X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultClass%2FHashRefInflator.pm;h=6d019ad83cc5441811d9d2b888858e81fb5eac84;hb=26283ee38f220f6c6bae720ea5a189c9c0f47f6f;hp=945bcfdc58d5425d9dcf1e252b6a08fa1c54e9f2;hpb=4613ee1e805f722e186dff43738ab63603890b87;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/ResultClass/HashRefInflator.pm b/lib/DBIx/Class/ResultClass/HashRefInflator.pm
index 945bcfd..6d019ad 100644
--- a/lib/DBIx/Class/ResultClass/HashRefInflator.pm
+++ b/lib/DBIx/Class/ResultClass/HashRefInflator.pm
@@ -5,21 +5,27 @@ use warnings;
 
 =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) {
+    ...
+ }
 
 =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 applying this class to a resultset:
 
 =over
 
@@ -36,52 +42,23 @@ recommended.
 
 =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<$DBIx::Class::ResultClass::HashRefInflator::inflate_data> to a true value
-will instruct L<mk_hash> to interrogate the processed columns and apply any
-inflation methods declared via L<DBIx::Class::InflateColumn/inflate_column>.
-
-For increased speed the inflation method lookups are cached in 
-C<%DBIx::Class::ResultClass::HashRefInflator::inflator_cache>. Make sure to 
-reset this hash if you modify column inflators at run time.
-
-=head1 METHODS
-
-=head2 inflate_result
-
-Inflates the result and prefetched data into a hash-ref using L<mk_hash>.
-
-=cut
-
-sub inflate_result {
-    my ($self, $source, $me, $prefetch) = @_;
-
-    my $hashref = mk_hash($me, $prefetch);
-    return $hashref;
-}
-
-=head2 mk_hash
-
-This does all the work of inflating the (pre)fetched data.
-
 =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 = {
@@ -90,21 +67,48 @@ sub mk_hash {
 
             # the second arg is a hash of arrays for each prefetched relation
             map
-                { $_ => mk_hash( @{$_[1]->{$_}} ) }
+                { $_ => $mk_hash->( @{$_[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)
+        # an empty arrayref is an empty multi-sub-prefetch - don't consider
+        # those either
         for (values %$hash) {
-            return $hash if defined $_;
+            if (ref $_ eq 'ARRAY') {
+              return $hash if @$_;
+            }
+            elsif (defined $_) {
+              return $hash;
+            }
         }
 
         return undef;
     }
+};
+
+=head1 METHODS
+
+=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 {
+    return $mk_hash->($_[2], $_[3]);
 }
 
-=head1 CAVEAT
+
+=head1 CAVEATS
+
+=over
+
+=item *
 
 This will not work for relationships that have been prefetched. Consider the
 following:
@@ -119,6 +123,14 @@ 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 *
+
+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
+
 =cut
 
 1;