use strict;
use warnings;
+use base qw/DBIx::Class/;
+
use DBIx::Class::ResultSet;
use DBIx::Class::ResultSourceHandle;
-use Carp::Clan qw/^DBIx::Class/;
-use Storable;
-use base qw/DBIx::Class/;
+use DBIx::Class::Exception;
+use Carp::Clan qw/^DBIx::Class/;
__PACKAGE__->mk_group_accessors('simple' => qw/_ordered_columns
_columns _primaries _unique_constraints name resultset_attributes
- schema from _relationships column_info_from_storage source_info/);
+ schema from _relationships column_info_from_storage source_info
+ source_name sqlt_deploy_callback/);
__PACKAGE__->mk_group_accessors('component_class' => qw/resultset_class
result_class/);
-__PACKAGE__->mk_group_ro_accessors('simple' => qw/source_name/);
-
=head1 NAME
DBIx::Class::ResultSource - Result source object
=head1 SYNOPSIS
+ # Create a table based result source, in a result class.
+
+ package MyDB::Schema::Result::Artist;
+ use base qw/DBIx::Class::Core/;
+
+ __PACKAGE__->table('artist');
+ __PACKAGE__->add_columns(qw/ artistid name /);
+ __PACKAGE__->set_primary_key('artistid');
+ __PACKAGE__->has_many(cds => 'MyDB::Schema::Result::CD');
+
+ 1;
+
+ # Create a query (view) based result source, in a result class
+ package MyDB::Schema::Result::Year2000CDs;
+ use base qw/DBIx::Class::Core/;
+
+ __PACKAGE__->load_components('InflateColumn::DateTime');
+ __PACKAGE__->table_class('DBIx::Class::ResultSource::View');
+
+ __PACKAGE__->table('year2000cds');
+ __PACKAGE__->result_source_instance->is_virtual(1);
+ __PACKAGE__->result_source_instance->view_definition(
+ "SELECT cdid, artist, title FROM cd WHERE year ='2000'"
+ );
+
+
=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>)
+A ResultSource is an object that represents a source of data for querying.
-=head1 METHODS
+This class is a base class for various specialised types of result
+sources, for example L<DBIx::Class::ResultSource::Table>. Table is the
+default result source type, so one is created for you when defining a
+result class as described in the synopsis above.
-=pod
+More specifically, the L<DBIx::Class::Core> base class pulls in the
+L<DBIx::Class::ResultSourceProxy::Table> component, which defines
+the L<table|DBIx::Class::ResultSourceProxy::Table/table> method.
+When called, C<table> creates and stores an instance of
+L<DBIx::Class::ResultSoure::Table>. Luckily, to use tables as result
+sources, you don't need to remember any of this.
-=head2 new
+Result sources representing select queries, or views, can also be
+created, see L<DBIx::Class::ResultSource::View> for full details.
- $class->new();
+=head2 Finding result source objects
- $class->new({attribute_name => value});
+As mentioned above, a result source instance is created and stored for
+you when you define a L<Result Class|DBIx::Class::Manual::Glossary/Result Class>.
-Creates a new ResultSource object. Not normally called directly by end users.
+You can retrieve the result source at runtime in the following ways:
+
+=over
+
+=item From a Schema object:
+
+ $schema->source($source_name);
+
+=item From a Row object:
+
+ $row->result_source;
+
+=item From a ResultSet object:
+
+ $rs->result_source;
+
+=back
+
+=head1 METHODS
+
+=pod
=cut
$new->{_relationships} = { %{$new->{_relationships}||{}} };
$new->{name} ||= "!!NAME NOT SET!!";
$new->{_columns_info_loaded} ||= 0;
+ $new->{sqlt_deploy_callback} ||= "default_sqlt_deploy_hook";
return $new;
}
=pod
-=head2 source_info
+=head2 add_columns
-Stores a hashref of per-source metadata. No specific key names
-have yet been standardized, the examples below are purely hypothetical
-and don't actually accomplish anything on their own:
+=over
- __PACKAGE__->source_info({
- "_tablespace" => 'fast_disk_array_3',
- "_engine" => 'InnoDB',
- });
+=item Arguments: @columns
-=head2 add_columns
+=item Return value: The ResultSource object
+
+=back
+
+ $source->add_columns(qw/col1 col2 col3/);
- $table->add_columns(qw/col1 col2 col3/);
+ $source->add_columns('col1' => \%col1_info, 'col2' => \%col2_info, ...);
- $table->add_columns('col1' => \%col1_info, 'col2' => \%col2_info, ...);
+Adds columns to the result source. If supplied colname => hashref
+pairs, uses the hashref as the L</column_info> for that column. Repeated
+calls of this method will add more columns, not replace them.
-Adds columns to the result source. If supplied key => hashref pairs, uses
-the hashref as the column_info for that column. Repeated calls of this
-method will add more columns, not replace them.
+The column names given will be created as accessor methods on your
+L<DBIx::Class::Row> objects. You can change the name of the accessor
+by supplying an L</accessor> in the column_info hash.
The contents of the column_info are not set in stone. The following
keys are currently recognised/used by DBIx::Class:
=item accessor
-Use this to set the name of the accessor for this column. If unset,
+ { accessor => '_name' }
+
+ # example use, replace standard accessor with one of your own:
+ sub name {
+ my ($self, $value) = @_;
+
+ die "Name cannot contain digits!" if($value =~ /\d/);
+ $self->_name($value);
+
+ return $self->_name();
+ }
+
+Use this to set the name of the accessor method for this column. If unset,
the name of the column will be used.
