[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / ResultSource.pm

package DBIx::Class::ResultSource;

use strict;
use warnings;

use DBIx::Class::ResultSet;

use Carp qw/croak/;

use base qw/DBIx::Class/;
__PACKAGE__->load_components(qw/AccessorGroup/);

__PACKAGE__->mk_group_accessors('simple' =>
  qw/_ordered_columns _columns _primaries name resultset_class result_class schema from _relationships/);

=head1 NAME 

DBIx::Class::ResultSource - Result source object

=head1 SYNOPSIS

=head1 DESCRIPTION

A ResultSource is a component of a schema from which results can be directly
retrieved, most usually a table (see L<DBIx::Class::ResultSource::Table>)

=head1 METHODS

=cut

sub new {
  my ($class, $attrs) = @_;
  $class = ref $class if ref $class;
  my $new = bless({ %{$attrs || {}} }, $class);
  $new->{resultset_class} ||= 'DBIx::Class::ResultSet';
  $new->{_ordered_columns} ||= [];
  $new->{_columns} ||= {};
  $new->{_relationships} ||= {};
  $new->{name} ||= "!!NAME NOT SET!!";
  return $new;
}

sub add_columns {
  my ($self, @cols) = @_;
  $self->_ordered_columns( \@cols )
    if !$self->_ordered_columns;
  my @added;
  my $columns = $self->_columns;
  while (my $col = shift @cols) {

    my $column_info = ref $cols[0] ? shift : {};
      # If next entry is { ... } use that for the column info, if not
      # use an empty hashref

    push(@added, $col) unless exists $columns->{$col};

    $columns->{$col} = $column_info;
  }
  push @{ $self->_ordered_columns }, @added;
}

*add_column = \&add_columns;

=head2 add_columns

  $table->add_columns(qw/col1 col2 col3/);

  $table->add_columns('col1' => \%col1_info, 'col2' => \%col2_info, ...);

Adds columns to the result source. If supplied key => hashref pairs uses
the hashref as the column_info for that column.

=head2 add_column

  $table->add_column('col' => \%info?);

Convenience alias to add_columns

=cut

sub resultset {
  my $self = shift;
  return $self->resultset_class->new($self);
}

=head2 has_column

  if ($obj->has_column($col)) { ... }                                           
                                                                                
Returns 1 if the source has a column of this name, 0 otherwise.
                                                                                
=cut                                                                            

sub has_column {
  my ($self, $column) = @_;
  return exists $self->_columns->{$column};
}

=head2 column_info 

  my $info = $obj->column_info($col);                                           

Returns the column metadata hashref for a column.
                                                                                
=cut                                                                            

sub column_info {
  my ($self, $column) = @_;
  croak "No such column $column" unless exists $self->_columns->{$column};
  return $self->_columns->{$column};
}

=head2 columns

  my @column_names = $obj->columns;

Returns all column names in the order they were declared to add_columns
                                                                                
=cut                                                                            

sub columns {
  croak "columns() is a read-only accessor, did you mean add_columns()?" if (@_ > 1);
  return @{shift->{_ordered_columns}||[]};
}

=head2 set_primary_key(@cols)                                                   
                                                                                
Defines one or more columns as primary key for this source. Should be
called after C<add_columns>.
                                                                                
=cut                                                                            

sub set_primary_key {
  my ($self, @cols) = @_;
  # check if primary key columns are valid columns
  for (@cols) {
    $self->throw("No such column $_ on table ".$self->name)
      unless $self->has_column($_);
  }
  $self->_primaries(\@cols);
}

=head2 primary_columns                                                          
                                                                                
Read-only accessor which returns the list of primary keys.
                                                                                
=cut                                                                            

sub primary_columns {
  return @{shift->_primaries||[]};
}

=head2 from

Returns an expression of the source to be supplied to storage to specify
retrieval from this source; in the case of a database the required FROM clause
contents.

=cut

=head2 storage

Returns the storage handle for the current schema

=cut

sub storage { shift->schema->storage; }

=head2 add_relationship

  $source->add_relationship('relname', 'related_source', $cond, $attrs);

The relation name can be arbitrary, but must be unique for each relationship
attached to this result source. 'related_source' should be the name with
which the related result source was registered with the current schema
(for simple schemas this is usally either Some::Namespace::Foo or just Foo)

The condition needs to be an SQL::Abstract-style representation of the join
between the tables. For example, if you're creating a rel from Foo to Bar,

  { 'foreign.foo_id' => 'self.id' }                                             
                                                                                
will result in the JOIN clause                                                  
                                                                                
  foo me JOIN bar bar ON bar.foo_id = me.id                                     
                                                                                
You can specify as many foreign => self mappings as necessary.

