "Storing $obj: ".($obj->_ident_values)[0];
-  $self->store_column($col, $deflated);
-  return $obj;
+Gets a column value in the same way as L<DBIx::Class::Row/get_column>. If there
+is an inflated value stored that has not yet been deflated, it is deflated
+when the method is invoked.
+
+=cut
+
+sub get_column {
+  my ($self, $col) = @_;
+  if (exists $self->{_inflated_column}{$col}
+        && !exists $self->{_column_data}{$col}) {
+    $self->store_column($col, $self->_deflated_column($col, $self->{_inflated_column}{$col})); 
+  }
+  return $self->next::method($col);
 }
 
-sub new {
+=head2 get_columns 
+
+Returns the get_column info for all columns as a hash,
+just like L<DBIx::Class::Row/get_columns>.  Handles inflation just
+like L</get_column>.
+
+=cut
+
+sub get_columns {
+  my $self = shift;
+  if (exists $self->{_inflated_column}) {
+    foreach my $col (keys %{$self->{_inflated_column}}) {
+      $self->store_column($col, $self->_deflated_column($col, $self->{_inflated_column}{$col}))
+       unless exists $self->{_column_data}{$col};
+    }
+  }
+  return $self->next::method;
+}
+
+=head2 has_column_loaded
+
+Like L<DBIx::Class::Row/has_column_loaded>, but also returns true if there
+is an inflated value stored.
+
+=cut
+
+sub has_column_loaded {
+  my ($self, $col) = @_;
+  return 1 if exists $self->{_inflated_column}{$col};
+  return $self->next::method($col);
+}
+
+=head2 update
+
+Updates a row in the same way as L<DBIx::Class::Row/update>, handling
+inflation and deflation of columns appropriately.
+
+=cut
+
+sub update {
   my ($class, $attrs, @rest) = @_;
-  $attrs ||= {};
-  foreach my $key (keys %$attrs) {
-    if (ref $attrs->{$key}
+  foreach my $key (keys %{$attrs||{}}) {
+    if (ref $attrs->{$key} && $class->has_column($key)
           && exists $class->column_info($key)->{_inflate_info}) {
-      $attrs->{$key} = $class->_deflated_column($key, $attrs->{$key});
+      $class->set_inflated_column($key, delete $attrs->{$key});
     }
   }
   return $class->next::method($attrs, @rest);
 }
 
+=head2 new
+
+Creates a row in the same way as L<DBIx::Class::Row/new>, handling
+inflation and deflation of columns appropriately.
+
+=cut
+
+sub new {
+  my ($class, $attrs, @rest) = @_;
+  my $inflated;
+  foreach my $key (keys %{$attrs||{}}) {
+    $inflated->{$key} = delete $attrs->{$key} 
+      if ref $attrs->{$key} && $class->has_column($key)
+         && exists $class->column_info($key)->{_inflate_info};
+  }
+  my $obj = $class->next::method($attrs, @rest);
+  $obj->{_inflated_column} = $inflated if $inflated;
+  return $obj;
+}
+
+=head1 SEE ALSO
+
+=over 4
+
+=item L<DBIx::Class::Core> - This component is loaded as part of the
+      "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)
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+
+=cut
+
 1;