=head1 NAME
-DBIx::Class::ResultClass::HashRefInflator
+DBIx::Class::ResultClass::HashRefInflator - Get raw hashrefs from a resultset
=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) {
+ ...
+ }
+ OR as an attribute:
+
+ my $rs = $schema->resultset('CD')->search({}, {
+ result_class => 'DBIx::Class::ResultClass::HashRefInflator',
+ });
while (my $hashref = $rs->next) {
- ...
+ ...
}
=head1 DESCRIPTION
-DBIx::Class is faster than older ORMs like Class::DBI but it still isn't
+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:
-
-=over
-
-=item *
-
-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 *
-
-Another way is to simply supply the class name as a string to
-C<< $rs->result_class >>. Equivalent to passing
-DBIx::Class::ResultClass::HashRefInflator->new().
-
-=back
-
There are two ways of applying this class to a resultset:
=over
#
# Generally people use this to gain as much speed as possible. If a new &mk_hash is
# implemented, it should be benchmarked using the maint/benchmark_hashrefinflator.pl
-# script (in addition to passing all tests of course :). Additional instructions are
-# provided in the script itself.
-#
+# script (in addition to passing all tests of course :)
# This coderef is a simple recursive function
-# Arguments: ($me, $prefetch) from inflate_result() below
+# Arguments: ($me, $prefetch, $is_root) from inflate_result() below
my $mk_hash;
$mk_hash = sub {
- if (ref $_[0] eq 'ARRAY') { # multi relationship
- return [ map { $mk_hash->(@$_) || () } (@_) ];
- }
- else {
- my $hash = {
- # the main hash could be an undef if we are processing a skipped-over join
- $_[0] ? %{$_[0]} : (),
-
- # the second arg is a hash of arrays for each prefetched relation
- map
- { $_ => $mk_hash->( @{$_[1]->{$_}} ) }
- ( $_[1] ? (keys %{$_[1]}) : () )
- };
-
- # if there is at least one defined column consider the resultset real
- # (and not an emtpy has_many rel containing one empty hashref)
- for (values %$hash) {
- return $hash if defined $_;
- }
-
- 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});
- }
- }
- }
+ my $hash = {
+ # the main hash could be an undef if we are processing a skipped-over join
+ $_[0] ? %{$_[0]} : (),
+
+ # the second arg is a hash of arrays for each prefetched relation
+ map {
+ ref $_[1]->{$_}[0] eq 'ARRAY' # multi rel or not?
+ ? ( $_ => [ map
+ { $mk_hash->(@$_) || () }
+ @{$_[1]->{$_}}
+ ] )
+ : ( $_ => $mk_hash->( @{$_[1]->{$_}} ) )
+
+ } ( $_[1] ? ( keys %{$_[1]} ) : () )
+ };
+
+ # if there is at least one defined column *OR* we are at the root of
+ # the resultset - consider the result real (and not an emtpy has_many
+ # rel containing one empty hashref)
+ # an empty arrayref is an empty multi-sub-prefetch - don't consider
+ # those either
+ return $hash if $_[2];
+
+ for (values %$hash) {
+ return $hash if (
+ defined $_
+ and
+ (ref $_ ne 'ARRAY' or scalar @$_)
+ );
+ }
+
+ return undef;
};
-
=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, $self)
-}
-
=head2 inflate_result
Inflates the result and prefetched data into a hash-ref (invoked by L<DBIx::Class::ResultSet>)
=cut
-
+##################################################################################
+# inflate_result is invoked as:
+# HRI->inflate_result ($resultsource_instance, $main_data_hashref, $prefetch_data_hashref)
sub inflate_result {
- my ($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;
+ return $mk_hash->($_[2], $_[3], 'is_root');
}
my $cds = $artist->cds;
$cds->result_class('DBIx::Class::ResultClass::HashRefInflator');
- my $first = $cds->first;
+ my $first = $cds->first;
-C<$first> will B<not> be a hashref, it will be a normal CD row since
+C<$first> will B<not> be a hashref, it will be a normal CD row since
HashRefInflator only affects resultsets at inflation time, and prefetch causes
relations to be inflated when the master C<$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.
+Column value inflation, e.g., using modules like
+L<DBIx::Class::InflateColumn::DateTime>, is not performed.
+The returned hash contains the raw database values.
=back
projects / dbsrgits/DBIx-Class.git / blobdiff