X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=a33e22f5b80beed3d811447bfee0ed429a5fc28a;hb=8452e496;hp=e8513b2d850e6440124bbdd92980eb942bdc5e6e;hpb=fef5d100c208d604c7a7b3c33eb6e32946d71848;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm
index e8513b2..a33e22f 100644
--- a/lib/DBIx/Class/ResultSet.pm
+++ b/lib/DBIx/Class/ResultSet.pm
@@ -6,94 +6,348 @@ use overload
         '0+'     => 'count',
         fallback => 1;
 use Data::Page;
+use Storable;
+
+=head1 NAME
+
+DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
+
+=head1 SYNOPSIS
+
+my $rs = MyApp::DB::Class->search(registered => 1);
+my @rows = MyApp::DB::Class->search(foo => 'bar');
+
+=head1 DESCRIPTION
+
+The resultset is also known as an iterator. It is responsible for handling
+queries that may return an arbitrary number of rows, e.g. via C<search>
+or a C<has_many> relationship.
+
+=head1 METHODS
+
+=head2 new($source, \%$attrs)
+
+The resultset constructor. Takes a source object (usually a DBIx::Class::Table)
+and an attribute hash (see below for more information on attributes). Does
+not perform any queries -- these are executed as needed by the other methods.
+
+=cut
 
 sub new {
-  my ($it_class, $db_class, $attrs) = @_;
+  my $class = shift;
+  $class->new_result(@_) if ref $class;
+  my ($source, $attrs) = @_;
   #use Data::Dumper; warn Dumper(@_);
-  $it_class = ref $it_class if ref $it_class;
-  $attrs = { %{ $attrs || {} } };
-  if ($attrs->{join}) {
-    $attrs->{from} = [ { 'me' => $db_class->_table_name },
-                         $db_class->_resolve_join($attrs->{join}, 'me') ];
-    $attrs->{cols} = [ map { "me.$_" } $db_class->_select_columns ];
+  $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
+  my %seen;
+  my $alias = ($attrs->{alias} ||= 'me');
+  if (!$attrs->{select}) {
+    my @cols = ($attrs->{cols}
+                 ? @{delete $attrs->{cols}}
+                 : $source->result_class->_select_columns);
+    $attrs->{select} = [ map { m/\./ ? $_ : "${alias}.$_" } @cols ];
+  }
+  $attrs->{as} ||= [ map { m/^$alias\.(.*)$/ ? $1 : $_ } @{$attrs->{select}} ];
+  #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/});
+  $attrs->{from} ||= [ { $alias => $source->from } ];
+  if (my $join = delete $attrs->{join}) {
+    foreach my $j (ref $join eq 'ARRAY'
+              ? (@{$join}) : ($join)) {
+      if (ref $j eq 'HASH') {
+        $seen{$_} = 1 foreach keys %$j;
+      } else {
+        $seen{$j} = 1;
+      }
+    }
+    push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}));
+  }
+  $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
+  foreach my $pre (@{delete $attrs->{prefetch} || []}) {
+    push(@{$attrs->{from}}, $source->resolve_join($pre, $attrs->{alias}))
+      unless $seen{$pre};
+    my @pre = 
+      map { "$pre.$_" }
+      $source->result_class->relationship_info($pre)->{class}->columns;
+    push(@{$attrs->{select}}, @pre);
+    push(@{$attrs->{as}}, @pre);
+  }
+  if ($attrs->{page}) {
+    $attrs->{rows} ||= 10;
+    $attrs->{offset} ||= 0;
+    $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
   }
   my $new = {
-    class => $db_class,
-    cols => $attrs->{cols} || [ $db_class->_select_columns ],
+    source => $source,
     cond => $attrs->{where},
-    from => $attrs->{from} || $db_class->_table_name,
+    from => $attrs->{from},
     count => undef,
+    page => delete $attrs->{page},
     pager => undef,
     attrs => $attrs };
-  bless ($new, $it_class);
-  $new->pager if ($attrs->{page});
+  bless ($new, $class);
   return $new;
 }
 