=item data_type
-This contains the column type. It is automatically filled by the
-L<SQL::Translator::Producer::DBIx::Class::File> producer, and the
-L<DBIx::Class::Schema::Loader> module. If you do not enter a
-data_type, DBIx::Class will attempt to retrieve it from the
-database for you, using L<DBI>'s column_info method. The values of this
-key are typically upper-cased.
+ { data_type => 'integer' }
+
+This contains the column type. It is automatically filled if you use the
+L<SQL::Translator::Producer::DBIx::Class::File> producer, or the
+L<DBIx::Class::Schema::Loader> module.
Currently there is no standard set of values for the data_type. Use
whatever your database supports.
=item size
+ { size => 20 }
+
The length of your column, if it is a column type that can have a size
-restriction. This is currently only used by L<DBIx::Class::Schema/deploy>.
+restriction. This is currently only used to create tables from your
+schema, see L<DBIx::Class::Schema/deploy>.
=item is_nullable
-Set this to a true value for a columns that is allowed to contain
-NULL values. This is currently only used by L<DBIx::Class::Schema/deploy>.
+ { is_nullable => 1 }
+
+Set this to a true value for a columns that is allowed to contain NULL
+values, default is false. This is currently only used to create tables
+from your schema, see L<DBIx::Class::Schema/deploy>.
=item is_auto_increment
+ { is_auto_increment => 1 }
+
Set this to a true value for a column whose value is somehow
-automatically set. This is used to determine which columns to empty
-when cloning objects using C<copy>. It is also used by
+automatically set, defaults to false. This is used to determine which
+columns to empty when cloning objects using
+L<DBIx::Class::Row/copy>. It is also used by
L<DBIx::Class::Schema/deploy>.
+=item is_numeric
+
+ { is_numeric => 1 }
+
+Set this to a true or false value (not C<undef>) to explicitly specify
+if this column contains numeric data. This controls how set_column
+decides whether to consider a column dirty after an update: if
+C<is_numeric> is true a numeric comparison C<< != >> will take place
+instead of the usual C<eq>
+
+If not specified the storage class will attempt to figure this out on
+first access to the column, based on the column C<data_type>. The
+result will be cached in this attribute.
+
=item is_foreign_key
+ { is_foreign_key => 1 }
+
Set this to a true value for a column that contains a key from a
-foreign table. This is currently only used by
-L<DBIx::Class::Schema/deploy>.
+foreign table, defaults to false. This is currently only used to
+create tables from your schema, see L<DBIx::Class::Schema/deploy>.
=item default_value
-Set this to the default value which will be inserted into a column
-by the database. Can contain either a value or a function. This is
-currently only used by L<DBIx::Class::Schema/deploy>.
+ { default_value => \'now()' }
+
+Set this to the default value which will be inserted into a column by
+the database. Can contain either a value or a function (use a
+reference to a scalar e.g. C<\'now()'> if you want a function). This
+is currently only used to create tables from your schema, see
+L<DBIx::Class::Schema/deploy>.
+
+See the note on L<DBIx::Class::Row/new> for more information about possible
+issues related to db-side default values.
=item sequence
+ { sequence => 'my_table_seq' }
+
Set this on a primary key column to the name of the sequence used to
generate a new key value. If not specified, L<DBIx::Class::PK::Auto>
will attempt to retrieve the name of the sequence from the database
automatically.
-=item extras
+=item auto_nextval
+
+Set this to a true value for a column whose value is retrieved automatically
+from a sequence or function (if supported by your Storage driver.) For a
+sequence, if you do not use a trigger to get the nextval, you have to set the
+L</sequence> value as well.
+
+Also set this for MSSQL columns with the 'uniqueidentifier'
+L<DBIx::Class::ResultSource/data_type> whose values you want to automatically
+generate using C<NEWID()>, unless they are a primary key in which case this will
+be done anyway.
+
+=item extra
This is used by L<DBIx::Class::Schema/deploy> and L<SQL::Translator>
-to add extra non-generic data to the column. For example: C<< extras
+to add extra non-generic data to the column. For example: C<< extra
=> { unsigned => 1} >> is used by the MySQL producer to set an integer
column to unsigned. For more details, see
L<SQL::Translator::Producer::MySQL>.
=head2 add_column
- $table->add_column('col' => \%info?);
+=over
-Convenience alias to add_columns.
+=item Arguments: $colname, \%columninfo?
+
+=item Return value: 1/0 (true/false)
+
+=back
+
+ $source->add_column('col' => \%info);
+
+Add a single column and optional column info. Uses the same column
+info keys as L</add_columns>.
=cut
=head2 has_column
- if ($obj->has_column($col)) { ... }
+=over
+
+=item Arguments: $colname
+
+=item Return value: 1/0 (true/false)
+
+=back
+
+ if ($source->has_column($colname)) { ... }
Returns true if the source has a column of this name, false otherwise.
=head2 column_info
- my $info = $obj->column_info($col);
+=over
+
+=item Arguments: $colname
-Returns the column metadata hashref for a column. See the description
-of add_column for information on the contents of the hashref.
+=item Return value: Hashref of info
+
+=back
+
+ my $info = $source->column_info($col);
+
+Returns the column metadata hashref for a column, as originally passed
+to L</add_columns>. See L</add_columns> above for information on the
+contents of the hashref.
=cut
return $self->_columns->{$column};
}
-=head2 column_info_from_storage
+=head2 columns
-Enables the on-demand automatic loading of the above column
-metadata from storage as neccesary. This is *deprecated*, and
-should not be used. It will be removed before 1.0.