Valid attributes are as follows:                                                
                                                                                
=over 4                                                                         
                                                                                
=item join_type                                                                 
                                                                                
Explicitly specifies the type of join to use in the relationship. Any SQL       
join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in the SQL      
command immediately before C<JOIN>.                                             
                                                                                
=item proxy                                                                     
                                                                                
An arrayref containing a list of accessors in the foreign class to proxy in     
the main class. If, for example, you do the following:                          
                                                                                
  __PACKAGE__->might_have(bar => 'Bar', undef, { proxy => qw[/ margle /] });    
                                                                                
Then, assuming Bar has an accessor named margle, you can do:                    
                                                                                
  my $obj = Foo->find(1);                                                       
  $obj->margle(10); # set margle; Bar object is created if it doesn't exist     
                                                                                
=item accessor                                                                  
                                                                                
Specifies the type of accessor that should be created for the relationship.     
Valid values are C<single> (for when there is only a single related object),    
C<multi> (when there can be many), and C<filter> (for when there is a single    
related object, but you also want the relationship accessor to double as        
a column accessor). For C<multi> accessors, an add_to_* method is also          
created, which calls C<create_related> for the relationship.                    
                                                                                
=back

=cut

sub add_relationship {
  my ($self, $rel, $f_source_name, $cond, $attrs) = @_;
  die "Can't create relationship without join condition" unless $cond;
  $attrs ||= {};

  my %rels = %{ $self->_relationships };
  $rels{$rel} = { class => $f_source_name,
                  source => $f_source_name,
                  cond  => $cond,
                  attrs => $attrs };
  $self->_relationships(\%rels);

  return 1;

  # XXX disabled. doesn't work properly currently. skip in tests.

  my $f_source = $self->schema->source($f_source_name);
  unless ($f_source) {
    eval "require $f_source_name;";
    if ($@) {
      die $@ unless $@ =~ /Can't locate/;
    }
    $f_source = $f_source_name->result_source;
    #my $s_class = ref($self->schema);
    #$f_source_name =~ m/^${s_class}::(.*)$/;
    #$self->schema->register_class(($1 || $f_source_name), $f_source_name);
    #$f_source = $self->schema->source($f_source_name);
  }
  return unless $f_source; # Can't test rel without f_source

  eval { $self->resolve_join($rel, 'me') };

  if ($@) { # If the resolve failed, back out and re-throw the error
    delete $rels{$rel}; # 
    $self->_relationships(\%rels);
    die "Error creating relationship $rel: $@";
  }
  1;
}

=head2 relationships()

Returns all valid relationship names for this source

=cut

sub relationships {
  return keys %{shift->_relationships};
}

=head2 relationship_info($relname)

Returns the relationship information for the specified relationship name

=cut

sub relationship_info {
  my ($self, $rel) = @_;
  return $self->_relationships->{$rel};
} 

=head2 has_relationship($rel)

Returns 1 if the source has a relationship of this name, 0 otherwise.
                                                                                
=cut                                                                            

sub has_relationship {
  my ($self, $rel) = @_;
  return exists $self->_relationships->{$rel};
}

=head2 resolve_join($relation)

Returns the join structure required for the related result source

=cut

sub resolve_join {
  my ($self, $join, $alias) = @_;
  if (ref $join eq 'ARRAY') {
    return map { $self->resolve_join($_, $alias) } @$join;
  } elsif (ref $join eq 'HASH') {
    return map { $self->resolve_join($_, $alias),
                 $self->related_source($_)->resolve_join($join->{$_}, $_) }
           keys %$join;
  } elsif (ref $join) {
    die("No idea how to resolve join reftype ".ref $join);
  } else {
    my $rel_info = $self->relationship_info($join);
    die("No such relationship ${join}") unless $rel_info;
    my $type = $rel_info->{attrs}{join_type} || '';
    return [ { $join => $self->related_source($join)->from,
               -join_type => $type },
             $self->resolve_condition($rel_info->{cond}, $join, $alias) ];
  }
}

=head2 resolve_condition($cond, $rel, $alias|$object)

Resolves the passed condition to a concrete query fragment. If given an alias,
returns a join condition; if given an object, inverts that object to produce
a related conditional from that object.