+=head2 search
+
+  my @obj    = $rs->search({ foo => 3 }); # "... WHERE foo = 3"              
+  my $new_rs = $rs->search({ foo => 3 });                                    
+                                                                                
+If you need to pass in additional attributes but no additional condition,
+call it as ->search(undef, \%attrs);
+                                                                                
+  my @all = $class->search({}, { cols => [qw/foo bar/] }); # "SELECT foo, bar FROM $class_table"
+
+=cut
+
+sub search {
+  my $self = shift;
+
+  #use Data::Dumper;warn Dumper(@_);
+
+  my $attrs = { %{$self->{attrs}} };
+  if (@_ > 1 && ref $_[$#_] eq 'HASH') {
+    $attrs = { %$attrs, %{ pop(@_) } };
+  }
+
+  my $where = (@_ ? ((@_ == 1 || ref $_[0] eq "HASH") ? shift : {@_}) : undef());
+  if (defined $where) {
+    $where = (defined $attrs->{where}
+                ? { '-and' => [ $where, $attrs->{where} ] }
+                : $where);
+    $attrs->{where} = $where;
+  }
+
+  my $rs = (ref $self)->new($self->{source}, $attrs);
+
+  return (wantarray ? $rs->all : $rs);
+}
+
+=head2 search_literal                                                              
+  my @obj    = $rs->search_literal($literal_where_cond, @bind);
+  my $new_rs = $rs->search_literal($literal_where_cond, @bind);
+
+Pass a literal chunk of SQL to be added to the conditional part of the
+resultset
+
+=cut
+                                                         
+sub search_literal {
+  my ($self, $cond, @vals) = @_;
+  my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
+  $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
+  return $self->search(\$cond, $attrs);
+}
+
+=head2 find(@colvalues), find(\%cols)
+
+Finds a row based on its primary key(s).                                        
+
+=cut                                                                            
+
+sub find {
+  my ($self, @vals) = @_;
+  my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {});
+  my @pk = $self->{source}->primary_columns;
+  #use Data::Dumper; warn Dumper($attrs, @vals, @pk);
+  $self->{source}->result_class->throw( "Can't find unless primary columns are defined" )
+    unless @pk;
+  my $query;
+  if (ref $vals[0] eq 'HASH') {
+    $query = $vals[0];
+  } elsif (@pk == @vals) {
+    $query = {};
+    @{$query}{@pk} = @vals;
+  } else {
+    $query = {@vals};
+  }
+  #warn Dumper($query);
+  # Useless -> disabled
+  #$self->{source}->result_class->throw( "Can't find unless all primary keys are specified" )
+  #  unless (keys %$query >= @pk); # If we check 'em we run afoul of uc/lc
+                                  # column names etc. Not sure what to do yet
+  return $self->search($query)->next;
+}
+
+=head2 search_related
+
+  $rs->search_related('relname', $cond?, $attrs?);
+
+=cut
+
+sub search_related {
+  my ($self, $rel, @rest) = @_;
+  my $rel_obj = $self->{source}->result_class->relationship_info($rel);
+  $self->{source}->result_class->throw(
+    "No such relationship ${rel} in search_related")
+      unless $rel_obj;
+  my $rs = $self->search(undef, { join => $rel });
+  return $self->{source}->schema->resultset($rel_obj->{class}
+           )->search( undef,
+             { %{$rs->{attrs}},
+               alias => $rel,
+               select => undef(),
+               as => undef() }
+           )->search(@rest);
+}
+
+=head2 cursor
+
+Returns a storage-driven cursor to the given resultset.
+
+=cut
+
 sub cursor {
   my ($self) = @_;
-  my ($db_class, $attrs) = @{$self}{qw/class attrs/};
-  if ($attrs->{page}) {
-    $attrs->{rows} = $self->pager->entries_per_page;
-    $attrs->{offset} = $self->pager->skipped;
-  }
+  my ($source, $attrs) = @{$self}{qw/source attrs/};
+  $attrs = { %$attrs };
   return $self->{cursor}
-    ||= $db_class->storage->select($self->{from}, $self->{cols},
+    ||= $source->storage->select($self->{from}, $attrs->{select},
           $attrs->{where},$attrs);
 }
 