+=over
- __PACKAGE__->column_info_from_storage(1);
+=item Arguments: None
-=head2 columns
+=item Return value: Ordered list of column names
- my @column_names = $obj->columns;
+=back
+
+ my @column_names = $source->columns;
-Returns all column names in the order they were declared to add_columns.
+Returns all column names in the order they were declared to L</add_columns>.
=cut
my $self = shift;
$self->throw_exception(
"columns() is a read-only accessor, did you mean add_columns()?"
- ) if (@_ > 1);
+ ) if @_;
return @{$self->{_ordered_columns}||[]};
}
=head2 remove_columns
- $table->remove_columns(qw/col1 col2 col3/);
+=over
-Removes columns from the result source.
+=item Arguments: @colnames
+
+=item Return value: undefined
+
+=back
+
+ $source->remove_columns(qw/col1 col2 col3/);
+
+Removes the given list of columns by name, from the result source.
+
+B<Warning>: Removing a column that is also used in the sources primary
+key, or in one of the sources unique constraints, B<will> result in a
+broken result source.
=head2 remove_column
- $table->remove_column('col');
+=over
-Convenience alias to remove_columns.
+=item Arguments: $colname
-=cut
+=item Return value: undefined
-sub remove_columns {
- my ($self, @cols) = @_;
+=back
- return unless $self->_ordered_columns;
+ $source->remove_column('col');
- my $columns = $self->_columns;
- my @remaining;
+Remove a single column by name from the result source, similar to
+L</remove_columns>.
- foreach my $col (@{$self->_ordered_columns}) {
- push @remaining, $col unless grep(/$col/, @cols);
- }
+B<Warning>: Removing a column that is also used in the sources primary
+key, or in one of the sources unique constraints, B<will> result in a
+broken result source.
+
+=cut
+
+sub remove_columns {
+ my ($self, @to_remove) = @_;
- foreach (@cols) {
+ my $columns = $self->_columns
+ or return;
+
+ my %to_remove;
+ for (@to_remove) {
delete $columns->{$_};
- };
+ ++$to_remove{$_};
+ }
- $self->_ordered_columns(\@remaining);
+ $self->_ordered_columns([ grep { not $to_remove{$_} } @{$self->_ordered_columns} ]);
}
sub remove_column { shift->remove_columns(@_); } # DO NOT CHANGE THIS TO GLOB
=item Arguments: @cols
+=item Return value: undefined
+
=back
-Defines one or more columns as primary key for this source. Should be
-called after C<add_columns>.
+Defines one or more columns as primary key for this source. Must be
+called after L</add_columns>.
-Additionally, defines a unique constraint named C<primary>.
+Additionally, defines a L<unique constraint|add_unique_constraint>
+named C<primary>.
The primary key columns are used by L<DBIx::Class::PK::Auto> to
-retrieve automatically created values from the database.
+retrieve automatically created values from the database. They are also
+used as default joining columns when specifying relationships, see
+L<DBIx::Class::Relationship>.
=cut
=head2 primary_columns
-Read-only accessor which returns the list of primary keys.
+=over 4
+
+=item Arguments: None
+
+=item Return value: Ordered list of primary column names
+
+=back
+
+Read-only accessor which returns the list of primary keys, supplied by
+L</set_primary_key>.
=cut
return @{shift->_primaries||[]};
}
+sub _pri_cols {
+ my $self = shift;
+ my @pcols = $self->primary_columns
+ or $self->throw_exception (sprintf(
+ 'Operation requires a primary key to be declared on %s via set_primary_key',
+ $self->source_name,
+ ));
+ return @pcols;
+}
+
=head2 add_unique_constraint
+=over 4
+
+=item Arguments: $name?, \@colnames
+
+=item Return value: undefined
+
+=back
+
Declare a unique constraint on this source. Call once for each unique
constraint.
__PACKAGE__->add_unique_constraint([ qw/column1 column2/ ]);
-This will result in a unique constraint named C<table_column1_column2>, where
-C<table> is replaced with the table name.
+This will result in a unique constraint named
+C<table_column1_column2>, where C<table> is replaced with the table
+name.
+
+Unique constraints are used, for example, when you pass the constraint
+name as the C<key> attribute to L<DBIx::Class::ResultSet/find>. Then
+only columns in the constraint are searched.
-Unique constraints are used, for example, when you call
-L<DBIx::Class::ResultSet/find>. Only columns in the constraint are searched.
+Throws an error if any of the given column names do not yet exist on
+the result source.
=cut
=head2 name_unique_constraint
-Return a name for a unique constraint containing the specified columns. These
-names consist of the table name and each column name, separated by underscores.
+=over 4
+
+=item Arguments: @colnames
+
+=item Return value: Constraint name
+
+=back
+
+ $source->table('mytable');
+ $source->name_unique_constraint('col1', 'col2');
+ # returns
+ 'mytable_col1_col2'
+
+Return a name for a unique constraint containing the specified
+columns. The name is created by joining the table name and each column
+name, using an underscore character.
For example, a constraint on a table named C<cd> containing the columns
C<artist> and C<title> would result in a constraint name of C<cd_artist_title>.
+This is used by L</add_unique_constraint> if you do not specify the
+optional constraint name.
+
=cut
sub name_unique_constraint {
my ($self, $cols) = @_;
- return join '_', $self->name, @$cols;
+ my $name = $self->name;
+ $name = $$name if (ref $name eq 'SCALAR');
+
+ return join '_', $name, @$cols;
}
=head2 unique_constraints
-Read-only accessor which returns the list of unique constraints on this source.