=cut

sub resolve_condition {
  my ($self, $cond, $rel, $for) = @_;
  #warn %$cond;
  if (ref $cond eq 'HASH') {
    my %ret;
    while (my ($k, $v) = each %{$cond}) {
      # XXX should probably check these are valid columns
      $k =~ s/^foreign\.// || die "Invalid rel cond key ${k}";
      $v =~ s/^self\.// || die "Invalid rel cond val ${v}";
      if (ref $for) { # Object
        #warn "$self $k $for $v";
        $ret{$k} = $for->get_column($v);
        #warn %ret;
      } else {
        $ret{"${rel}.${k}"} = "${for}.${v}";
      }
    }
    return \%ret;
  } elsif (ref $cond eq 'ARRAY') {
    return [ map { $self->resolve_condition($_, $rel, $for) } @$cond ];
  } else {
   die("Can't handle this yet :(");
  }
}


=head2 related_source($relname)

Returns the result source for the given relationship

=cut

sub related_source {
  my ($self, $rel) = @_;
  return $self->schema->source($self->relationship_info($rel)->{source});
}

1;

=head1 AUTHORS

Matt S. Trout <mst@shadowcatsystems.co.uk>

=head1 LICENSE

You may distribute this code under the same terms as Perl itself.

=cut
Commit	Line	Data
9c992ba1	1	package DBIx::Class::ResultSource;
	2
	3	use strict;
	4	use warnings;
	5
	6	use DBIx::Class::ResultSet;
	7
	8	use Carp qw/croak/;
	9
	10	use base qw/DBIx::Class/;
	11	__PACKAGE__->load_components(qw/AccessorGroup/);
	12
	13	__PACKAGE__->mk_group_accessors('simple' =>
8452e496	14	qw/_ordered_columns _columns _primaries name resultset_class result_class schema from _relationships/);
9c992ba1	15
	16	=head1 NAME
	17
	18	DBIx::Class::ResultSource - Result source object
	19
	20	=head1 SYNOPSIS
	21
	22	=head1 DESCRIPTION
	23
	24	A ResultSource is a component of a schema from which results can be directly
	25	retrieved, most usually a table (see L<DBIx::Class::ResultSource::Table>)
	26
	27	=head1 METHODS
	28
	29	=cut
	30
	31	sub new {
	32	my ($class, $attrs) = @_;
	33	$class = ref $class if ref $class;
	34	my $new = bless({ %{$attrs \|\| {}} }, $class);
	35	$new->{resultset_class} \|\|= 'DBIx::Class::ResultSet';
571dced3	36	$new->{_ordered_columns} \|\|= [];
9c992ba1	37	$new->{_columns} \|\|= {};
8452e496	38	$new->{_relationships} \|\|= {};
9c992ba1	39	$new->{name} \|\|= "!!NAME NOT SET!!";
	40	return $new;
	41	}
	42
	43	sub add_columns {
	44	my ($self, @cols) = @_;
571dced3	45	$self->_ordered_columns( \@cols )
571dced3	46	if !$self->_ordered_columns;
20518cb4	47	my @added;
20518cb4	48	my $columns = $self->_columns;
9c992ba1	49	while (my $col = shift @cols) {
53509665	50
	51	my $column_info = ref $cols[0] ? shift : {};
	52	# If next entry is { ... } use that for the column info, if not
	53	# use an empty hashref
	54
20518cb4	55	push(@added, $col) unless exists $columns->{$col};
	56
	57	$columns->{$col} = $column_info;
9c992ba1	58	}
20518cb4	59	push @{ $self->_ordered_columns }, @added;
9c992ba1	60	}
	61
	62	*add_column = \&add_columns;
	63
	64	=head2 add_columns
	65
	66	$table->add_columns(qw/col1 col2 col3/);
	67
	68	$table->add_columns('col1' => \%col1_info, 'col2' => \%col2_info, ...);
	69
	70	Adds columns to the result source. If supplied key => hashref pairs uses
	71	the hashref as the column_info for that column.
	72
	73	=head2 add_column
	74
	75	$table->add_column('col' => \%info?);
	76
	77	Convenience alias to add_columns
	78
	79	=cut
	80
	81	sub resultset {
	82	my $self = shift;
	83	return $self->resultset_class->new($self);
	84	}
	85
3842b955	86	=head2 has_column
3842b955	87
9c992ba1	88	if ($obj->has_column($col)) { ... }
	89
	90	Returns 1 if the source has a column of this name, 0 otherwise.
	91
	92	=cut
	93
	94	sub has_column {
	95	my ($self, $column) = @_;
	96	return exists $self->_columns->{$column};
	97	}
	98
	99	=head2 column_info
	100
	101	my $info = $obj->column_info($col);
	102
	103	Returns the column metadata hashref for a column.
	104
	105	=cut
	106
	107	sub column_info {
	108	my ($self, $column) = @_;
	109	croak "No such column $column" unless exists $self->_columns->{$column};
	110	return $self->_columns->{$column};
	111	}
	112
	113	=head2 columns
	114
20518cb4	115	my @column_names = $obj->columns;
