=head1 NAME
-DBIx::Class::ResultClass::HashRefInflator
+DBIx::Class::ResultClass::HashRefInflator - Get raw hashrefs from a resultset
=head1 SYNOPSIS
- my $rs = $schema->resultset('CD');
+ use DBIx::Class::ResultClass::HashRefInflator;
+ my $rs = $schema->resultset('CD');
$rs->result_class('DBIx::Class::ResultClass::HashRefInflator');
+ 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 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 result 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<< $rs->all >> is used).
-There are two ways of using this class.
+There are two ways of applying this class to a resultset:
=over
=back
+=cut
+
+##############
+# NOTE
+#
+# Generally people use this to gain as much speed as possible. If a new &mk_hash is
+# implemented, it should be benchmarked using the maint/benchmark_hashrefinflator.pl
+# script (in addition to passing all tests of course :)
+
+# This coderef is a simple recursive function
+# Arguments: ($me, $prefetch, $is_root) from inflate_result() below
+my $mk_hash;
+$mk_hash = sub {
+
+ 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 { $_ => (
+
+ # null-branch or not
+ ref $_[1]->{$_} eq $DBIx::Class::ResultSource::RowParser::Util::null_branch_class
+
+ ? ref $_[1]->{$_}[0] eq 'ARRAY' ? [] : undef
+
+ : ref $_[1]->{$_}[0] eq 'ARRAY'
+ ? [ map { $mk_hash->( @$_ ) || () } @{$_[1]->{$_}} ]
+ : $mk_hash->( @{$_[1]->{$_}} )
+
+ ) } ($_[1] ? keys %{$_[1]} : ())
+ };
+
+ ($_[2] || keys %$hash) ? $hash : undef;
+};
+
=head1 METHODS
=head2 inflate_result
-Inflates the result and prefetched data into a hash-ref using L<mk_hash>.
+Inflates the result and prefetched data into a hash-ref (invoked by L<DBIx::Class::ResultSet>)
=cut
+##################################################################################
+# inflate_result is invoked as:
+# HRI->inflate_result ($resultsource_instance, $main_data_hashref, $prefetch_data_hashref)
sub inflate_result {
- my ($self, $source, $me, $prefetch) = @_;
-
- return mk_hash($me, $prefetch);
+ return $mk_hash->($_[2], $_[3], 'is_root');
}
-=head2 mk_hash
+1;
-This does all the work of inflating the (pre)fetched data.
+__END__
-=cut
+=head1 CAVEATS
-sub mk_hash {
- my ($me, $rest) = @_;
-
- # $me is the hashref of cols/data from the immediate resultsource
- # $rest is a deep hashref of all the data from the prefetched
- # related sources.
-
- # to avoid emtpy has_many rels contain one empty hashref
- return undef if (not keys %$me);
-
- my $def;
-
- foreach (values %$me) {
- if (defined $_) {
- $def = 1;
- last;
- }
- }
- return undef unless $def;
-
- return { %$me,
- map {
- ( $_ =>
- ref($rest->{$_}[0]) eq 'ARRAY'
- ? [ grep defined, map mk_hash(@$_), @{$rest->{$_}} ]
- : mk_hash( @{$rest->{$_}} )
- )
- } keys %$rest
- };
-}
+=over
-=head1 CAVEAT
+=item *
This will not work for relationships that have been prefetched. Consider the
following:
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.
-=cut
+=item *
-1;
+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
+
+=head1 FURTHER QUESTIONS?
+
+Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.
+
+=head1 COPYRIGHT AND LICENSE
+
+This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE>
+by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can
+redistribute it and/or modify it under the same terms as the
+L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>.
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