+=over 4
+
+=item Arguments: None
+
+=item Return value: Hash of unique constraint data
+
+=back
+
+ $source->unique_constraints();
+
+Read-only accessor which returns a hash of unique constraints on this
+source.
+
+The hash is keyed by constraint name, and contains an arrayref of
+column names as values.
=cut
=head2 unique_constraint_names
+=over 4
+
+=item Arguments: None
+
+=item Return value: Unique constraint names
+
+=back
+
+ $source->unique_constraint_names();
+
Returns the list of unique constraint names defined on this source.
=cut
=head2 unique_constraint_columns
+=over 4
+
+=item Arguments: $constraintname
+
+=item Return value: List of constraint columns
+
+=back
+
+ $source->unique_constraint_columns('myconstraint');
+
Returns the list of columns that make up the specified unique constraint.
=cut
return @{ $unique_constraints{$constraint_name} };
}
+=head2 sqlt_deploy_callback
+
+=over
+
+=item Arguments: $callback
+
+=back
+
+ __PACKAGE__->sqlt_deploy_callback('mycallbackmethod');
+
+An accessor to set a callback to be called during deployment of
+the schema via L<DBIx::Class::Schema/create_ddl_dir> or
+L<DBIx::Class::Schema/deploy>.
+
+The callback can be set as either a code reference or the name of a
+method in the current result class.
+
+If not set, the L</default_sqlt_deploy_hook> is called.
+
+Your callback will be passed the $source object representing the
+ResultSource instance being deployed, and the
+L<SQL::Translator::Schema::Table> object being created from it. The
+callback can be used to manipulate the table object or add your own
+customised indexes. If you need to manipulate a non-table object, use
+the L<DBIx::Class::Schema/sqlt_deploy_hook>.
+
+See L<DBIx::Class::Manual::Cookbook/Adding Indexes And Functions To
+Your SQL> for examples.
+
+This sqlt deployment callback can only be used to manipulate
+SQL::Translator objects as they get turned into SQL. To execute
+post-deploy statements which SQL::Translator does not currently
+handle, override L<DBIx::Class::Schema/deploy> in your Schema class
+and call L<dbh_do|DBIx::Class::Storage::DBI/dbh_do>.
+
+=head2 default_sqlt_deploy_hook
+
+=over
+
+=item Arguments: $source, $sqlt_table
+
+=item Return value: undefined
+
+=back
+
+This is the sensible default for L</sqlt_deploy_callback>.
+
+If a method named C<sqlt_deploy_hook> exists in your Result class, it
+will be called and passed the current C<$source> and the
+C<$sqlt_table> being deployed.
+
+=cut
+
+sub default_sqlt_deploy_hook {
+ my $self = shift;
+
+ my $class = $self->result_class;
+
+ if ($class and $class->can('sqlt_deploy_hook')) {
+ $class->sqlt_deploy_hook(@_);
+ }
+}
+
+sub _invoke_sqlt_deploy_hook {
+ my $self = shift;
+ if ( my $hook = $self->sqlt_deploy_callback) {
+ $self->$hook(@_);
+ }
+}
+
+=head2 resultset
+
+=over 4
+
+=item Arguments: None
+
+=item Return value: $resultset
+
+=back
+
+Returns a resultset for the given source. This will initially be created
+on demand by calling
+
+ $self->resultset_class->new($self, $self->resultset_attributes)
+
+but is cached from then on unless resultset_class changes.
+
+=head2 resultset_class
+
+=over 4
+
+=item Arguments: $classname
+
+=item Return value: $classname
+
+=back
+
+ package My::Schema::ResultSet::Artist;
+ use base 'DBIx::Class::ResultSet';
+ ...
+
+ # In the result class
+ __PACKAGE__->resultset_class('My::Schema::ResultSet::Artist');
+
+ # Or in code
+ $source->resultset_class('My::Schema::ResultSet::Artist');
+
+Set the class of the resultset. This is useful if you want to create your
+own resultset methods. Create your own class derived from
+L<DBIx::Class::ResultSet>, and set it here. If called with no arguments,
+this method returns the name of the existing resultset class, if one
+exists.
+
+=head2 resultset_attributes
+
+=over 4
+
+=item Arguments: \%attrs
+
+=item Return value: \%attrs
+
+=back
+
+ # In the result class
+ __PACKAGE__->resultset_attributes({ order_by => [ 'id' ] });
+
+ # Or in code
+ $source->resultset_attributes({ order_by => [ 'id' ] });
+
+Store a collection of resultset attributes, that will be set on every
+L<DBIx::Class::ResultSet> produced from this result source. For a full
+list see L<DBIx::Class::ResultSet/ATTRIBUTES>.
+
+=cut
+
+sub resultset {
+ my $self = shift;
+ $self->throw_exception(
+ 'resultset does not take any arguments. If you want another resultset, '.
+ 'call it on the schema instead.'
+ ) if scalar @_;
+
+ return $self->resultset_class->new(
+ $self,
+ {
+ %{$self->{resultset_attributes}},
+ %{$self->schema->default_resultset_attributes}
+ },
+ );
+}
+
+=head2 source_name
+
+=over 4
+
+=item Arguments: $source_name
+
+=item Result value: $source_name
+
+=back
+
+Set an alternate name for the result source when it is loaded into a schema.
+This is useful if you want to refer to a result source by a name other than
+its class name.
+
+ package ArchivedBooks;
+ use base qw/DBIx::Class/;
+ __PACKAGE__->table('books_archive');
+ __PACKAGE__->source_name('Books');
+
+ # from your schema...
