use overload
'0+' => 'count',
fallback => 1;
+use Data::Page;
+
+=head1 NAME
+
+DBIX::Class::Recordset - Responsible for fetching and creating recordsets.
+
+=head1 SYNOPSIS;
+
+$rs=MyApp::DB::Class->search(registered=>1);
+
+=head1 DESCRIPTION
+
+The recordset is also know as an iterator.
+
+=head1 METHODS
+
+=over 4
+
+=item new <db_class> <attrs>
+
+The recordset constructor. Takes a db class and an
+attribute hash (see below for more info on attributes)
+
+=cut
sub new {
my ($it_class, $db_class, $attrs) = @_;
#use Data::Dumper; warn Dumper(@_);
$it_class = ref $it_class if ref $it_class;
$attrs = { %{ $attrs || {} } };
- my $cols = [ $db_class->_select_columns ];
- my $cursor = $db_class->storage->select($db_class->_table_name,$cols,
- $attrs->{where},$attrs);
+ my %seen;
+ $attrs->{cols} ||= [ map { "me.$_" } $db_class->_select_columns ];
+ $attrs->{from} ||= [ { 'me' => $db_class->_table_name } ];
+ if ($attrs->{join}) {
+ foreach my $j (ref $attrs->{join} eq 'ARRAY'
+ ? (@{$attrs->{join}}) : ($attrs->{join})) {
+ if (ref $j eq 'HASH') {
+ $seen{$_} = 1 foreach keys %$j;
+ } else {
+ $seen{$j} = 1;
+ }
+ }
+ push(@{$attrs->{from}}, $db_class->_resolve_join($attrs->{join}, 'me'));
+ }
+ foreach my $pre (@{$attrs->{prefetch} || []}) {
+ push(@{$attrs->{from}}, $db_class->_resolve_join($pre, 'me'))
+ unless $seen{$pre};
+ push(@{$attrs->{cols}},
+ map { "$pre.$_" }
+ $db_class->_relationships->{$pre}->{class}->_select_columns);
+ }
my $new = {
class => $db_class,
- cursor => $cursor,
- cols => $cols,
+ cols => $attrs->{cols} || [ $db_class->_select_columns ],
cond => $attrs->{where},
+ from => $attrs->{from} || $db_class->_table_name,
+ count => undef,
+ pager => undef,
attrs => $attrs };
- return bless ($new, $it_class);
+ bless ($new, $it_class);
+ $new->pager if ($attrs->{page});
+ return $new;
}
+=item cursor
+
+Return a storage driven cursor to the given record set.
+
+=cut
+
+sub cursor {
+ my ($self) = @_;
+ my ($db_class, $attrs) = @{$self}{qw/class attrs/};
+ if ($attrs->{page}) {
+ $attrs->{rows} = $self->pager->entries_per_page;
+ $attrs->{offset} = $self->pager->skipped;
+ }
+ return $self->{cursor}
+ ||= $db_class->storage->select($self->{from}, $self->{cols},
+ $attrs->{where},$attrs);
+}
+
+=item slice <first> <last>
+
+return a number of elements from the given record set.
+
+=cut
+
sub slice {
my ($self, $min, $max) = @_;
my $attrs = { %{ $self->{attrs} || {} } };
return (wantarray ? $slice->all : $slice);
}
+=item next
+
+Returns the next element in this record set.
+
+=cut
+
sub next {
my ($self) = @_;
- my @row = $self->{cursor}->next;
+ my @row = $self->cursor->next;
return unless (@row);
- return $self->{class}->_row_to_object($self->{cols}, \@row);
+ return $self->_construct_object(@row);
+}
+
+sub _construct_object {
+ my ($self, @row) = @_;
+ my @cols = @{ $self->{attrs}{cols} };
+ s/^me\.// for @cols;
+ @cols = grep { ! /\./ } @cols;
+ my $new;
+ unless ($self->{attrs}{prefetch}) {
+ $new = $self->{class}->_row_to_object(\@cols, \@row);
+ } else {
+ my @main = splice(@row, 0, scalar @cols);
+ $new = $self->{class}->_row_to_object(\@cols, \@main);
+ PRE: foreach my $pre (@{$self->{attrs}{prefetch}}) {
+ my $rel_obj = $self->{class}->_relationships->{$pre};
+ my $pre_class = $self->{class}->resolve_class($rel_obj->{class});
+ my @pre_cols = $pre_class->_select_columns;
+ my @vals = splice(@row, 0, scalar @pre_cols);
+ my $fetched = $pre_class->_row_to_object(\@pre_cols, \@vals);
+ $self->{class}->throw("No accessor for prefetched $pre")
+ unless defined $rel_obj->{attrs}{accessor};
+ if ($rel_obj->{attrs}{accessor} eq 'single') {
+ foreach my $pri ($rel_obj->{class}->primary_columns) {
+ unless (defined $fetched->get_column($pri)) {
+ undef $fetched;
+ last;
+ }
+ }
+ $new->{_relationship_data}{$pre} = $fetched;
+ } elsif ($rel_obj->{attrs}{accessor} eq 'filter') {
+ $new->{_inflated_column}{$pre} = $fetched;
+ } else {
+ $self->{class}->throw("Don't know how to store prefetched $pre");
+ }
+ }
+ }
+ $new = $self->{attrs}{record_filter}->($new)
+ if exists $self->{attrs}{record_filter};
+ return $new;
}
+=item count
+
+Performs an SQL count with the same query as the resultset was built
+with to find the number of elements.