+=head2 search_like                                                               
+                                                                                
+Identical to search except defaults to 'LIKE' instead of '=' in condition       
+                                                                                
+=cut                                                                            
+
+sub search_like {
+  my $class    = shift;
+  my $attrs = { };
+  if (@_ > 1 && ref $_[$#_] eq 'HASH') {
+    $attrs = pop(@_);
+  }
+  my $query    = ref $_[0] eq "HASH" ? { %{shift()} }: {@_};
+  $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
+  return $class->search($query, { %$attrs });
+}
+
+=head2 slice($first, $last)
+
+Returns a subset of elements from the resultset.
+
+=cut
+
 sub slice {
   my ($self, $min, $max) = @_;
   my $attrs = { %{ $self->{attrs} || {} } };
-  $self->{class}->throw("Can't slice without where") unless $attrs->{where};
-  $attrs->{offset} = $min;
+  $attrs->{offset} ||= 0;
+  $attrs->{offset} += $min;
   $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
-  my $slice = $self->new($self->{class}, $attrs);
+  my $slice = (ref $self)->new($self->{source}, $attrs);
   return (wantarray ? $slice->all : $slice);
 }
 
+=head2 next 
+
+Returns the next element in the resultset (undef is there is none).
+
+=cut
+
 sub next {
   my ($self) = @_;
   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}{as} };
+  #warn "@cols -> @row";
+  my (%me, %pre);
+  foreach my $col (@cols) {
+    if ($col =~ /([^\.]+)\.([^\.]+)/) {
+      $pre{$1}[0]{$2} = shift @row;
+    } else {
+      $me{$col} = shift @row;
+    }
+  }
+  my $new = $self->{source}->result_class->inflate_result(\%me, \%pre);
+  $new = $self->{attrs}{record_filter}->($new)
+    if exists $self->{attrs}{record_filter};
+  return $new;
 }
 
+=head2 count
+
+Performs an SQL C<COUNT> with the same query as the resultset was built
+with to find the number of elements. If passed arguments, does a search
+on the resultset and counts the results of that.
+
+=cut
+
 sub count {
-  my ($self) = @_;
-  my $db_class = $self->{class};
-  my $attrs = { %{ $self->{attrs} } };
-  unless ($self->{count}) {
-    # offset and order by are not needed to count
-    delete $attrs->{$_} for qw/offset order_by/;
+  my $self = shift;
+  return $self->search(@_)->count if @_ && defined $_[0];
+  die "Unable to ->count with a GROUP BY" if defined $self->{attrs}{group_by};
+  unless (defined $self->{count}) {
+    my $attrs = { %{ $self->{attrs} },
+                  select => { 'count' => '*' },
+                  as => [ 'count' ] };
+    # offset, order by and page are not needed to count. record_filter is cdbi
+    delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
         
-    my @cols = 'COUNT(*)';
-    $self->{count} = $db_class->storage->select_single($self->{from}, \@cols,
-                                              $self->{cond}, $attrs);
+    ($self->{count}) = (ref $self)->new($self->{source}, $attrs)->cursor->next;
   }
   return 0 unless $self->{count};
-  return $self->{pager}->entries_on_this_page if ($self->{pager});
-  return ( $attrs->{rows} && $attrs->{rows} < $self->{count} ) 
-    ? $attrs->{rows} 
-    : $self->{count};
+  my $count = $self->{count};
+  $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
+  $count = $self->{attrs}{rows} if
+    ($self->{attrs}{rows} && $self->{attrs}{rows} < $count);
+  return $count;
 }
 
+=head2 count_literal
+
+Calls search_literal with the passed arguments, then count.
+
+=cut
+
+sub count_literal { shift->search_literal(@_)->count; }
+
+=head2 all
+
+Returns all elements in the resultset. Called implictly if the resultset
+is returned in list context.
+
+=cut
+
 sub all {
   my ($self) = @_;
-  return map { $self->{class}->_row_to_object($self->{cols}, $_); }
+  return map { $self->_construct_object(@$_); }
            $self->cursor->all;
 }
 
+=head2 reset
+
+Resets the resultset's cursor, so you can iterate through the elements again.
+
+=cut
+
 sub reset {
   my ($self) = @_;
   $self->cursor->reset;
   return $self;
 }
 
+=head2 first
+
+Resets the resultset and returns the first element.
+
+=cut
+
 sub first {
   return $_[0]->reset->next;
 }
 
+=head2 delete
+
+Deletes all elements in the resultset.
+
+=cut
+
 sub delete {
   my ($self) = @_;
   $_->delete for $self->all;
@@ -102,22 +356,155 @@ sub delete {
 
 *delete_all = \&delete; # Yeah, yeah, yeah ...
 