+ $schema->resultset('Books')->find(1);
+
=head2 from
+=over 4
+
+=item Arguments: None
+
+=item Return value: FROM clause
+
+=back
+
+ my $from_clause = $source->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.
=head2 schema
+=over 4
+
+=item Arguments: None
+
+=item Return value: A schema object
+
+=back
+
+ my $schema = $source->schema();
+
Returns the L<DBIx::Class::Schema> object that this result source
-belongs too.
+belongs to.
=head2 storage
+=over 4
+
+=item Arguments: None
+
+=item Return value: A Storage object
+
+=back
+
+ $source->storage->debug(1);
+
Returns the storage handle for the current schema.
See also: L<DBIx::Class::Storage>
-=cut
+=cut
+
+sub storage { shift->schema->storage; }
+
+=head2 add_relationship
+
+=over 4
+
+=item Arguments: $relname, $related_source_name, \%cond, [ \%attrs ]
-sub storage { shift->schema->storage; }
+=item Return value: 1/true if it succeeded
-=head2 add_relationship
+=back
$source->add_relationship('relname', 'related_source', $cond, $attrs);
+L<DBIx::Class::Relationship> describes a series of methods which
+create pre-defined useful types of relationships. Look there first
+before using this method directly.
+
The relationship name can be arbitrary, but must be unique for each
relationship attached to this result source. 'related_source' should
be the name with which the related result source was registered with
The condition C<$cond> needs to be an L<SQL::Abstract>-style
representation of the join between the tables. For example, if you're
-creating a rel from Author to Book,
+creating a relation from Author to Book,
{ 'foreign.author_id' => 'self.id' }
=back
+Throws an exception if the condition is improperly supplied, or cannot
+be resolved.
+
=cut
sub add_relationship {
unless $cond;
$attrs ||= {};
+ # Check foreign and self are right in cond
+ if ( (ref $cond ||'') eq 'HASH') {
+ for (keys %$cond) {
+ $self->throw_exception("Keys of condition should be of form 'foreign.col', not '$_'")
+ if /\./ && !/^foreign\./;
+ }
+ }
+
my %rels = %{ $self->_relationships };
$rels{$rel} = { class => $f_source_name,
source => $f_source_name,
}
return unless $f_source; # Can't test rel without f_source
- eval { $self->resolve_join($rel, 'me') };
+ eval { $self->_resolve_join($rel, 'me', {}, []) };
if ($@) { # If the resolve failed, back out and re-throw the error
delete $rels{$rel}; #
=head2 relationships
+=over 4
+
+=item Arguments: None
+
+=item Return value: List of relationship names
+
+=back
+
+ my @relnames = $source->relationships();
+
Returns all relationship names for this source.
=cut
=item Arguments: $relname
+=item Return value: Hashref of relation data,
+
=back
Returns a hash of relationship information for the specified relationship
-name.
+name. The keys/values are as specified for L</add_relationship>.
=cut
=item Arguments: $rel
+=item Return value: 1/0 (true/false)
+
=back
Returns true if the source has a relationship of this name, false otherwise.
=item Arguments: $relname
+=item Return value: Hashref of relationship data
+
=back
-Returns an array of hash references of relationship information for
-the other side of the specified relationship name.
+Looks through all the relationships on the source this relationship
+points to, looking for one whose condition is the reverse of the
+condition on this relationship.
+
+A common use of this is to find the name of the C<belongs_to> relation
+opposing a C<has_many> relation. For definition of these look in
+L<DBIx::Class::Relationship>.
+
+The returned hashref is keyed by the name of the opposing
+relationship, and contains its data in the same manner as
+L</relationship_info>.
=cut
my $otherrel_info = $othertable->relationship_info($otherrel);
my $back = $othertable->related_source($otherrel);
- next unless $back->name eq $self->name;
+ next unless $back->source_name eq $self->source_name;
my @othertestconds;
my @other_cond = keys(%$othercond);
my @other_refkeys = map {/^\w+\.(\w+)$/} @other_cond;
my @other_keys = map {$othercond->{$_} =~ /^\w+\.(\w+)$/} @other_cond;
- next if (!$self->compare_relationship_keys(\@refkeys, \@other_keys) ||
- !$self->compare_relationship_keys(\@other_refkeys, \@keys));
+ next if (!$self->_compare_relationship_keys(\@refkeys, \@other_keys) ||
+ !$self->_compare_relationship_keys(\@other_refkeys, \@keys));
$ret->{$otherrel} = $otherrel_info;
}
}
return $ret;
}
-=head2 compare_relationship_keys
-
-=over 4
-
-=item Arguments: $keys1, $keys2
-
-=back
-
-Returns true if both sets of keynames are the same, false otherwise.
-
-=cut
-
sub compare_relationship_keys {
+ carp 'compare_relationship_keys is a private method, stop calling it';
+ my $self = shift;
+ $self->_compare_relationship_keys (@_);
+}
+
+# Returns true if both sets of keynames are the same, false otherwise.
+sub _compare_relationship_keys {
my ($self, $keys1, $keys2) = @_;
# Make sure every keys1 is in keys2
return $found;
}
-=head2 resolve_join
-
-=over 4
-
-=item Arguments: $relation
+# Returns the {from} structure used to express JOIN conditions
+sub _resolve_join {
+ my ($self, $join, $alias, $seen, $jpath, $parent_force_left) = @_;
-=back
+ # we need a supplied one, because we do in-place modifications, no returns
+ $self->throw_exception ('You must supply a seen hashref as the 3rd argument to _resolve_join')
+ unless ref $seen eq 'HASH';
-Returns the join structure required for the related result source.