	116
	117	Returns all column names in the order they were declared to add_columns
9c992ba1	118
	119	=cut
	120
	121	sub columns {
	122	croak "columns() is a read-only accessor, did you mean add_columns()?" if (@_ > 1);
571dced3	123	return @{shift->{_ordered_columns}\|\|[]};
	124	}
	125
9c992ba1	126	=head2 set_primary_key(@cols)
	127
	128	Defines one or more columns as primary key for this source. Should be
	129	called after C<add_columns>.
	130
	131	=cut
	132
	133	sub set_primary_key {
	134	my ($self, @cols) = @_;
	135	# check if primary key columns are valid columns
	136	for (@cols) {
	137	$self->throw("No such column $_ on table ".$self->name)
	138	unless $self->has_column($_);
	139	}
	140	$self->_primaries(\@cols);
	141	}
	142
	143	=head2 primary_columns
	144
	145	Read-only accessor which returns the list of primary keys.
	146
	147	=cut
	148
	149	sub primary_columns {
	150	return @{shift->_primaries\|\|[]};
	151	}
	152
	153	=head2 from
	154
	155	Returns an expression of the source to be supplied to storage to specify
	156	retrieval from this source; in the case of a database the required FROM clause
	157	contents.
	158
	159	=cut
	160
	161	=head2 storage
	162
	163	Returns the storage handle for the current schema
	164
	165	=cut
	166
	167	sub storage { shift->schema->storage; }
	168
8452e496	169	=head2 add_relationship
	170
	171	$source->add_relationship('relname', 'related_source', $cond, $attrs);
	172
	173	The relation name can be arbitrary, but must be unique for each relationship
	174	attached to this result source. 'related_source' should be the name with
	175	which the related result source was registered with the current schema
	176	(for simple schemas this is usally either Some::Namespace::Foo or just Foo)
	177
	178	The condition needs to be an SQL::Abstract-style representation of the join
	179	between the tables. For example, if you're creating a rel from Foo to Bar,
	180
	181	{ 'foreign.foo_id' => 'self.id' }
	182
	183	will result in the JOIN clause
	184
	185	foo me JOIN bar bar ON bar.foo_id = me.id
	186
	187	You can specify as many foreign => self mappings as necessary.
	188
	189	Valid attributes are as follows:
	190
	191	=over 4
	192
	193	=item join_type
	194
	195	Explicitly specifies the type of join to use in the relationship. Any SQL
	196	join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in the SQL
	197	command immediately before C<JOIN>.
	198
	199	=item proxy
	200
	201	An arrayref containing a list of accessors in the foreign class to proxy in
	202	the main class. If, for example, you do the following:
	203
	204	__PACKAGE__->might_have(bar => 'Bar', undef, { proxy => qw[/ margle /] });
	205
	206	Then, assuming Bar has an accessor named margle, you can do:
	207
	208	my $obj = Foo->find(1);
	209	$obj->margle(10); # set margle; Bar object is created if it doesn't exist
	210
	211	=item accessor
	212
	213	Specifies the type of accessor that should be created for the relationship.
	214	Valid values are C<single> (for when there is only a single related object),
	215	C<multi> (when there can be many), and C<filter> (for when there is a single
	216	related object, but you also want the relationship accessor to double as
	217	a column accessor). For C<multi> accessors, an add_to_* method is also
	218	created, which calls C<create_related> for the relationship.
	219
	220	=back
	221
	222	=cut
	223
	224	sub add_relationship {
	225	my ($self, $rel, $f_source_name, $cond, $attrs) = @_;
	226	die "Can't create relationship without join condition" unless $cond;
	227	$attrs \|\|= {};
87772e46	228
8452e496	229	my %rels = %{ $self->_relationships };
8452e496	230	$rels{$rel} = { class => $f_source_name,
87772e46	231	source => $f_source_name,
8452e496	232	cond => $cond,
	233	attrs => $attrs };
	234	$self->_relationships(\%rels);
	235
87772e46	236	return 1;
87772e46	237
953a18ef	238	# XXX disabled. doesn't work properly currently. skip in tests.
953a18ef	239
8452e496	240	my $f_source = $self->schema->source($f_source_name);
	241	unless ($f_source) {
	242	eval "require $f_source_name;";