+
+=cut
+
+
sub count {
my ($self) = @_;
my $db_class = $self->{class};
-
- # offset breaks COUNT(*), so remove it
my $attrs = { %{ $self->{attrs} } };
- delete $attrs->{offset};
-
- my @cols = 'COUNT(*)';
- my ($c) = $db_class->storage->select_single($db_class->_table_name, \@cols,
- $self->{cond}, $attrs);
- return 0 unless $c;
- return ( $attrs->{rows} && $attrs->{rows} < $c )
+ unless ($self->{count}) {
+ # offset and order by are not needed to count
+ delete $attrs->{$_} for qw/offset order_by/;
+
+ my @cols = 'COUNT(*)';
+ $self->{count} = $db_class->storage->select_single($self->{from}, \@cols,
+ $self->{cond}, $attrs);
+ }
+ return 0 unless $self->{count};
+ return $self->{pager}->entries_on_this_page if ($self->{pager});
+ return ( $attrs->{rows} && $attrs->{rows} < $self->{count} )
? $attrs->{rows}
- : $c;
+ : $self->{count};
}
+=item all
+
+Returns all elements in the recordset. Is called implictly if the search
+method is used in list context.
+
+=cut
+
sub all {
my ($self) = @_;
- return map { $self->{class}->_row_to_object($self->{cols}, $_); }
- $self->{cursor}->all;
+ return map { $self->_construct_object(@$_); }
+ $self->cursor->all;
}
+=item reset
+
+Reset this recordset's cursor, so you can iterate through the elements again.
+
+=cut
+
sub reset {
my ($self) = @_;
- $self->{cursor}->reset;
+ $self->cursor->reset;
return $self;
}
+=item first
+
+resets the recordset and returns the first element.
+
+=cut
+
sub first {
return $_[0]->reset->next;
}
+=item delete
+
+Deletes all elements in the recordset.
+
+=cut
+
sub delete {
my ($self) = @_;
$_->delete for $self->all;
*delete_all = \&delete; # Yeah, yeah, yeah ...
+=item pager
+
+Returns a L<Data::Page> object for the current resultset. Only makes
+sense for queries with page turned on.
+
+=cut
+
+sub pager {
+ my ($self) = @_;
+ my $attrs = $self->{attrs};
+ delete $attrs->{offset};
+ my $rows_per_page = delete $attrs->{rows} || 10;
+ $self->{pager} ||= Data::Page->new(
+ $self->count, $rows_per_page, $attrs->{page} || 1);
+ $attrs->{rows} = $rows_per_page;
+ return $self->{pager};
+}
+
+=item page <page>
+
+Returns a new recordset representing a given page.
+
+=cut
+
+sub page {
+ my ($self, $page) = @_;
+ my $attrs = $self->{attrs};
+ $attrs->{page} = $page;
+ return $self->new($self->{class}, $attrs);
+}
+
+=back
+
+=head1 Attributes
+
+The recordset is responsible for handling the various attributes that
+can be passed in with the search functions. Here's an overview of them:
+
+=over 4
+
+=item order_by
+
+Which column to order the results by.
+
+=item cols
+
+Which cols should be retrieved on the first search.
+
+=item join
+
+Contains a list of relations that should be joined for this query. Can also
+contain a hash referece to refer to that relation's relations.
+
+=item from
+
+This attribute can contain a arrayref of elements. each element can be another
+arrayref, to nest joins, or it can be a hash which represents the two sides
+of the join.
+
+*NOTE* Use this on your own risk. This allows you to shoot your foot off!
+
+=item page
+
+Should the resultset be paged? This can also be enabled by using the
+'page' option.
+
+=item rows
+
+For paged resultsset, how many rows per page
+
+=item offset
+
+For paged resultsset, which page to start on.
+
+=back
+
1;
projects / dbsrgits/DBIx-Class.git / blobdiff