+ $self->throw_exception ('You must supply a joinpath arrayref as the 4th argument to _resolve_join')
+ unless ref $jpath eq 'ARRAY';
-=cut
+ $jpath = [@$jpath]; # copy
-sub resolve_join {
- my ($self, $join, $alias, $seen, $force_left) = @_;
- $seen ||= {};
- $force_left ||= { force => 0 };
- if (ref $join eq 'ARRAY') {
- return map { $self->resolve_join($_, $alias, $seen) } @$join;
- } elsif (ref $join eq 'HASH') {
+ if (not defined $join) {
+ return ();
+ }
+ elsif (ref $join eq 'ARRAY') {
return
map {
- my $as = ($seen->{$_} ? $_.'_'.($seen->{$_}+1) : $_);
- local $force_left->{force};
- (
- $self->resolve_join($_, $alias, $seen, $force_left),
- $self->related_source($_)->resolve_join(
- $join->{$_}, $as, $seen, $force_left
- )
- );
- } keys %$join;
- } elsif (ref $join) {
+ $self->_resolve_join($_, $alias, $seen, $jpath, $parent_force_left);
+ } @$join;
+ }
+ elsif (ref $join eq 'HASH') {
+
+ my @ret;
+ for my $rel (keys %$join) {
+
+ my $rel_info = $self->relationship_info($rel)
+ or $self->throw_exception("No such relationship ${rel}");
+
+ my $force_left = $parent_force_left;
+ $force_left ||= lc($rel_info->{attrs}{join_type}||'') eq 'left';
+
+ # the actual seen value will be incremented by the recursion
+ my $as = $self->storage->relname_to_table_alias(
+ $rel, ($seen->{$rel} && $seen->{$rel} + 1)
+ );
+
+ push @ret, (
+ $self->_resolve_join($rel, $alias, $seen, [@$jpath], $force_left),
+ $self->related_source($rel)->_resolve_join(
+ $join->{$rel}, $as, $seen, [@$jpath, { $rel => $as }], $force_left
+ )
+ );
+ }
+ return @ret;
+
+ }
+ elsif (ref $join) {
$self->throw_exception("No idea how to resolve join reftype ".ref $join);
- } else {
+ }
+ else {
my $count = ++$seen->{$join};
- #use Data::Dumper; warn Dumper($seen);
- my $as = ($count > 1 ? "${join}_${count}" : $join);
- my $rel_info = $self->relationship_info($join);
- $self->throw_exception("No such relationship ${join}") unless $rel_info;
- my $type;
- if ($force_left->{force}) {
- $type = 'left';
- } else {
- $type = $rel_info->{attrs}{join_type} || '';
- $force_left->{force} = 1 if lc($type) eq 'left';
- }
- return [ { $as => $self->related_source($join)->from,
- -join_type => $type },
- $self->resolve_condition($rel_info->{cond}, $as, $alias) ];
+ my $as = $self->storage->relname_to_table_alias(
+ $join, ($count > 1 && $count)
+ );
+
+ my $rel_info = $self->relationship_info($join)
+ or $self->throw_exception("No such relationship ${join}");
+
+ my $rel_src = $self->related_source($join);
+ return [ { $as => $rel_src->from,
+ -source_handle => $rel_src->handle,
+ -join_type => $parent_force_left
+ ? 'left'
+ : $rel_info->{attrs}{join_type}
+ ,
+ -join_path => [@$jpath, { $join => $as } ],
+ -is_single => (
+ $rel_info->{attrs}{accessor}
+ &&
+ List::Util::first { $rel_info->{attrs}{accessor} eq $_ } (qw/single filter/)
+ ),
+ -alias => $as,
+ -relation_chain_depth => $seen->{-relation_chain_depth} || 0,
+ },
+ $self->_resolve_condition($rel_info->{cond}, $as, $alias) ];
}
}
-=head2 resolve_condition
+sub pk_depends_on {
+ carp 'pk_depends_on is a private method, stop calling it';
+ my $self = shift;
+ $self->_pk_depends_on (@_);
+}
-=over 4
+# Determines whether a relation is dependent on an object from this source
+# having already been inserted. Takes the name of the relationship and a
+# hashref of columns of the related object.
+sub _pk_depends_on {
+ my ($self, $relname, $rel_data) = @_;
-=item Arguments: $cond, $as, $alias|$object
+ my $relinfo = $self->relationship_info($relname);
-=back
+ # don't assume things if the relationship direction is specified
+ return $relinfo->{attrs}{is_foreign_key_constraint}
+ if exists ($relinfo->{attrs}{is_foreign_key_constraint});
-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.
+ my $cond = $relinfo->{cond};
+ return 0 unless ref($cond) eq 'HASH';
-=cut
+ # map { foreign.foo => 'self.bar' } to { bar => 'foo' }
+ my $keyhash = { map { my $x = $_; $x =~ s/.*\.//; $x; } reverse %$cond };
+
+ # assume anything that references our PK probably is dependent on us
+ # rather than vice versa, unless the far side is (a) defined or (b)
+ # auto-increment
+ my $rel_source = $self->related_source($relname);
+
+ foreach my $p ($self->primary_columns) {
+ if (exists $keyhash->{$p}) {
+ unless (defined($rel_data->{$keyhash->{$p}})
+ || $rel_source->column_info($keyhash->{$p})
+ ->{is_auto_increment}) {
+ return 0;
+ }
+ }
+ }
+
+ return 1;
+}
sub resolve_condition {
+ carp 'resolve_condition is a private method, stop calling it';
+ my $self = shift;
+ $self->_resolve_condition (@_);
+}
+
+# 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.