	243	if ($@) {
	244	die $@ unless $@ =~ /Can't locate/;
	245	}
	246	$f_source = $f_source_name->result_source;
87772e46	247	#my $s_class = ref($self->schema);
	248	#$f_source_name =~ m/^${s_class}::(.*)$/;
	249	#$self->schema->register_class(($1 \|\| $f_source_name), $f_source_name);
	250	#$f_source = $self->schema->source($f_source_name);
8452e496	251	}
	252	return unless $f_source; # Can't test rel without f_source
	253
	254	eval { $self->resolve_join($rel, 'me') };
	255
	256	if ($@) { # If the resolve failed, back out and re-throw the error
	257	delete $rels{$rel}; #
	258	$self->_relationships(\%rels);
	259	die "Error creating relationship $rel: $@";
	260	}
	261	1;
	262	}
	263
	264	=head2 relationships()
	265
	266	Returns all valid relationship names for this source
	267
	268	=cut
	269
	270	sub relationships {
	271	return keys %{shift->_relationships};
	272	}
	273
	274	=head2 relationship_info($relname)
	275
	276	Returns the relationship information for the specified relationship name
	277
	278	=cut
	279
	280	sub relationship_info {
	281	my ($self, $rel) = @_;
	282	return $self->_relationships->{$rel};
	283	}
	284
953a18ef	285	=head2 has_relationship($rel)
	286
	287	Returns 1 if the source has a relationship of this name, 0 otherwise.
	288
	289	=cut
	290
	291	sub has_relationship {
	292	my ($self, $rel) = @_;
	293	return exists $self->_relationships->{$rel};
	294	}
	295
8452e496	296	=head2 resolve_join($relation)
	297
	298	Returns the join structure required for the related result source
	299
	300	=cut
	301
	302	sub resolve_join {
87772e46	303	my ($self, $join, $alias) = @_;
	304	if (ref $join eq 'ARRAY') {
	305	return map { $self->resolve_join($_, $alias) } @$join;
	306	} elsif (ref $join eq 'HASH') {
	307	return map { $self->resolve_join($_, $alias),
	308	$self->related_source($_)->resolve_join($join->{$_}, $_) }
	309	keys %$join;
	310	} elsif (ref $join) {
	311	die("No idea how to resolve join reftype ".ref $join);
	312	} else {
3842b955	313	my $rel_info = $self->relationship_info($join);
	314	die("No such relationship ${join}") unless $rel_info;
	315	my $type = $rel_info->{attrs}{join_type} \|\| '';
953a18ef	316	return [ { $join => $self->related_source($join)->from,
953a18ef	317	-join_type => $type },
3842b955	318	$self->resolve_condition($rel_info->{cond}, $join, $alias) ];
953a18ef	319	}
	320	}
	321
3842b955	322	=head2 resolve_condition($cond, $rel, $alias\|$object)
953a18ef	323
3842b955	324	Resolves the passed condition to a concrete query fragment. If given an alias,
953a18ef	325	returns a join condition; if given an object, inverts that object to produce
	326	a related conditional from that object.
	327
	328	=cut
	329
	330	sub resolve_condition {
3842b955	331	my ($self, $cond, $rel, $for) = @_;
953a18ef	332	#warn %$cond;
	333	if (ref $cond eq 'HASH') {
	334	my %ret;
	335	while (my ($k, $v) = each %{$cond}) {
	336	# XXX should probably check these are valid columns
3842b955	337	$k =~ s/^foreign\.// \|\| die "Invalid rel cond key ${k}";
3842b955	338	$v =~ s/^self\.// \|\| die "Invalid rel cond val ${v}";
953a18ef	339	if (ref $for) { # Object
3842b955	340	#warn "$self $k $for $v";
	341	$ret{$k} = $for->get_column($v);
	342	#warn %ret;
953a18ef	343	} else {
3842b955	344	$ret{"${rel}.${k}"} = "${for}.${v}";
953a18ef	345	}
953a18ef	346	}
953a18ef	347	return \%ret;
5efe4c79	348	} elsif (ref $cond eq 'ARRAY') {
5efe4c79	349	return [ map { $self->resolve_condition($_, $rel, $for) } @$cond ];
953a18ef	350	} else {
953a18ef	351	die("Can't handle this yet :(");
87772e46	352	}
	353	}
	354
953a18ef	355
87772e46	356	=head2 related_source($relname)
	357
	358	Returns the result source for the given relationship
	359
	360	=cut
	361
	362	sub related_source {
	363	my ($self, $rel) = @_;
	364	return $self->schema->source($self->relationship_info($rel)->{source});
8452e496	365	}
8452e496	366
9c992ba1	367	1;
	368
	369	=head1 AUTHORS
	370
	371	Matt S. Trout <mst@shadowcatsystems.co.uk>
	372
	373	=head1 LICENSE
	374
	375	You may distribute this code under the same terms as Perl itself.
	376
	377	=cut
	378