=head1 SYNOPSIS
+ use DBIx::Class::ResultClass::HashRefInflator;
+
my $rs = $schema->resultset('CD');
$rs->result_class('DBIx::Class::ResultClass::HashRefInflator');
+ or
+ $rs->result_class(DBIx::Class::ResultClass::HashRefInflator->new (%args));
+
+ while (my $hashref = $rs->next) {
+ ...
+ }
=head1 DESCRIPTION
-DBIx::Class is not built for speed: it's built for convenience and
-ease of use. But sometimes you just need to get the data, and skip the
-fancy objects. That is what this class provides.
+DBIx::Class is faster than older ORMs like Class::DBI but it still isn't
+designed primarily for speed. Sometimes you need to quickly retrieve the data
+from a massive resultset, while skipping the creation of fancy row objects.
+Specifying this class as a C<result_class> for a resultset will change C<< $rs->next >>
+to return a plain data hash-ref (or a list of such hash-refs if C<< $rs->all >> is used).
-There are two ways of using this class.
+There are two ways of using this class:
=over
=item *
-Specify C<< $rs->result_class >> on a specific resultset to affect only that
-resultset (and any chained off of it); or
+Supply an instance of DBIx::Class::ResultClass::HashRefInflator to
+C<< $rs->result_class >>. See L</ARGUMENTS> for a list of valid
+arguments to new().
=item *
-Specify C<< __PACKAGE__->result_class >> on your source object to force all
-uses of that result source to be inflated to hash-refs - this approach is not
-recommended.
+Another way is to simply supply the class name as a string to
+C<< $rs->result_class >>. Equivalent to passing
+DBIx::Class::ResultClass::HashRefInflator->new().
=back
-=head1 AUTOMATICALLY INFLATING COLUMN VALUES
-
-So you want to skip the DBIx::Class object creation part, but you still want
-all your data to be inflated according to the rules you defined in your table
-classes. Setting the global variable
-C<$DBIx::Class::ResultClass::HashRefInflator::inflate_data> to a true value
-will instruct L<mk_hash> to interrogate the processed columns and apply any
-inflation methods declared via L<DBIx::Class::InflateColumn/inflate_column>.
-
-For increased speed the inflation method lookups are cached in
-C<%DBIx::Class::ResultClass::HashRefInflator::inflator_cache>. Make sure to
-reset this hash if you modify column inflators at run time.
+There are two ways of applying this class to a resultset:
-=head1 METHODS
-
-=head2 inflate_result
-
-Inflates the result and prefetched data into a hash-ref using L<mk_hash>.
+=over
-=cut
+=item *
-sub inflate_result {
- my ($self, $source, $me, $prefetch) = @_;
+Specify C<< $rs->result_class >> on a specific resultset to affect only that
+resultset (and any chained off of it); or
- my $hashref = mk_hash($me, $prefetch);
- return $hashref;
-}
+=item *
-=head2 mk_hash
+Specify C<< __PACKAGE__->result_class >> on your source object to force all
+uses of that result source to be inflated to hash-refs - this approach is not
+recommended.
-This does all the work of inflating the (pre)fetched data.
+=back
=cut
##############
# NOTE
#
-# Generally people use this to gain as much speed as possible. If a new mk_hash is
+# Generally people use this to gain as much speed as possible. If a new &mk_hash is
# implemented, it should be benchmarked using the maint/benchmark_hashrefinflator.pl
-# script (in addition to passing all tests of course :). Additional instructions are
+# script (in addition to passing all tests of course :). Additional instructions are
# provided in the script itself.
#
-sub mk_hash {
+# This coderef is a simple recursive function
+# Arguments: ($me, $prefetch) from inflate_result() below
+my $mk_hash;
+$mk_hash = sub {
if (ref $_[0] eq 'ARRAY') { # multi relationship
- return [ map { mk_hash (@$_) || () } (@_) ];
+ return [ map { $mk_hash->(@$_) || () } (@_) ];
}
else {
my $hash = {
# the second arg is a hash of arrays for each prefetched relation
map
- { $_ => mk_hash( @{$_[1]->{$_}} ) }
+ { $_ => $mk_hash->( @{$_[1]->{$_}} ) }
( $_[1] ? (keys %{$_[1]}) : () )
};
return undef;
}
+};
+
+# This is the inflator
+my $inflate_hash;
+$inflate_hash = sub {
+ my ($hri_instance, $schema, $rc, $data) = @_;
+
+ foreach my $column (keys %{$data}) {
+
+ if (ref $data->{$column} eq 'HASH') {
+ $inflate_hash->($hri_instance, $schema, $schema->source ($rc)->related_class ($column), $data->{$column});
+ }
+ elsif (ref $data->{$column} eq 'ARRAY') {
+ foreach my $rel (@{$data->{$column}}) {
+ $inflate_hash->($hri_instance, $schema, $schema->source ($rc)->related_class ($column), $rel);
+ }
+ }
+ else {
+ # "null is null is null"
+ next if not defined $data->{$column};
+
+ # cache the inflator coderef
+ unless (exists $hri_instance->{_inflator_cache}{$rc}{$column}) {
+ $hri_instance->{_inflator_cache}{$rc}{$column} = exists $schema->source ($rc)->_relationships->{$column}
+ ? undef # currently no way to inflate a column sharing a name with a rel
+ : $rc->column_info($column)->{_inflate_info}{inflate}
+ ;
+ }
+
+ if ($hri_instance->{_inflator_cache}{$rc}{$column}) {
+ $data->{$column} = $hri_instance->{_inflator_cache}{$rc}{$column}->($data->{$column});
+ }
+ }
+ }
+};
+
+
+=head1 METHODS
+
+=head2 new
+
+ $class->new( %args );
+ $class->new({ %args });
+
+Creates a new DBIx::Class::ResultClass::HashRefInflator object. Takes the following
+arguments:
+
+=over
+
+=item inflate_columns
+
+Sometimes you still want all your data to be inflated to the corresponding
+objects according to the rules you defined in your table classes (e.g. you
+want all dates in the resulting hash to be replaced with the equivalent
+DateTime objects). Supplying C<< inflate_columns => 1 >> to the constructor will
+interrogate the processed columns and apply any inflation methods declared
+via L<DBIx::Class::InflateColumn/inflate_column> to the contents of the
+resulting hash-ref.
+
+=back
+
+=cut
+
+sub new {
+ my $self = shift;
+ my $args = { (ref $_[0] eq 'HASH') ? %{$_[0]} : @_ };
+ return bless ($args, $self)
+}
+
+=head2 inflate_result
+
+Inflates the result and prefetched data into a hash-ref (invoked by L<DBIx::Class::ResultSet>)
+
+=cut
+
+
+sub inflate_result {
+ my ($self, $source, $me, $prefetch) = @_;
+
+ my $hashref = $mk_hash->($me, $prefetch);
+
+ # if $self is an instance and inflate_columns is set
+ if ( (ref $self) and $self->{inflate_columns} ) {
+ $inflate_hash->($self, $source->schema, $source->result_class, $hashref);
+ }
+
+ return $hashref;
}
-=head1 CAVEAT
+
+=head1 CAVEATS
+
+=over
+
+=item *
This will not work for relationships that have been prefetched. Consider the
following:
HashRefInflator only affects resultsets at inflation time, and prefetch causes
relations to be inflated when the master C<$artist> row is inflated.
+=item *
+
+When using C<inflate_columns>, the inflation method lookups are cached in the
+HashRefInflator object for additional speed. If you modify column inflators at run
+time, make sure to grab a new instance of this class to avoid cached surprises.
+
+=back
+
=cut
1;
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