+our $UNRESOLVABLE_CONDITION = \ '1 = 0';
+
+sub _resolve_condition {
my ($self, $cond, $as, $for) = @_;
- #warn %$cond;
if (ref $cond eq 'HASH') {
my %ret;
foreach my $k (keys %{$cond}) {
$self->throw_exception("Invalid rel cond val ${v}");
if (ref $for) { # Object
#warn "$self $k $for $v";
+ unless ($for->has_column_loaded($v)) {
+ if ($for->in_storage) {
+ $self->throw_exception(sprintf
+ "Unable to resolve relationship '%s' from object %s: column '%s' not "
+ . 'loaded from storage (or not passed to new() prior to insert()). You '
+ . 'probably need to call ->discard_changes to get the server-side defaults '
+ . 'from the database.',
+ $as,
+ $for,
+ $v,
+ );
+ }
+ return $UNRESOLVABLE_CONDITION;
+ }
$ret{$k} = $for->get_column($v);
+ #$ret{$k} = $for->get_column($v) if $for->has_column_loaded($v);
#warn %ret;
} elsif (!defined $for) { # undef, i.e. "no object"
$ret{$k} = undef;
}
return \%ret;
} elsif (ref $cond eq 'ARRAY') {
- return [ map { $self->resolve_condition($_, $as, $for) } @$cond ];
+ return [ map { $self->_resolve_condition($_, $as, $for) } @$cond ];
} else {
- die("Can't handle this yet :(");
+ die("Can't handle condition $cond yet :(");
}
}
-=head2 resolve_prefetch
-
-=over 4
-
-=item Arguments: hashref/arrayref/scalar
-=back
-
-Accepts one or more relationships for the current source and returns an
-array of column names for each of those relationships. Column names are
-prefixed relative to the current source, in accordance with where they appear
-in the supplied relationships. Examples:
-
- my $source = $schema->resultset('Tag')->source;
- @columns = $source->resolve_prefetch( { cd => 'artist' } );
-
- # @columns =
- #(
- # 'cd.cdid',
- # 'cd.artist',
- # 'cd.title',
- # 'cd.year',
- # 'cd.artist.artistid',
- # 'cd.artist.name'
- #)
-
- @columns = $source->resolve_prefetch( qw[/ cd /] );
-
- # @columns =
- #(
- # 'cd.cdid',
- # 'cd.artist',
- # 'cd.title',
- # 'cd.year'
- #)
-
- $source = $schema->resultset('CD')->source;
- @columns = $source->resolve_prefetch( qw[/ artist producer /] );
-
- # @columns =
- #(
- # 'artist.artistid',
- # 'artist.name',
- # 'producer.producerid',
- # 'producer.name'
- #)
+# Accepts one or more relationships for the current source and returns an
+# array of column names for each of those relationships. Column names are
+# prefixed relative to the current source, in accordance with where they appear
+# in the supplied relationships.
-=cut
+sub _resolve_prefetch {
+ my ($self, $pre, $alias, $alias_map, $order, $pref_path) = @_;
+ $pref_path ||= [];
-sub resolve_prefetch {
- my ($self, $pre, $alias, $seen, $order, $collapse) = @_;
- $seen ||= {};
- #$alias ||= $self->name;
- #warn $alias, Dumper $pre;
- if( ref $pre eq 'ARRAY' ) {
+ if (not defined $pre) {
+ return ();
+ }
+ elsif( ref $pre eq 'ARRAY' ) {
return
- map { $self->resolve_prefetch( $_, $alias, $seen, $order, $collapse ) }
+ map { $self->_resolve_prefetch( $_, $alias, $alias_map, $order, [ @$pref_path ] ) }
@$pre;
}
elsif( ref $pre eq 'HASH' ) {
my @ret =
map {
- $self->resolve_prefetch($_, $alias, $seen, $order, $collapse),
- $self->related_source($_)->resolve_prefetch(
- $pre->{$_}, "${alias}.$_", $seen, $order, $collapse)
+ $self->_resolve_prefetch($_, $alias, $alias_map, $order, [ @$pref_path ] ),
+ $self->related_source($_)->_resolve_prefetch(
+ $pre->{$_}, "${alias}.$_", $alias_map, $order, [ @$pref_path, $_] )
} keys %$pre;
- #die Dumper \@ret;
return @ret;
}
elsif( ref $pre ) {
"don't know how to resolve prefetch reftype ".ref($pre));
}
else {
- my $count = ++$seen->{$pre};
- my $as = ($count > 1 ? "${pre}_${count}" : $pre);
+ my $p = $alias_map;
+ $p = $p->{$_} for (@$pref_path, $pre);
+
+ $self->throw_exception (
+ "Unable to resolve prefetch '$pre' - join alias map does not contain an entry for path: "
+ . join (' -> ', @$pref_path, $pre)
+ ) if (ref $p->{-join_aliases} ne 'ARRAY' or not @{$p->{-join_aliases}} );
+
+ my $as = shift @{$p->{-join_aliases}};
+
my $rel_info = $self->relationship_info( $pre );
$self->throw_exception( $self->name . " has no such relationship '$pre'" )
unless $rel_info;
my $as_prefix = ($alias =~ /^.*?\.(.+)$/ ? $1.'.' : '');
my $rel_source = $self->related_source($pre);
- if (exists $rel_info->{attrs}{accessor}
- && $rel_info->{attrs}{accessor} eq 'multi') {
+ if ($rel_info->{attrs}{accessor} && $rel_info->{attrs}{accessor} eq 'multi') {
$self->throw_exception(