+=head2 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};
+  die "Can't create pager for non-paged rs" unless $self->{page};
+  $attrs->{rows} ||= 10;
+  $self->count;
+  return $self->{pager} ||= Data::Page->new(
+    $self->{count}, $attrs->{rows}, $self->{page});
 }
 
+=head2 page($page_num)
+
+Returns a new resultset for the specified page.
+
+=cut
+
 sub page {
   my ($self, $page) = @_;
-  my $attrs = $self->{attrs};
+  my $attrs = { %{$self->{attrs}} };
   $attrs->{page} = $page;
-  return $self->new($self->{class}, $attrs);
+  return (ref $self)->new($self->{source}, $attrs);
+}
+
+=head2 new_result(\%vals)
+
+Creates a result in the resultset's result class
+
+=cut
+
+sub new_result {
+  my ($self, $values) = @_;
+  $self->{source}->result_class->throw( "new_result needs a hash" )
+    unless (ref $values eq 'HASH');
+  $self->{source}->result_class->throw( "Can't abstract implicit construct, condition not a hash" )
+    if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
+  my %new = %$values;
+  my $alias = $self->{attrs}{alias};
+  foreach my $key (keys %{$self->{cond}||{}}) {
+    $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:$alias\.)?([^\.]+)$/);
+  }
+  return $self->{source}->result_class->new(\%new);
+}
+
+=head2 create(\%vals)
+
+Inserts a record into the resultset and returns the object
+
+Effectively a shortcut for ->new_result(\%vals)->insert
+
+=cut
+
+sub create {
+  my ($self, $attrs) = @_;
+  $self->{source}->result_class->throw( "create needs a hashref" ) unless ref $attrs eq 'HASH';
+  return $self->new_result($attrs)->insert;
+}
+
+=head2 find_or_create(\%vals)
+
+  $class->find_or_create({ key => $val, ... });                                 
+                                                                                
+Searches for a record matching the search condition; if it doesn't find one,    
+creates one and returns that instead.                                           
+                                                                                
+=cut
+
+sub find_or_create {
+  my $self     = shift;
+  my $hash     = ref $_[0] eq "HASH" ? shift: {@_};
+  my $exists   = $self->find($hash);
+  return defined($exists) ? $exists : $self->create($hash);
 }
 
+=head1 ATTRIBUTES
+
+The resultset takes various attributes that modify its behavior.
+Here's an overview of them:
+
+=head2 order_by
+
+Which column(s) to order the results by. This is currently passed
+through directly to SQL, so you can give e.g. C<foo DESC> for a 
+descending order.
+
+=head2 cols (arrayref)
+
+Shortcut to request a particular set of columns to be retrieved - adds
+'me.' onto the start of any column without a '.' in it and sets 'select'
+from that, then auto-populates 'as' from 'select' as normal
+
+=head2 select (arrayref)
+
+Indicates which columns should be selected from the storage
+
+=head2 as (arrayref)
+
+Indicates column names for object inflation
+
+=head2 join
+
+Contains a list of relationships that should be joined for this query. Can also 
+contain a hash reference to refer to that relation's relations. So, if one column
+in your class C<belongs_to> foo and another C<belongs_to> bar, you can do
+C<< join => [qw/ foo bar /] >> to join both (and e.g. use them for C<order_by>).
+If a foo contains many margles and you want to join those too, you can do
+C<< join => { foo => 'margle' } >>. If you want to fetch the columns from the
+related table as well, see C<prefetch> below.
+
+=head2 prefetch
+
+Contains a list of relationships that should be fetched along with the main 
+query (when they are accessed afterwards they will have already been
+"prefetched"). This is useful for when you know you will need the related
+object(s), because it saves a query. Currently limited to prefetching
+one relationship deep, so unlike C<join>, prefetch must be an arrayref.
+
+=head2 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!
+
+=head2 page
+
+For a paged resultset, specifies which page to retrieve. Leave unset
+for an unpaged resultset.
+
+=head2 rows
+
+For a paged resultset, how many rows per page
+
+=head2 group_by
+
+A list of columns to group by (note that 'count' doesn't work on grouped
+resultsets)
+
+=head2 distinct
+
+Set to 1 to group by all columns
+
+=cut
+
 1;