"Can't prefetch has_many ${pre} (join cond too complex)")
unless ref($rel_info->{cond}) eq 'HASH';
+ my $dots = @{[$as_prefix =~ m/\./g]} + 1; # +1 to match the ".${as_prefix}"
+
#my @col = map { (/^self\.(.+)$/ ? ("${as_prefix}.$1") : ()); }
# values %{$rel_info->{cond}};
- $collapse->{".${as_prefix}${pre}"} = [ $rel_source->primary_columns ];
- # action at a distance. prepending the '.' allows simpler code
- # in ResultSet->_collapse_result
my @key = map { (/^foreign\.(.+)$/ ? ($1) : ()); }
keys %{$rel_info->{cond}};
my @ord = (ref($rel_info->{attrs}{order_by}) eq 'ARRAY'
? @{$rel_info->{attrs}{order_by}}
- : (defined $rel_info->{attrs}{order_by}
+
+ : (defined $rel_info->{attrs}{order_by}
? ($rel_info->{attrs}{order_by})
- : ()));
+ : ()
+ ));
push(@$order, map { "${as}.$_" } (@key, @ord));
}
return map { [ "${as}.$_", "${as_prefix}${pre}.$_", ] }
$rel_source->columns;
- #warn $alias, Dumper (\@ret);
- #return @ret;
}
}
-=head2 related_source
+# Takes a selection list and generates a collapse-map representing
+# row-object fold-points. Every relationship is assigned a set of unique,
+# non-nullable columns (which may *not even be* from the same resultset)
+# and the collapser will use this information to correctly distinguish
+# data of individual to-be-row-objects.
+sub _resolve_collapse {
+ my ($self, $as, $as_fq_idx, $rel_chain, $parent_info) = @_;
-=over 4
+ # for comprehensible error messages put ourselves at the head of the relationship chain
+ $rel_chain ||= [ $self->source_name ];
-=item Arguments: $relname
+ # record top-level fully-qualified column index
+ $as_fq_idx ||= { %$as };
-=back
+ my ($my_cols, $rel_cols);
+ for (keys %$as) {
+ if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
+ $rel_cols->{$1}{$2} = 1;
+ }
+ else {
+ $my_cols->{$_} = {}; # important for ||= below
+ }
+ }
-Returns the result source object for the given relationship.
+ my $relinfo;
+ # run through relationships, collect metadata, inject non-left fk-bridges from
+ # *INNER-JOINED* children (if any)
+ for my $rel (keys %$rel_cols) {
+ my $rel_src = $self->related_source ($rel);
+ my $inf = $self->relationship_info ($rel);
+
+ $relinfo->{$rel}{is_single} = $inf->{attrs}{accessor} && $inf->{attrs}{accessor} ne 'multi';
+ $relinfo->{$rel}{is_inner} = ( $inf->{attrs}{join_type} || '' ) !~ /^left/i;
+ $relinfo->{$rel}{rsrc} = $rel_src;
+
+ my $cond = $inf->{cond};
+
+ if (
+ ref $cond eq 'HASH'
+ and
+ keys %$cond
+ and
+ ! List::Util::first { $_ !~ /^foreign\./ } (keys %$cond)
+ and
+ ! List::Util::first { $_ !~ /^self\./ } (values %$cond)
+ ) {
+ for my $f (keys %$cond) {
+ my $s = $cond->{$f};
+ $_ =~ s/^ (?: foreign | self ) \.//x for ($f, $s);
+ $relinfo->{$rel}{fk_map}{$s} = $f;
+
+ $my_cols->{$s} ||= { via_fk => "$rel.$f" } # need to know source from *our* pov
+ if ($relinfo->{$rel}{is_inner} && defined $rel_cols->{$rel}{$f}); # only if it is inner and in fact selected of course
+ }
+ }
+ }
-=cut
+ # if the parent is already defined, assume all of its related FKs are selected
+ # (even if they in fact are NOT in the select list). Keep a record of what we
+ # assumed, and if any such phantom-column becomes part of our own collapser,
+ # throw everything assumed-from-parent away and replace with the collapser of
+ # the parent (whatever it may be)
+ my $assumed_from_parent;
+ unless ($parent_info->{underdefined}) {
+ $assumed_from_parent->{columns} = { map
+ # only add to the list if we do not already select said columns
+ { ! exists $my_cols->{$_} ? ( $_ => 1 ) : () }
+ values %{$parent_info->{rel_condition} || {}}
+ };
+
+ $my_cols->{$_} = { via_collapse => $parent_info->{collapse_on} }
+ for keys %{$assumed_from_parent->{columns}};
+ }
-sub related_source {
- my ($self, $rel) = @_;
- if( !$self->has_relationship( $rel ) ) {
- $self->throw_exception("No such relationship '$rel'");
+ # get colinfo for everything
+ if ($my_cols) {
+ $my_cols->{$_}{colinfo} = (
+ $self->has_column ($_) ? $self->column_info ($_) : undef
+ ) for keys %$my_cols;
}
- return $self->schema->source($self->relationship_info($rel)->{source});
-}
-=head2 related_class
+ my $collapse_map;
+
+ # try to resolve based on our columns (plus already inserted FK bridges)
+ if (
+ $my_cols
+ and
+ my $uset = $self->_unique_column_set ($my_cols)
+ ) {
+ # see if the resulting collapser relies on any implied columns,
+ # and fix stuff up if this is the case
+
+ my $parent_collapser_used;
+
+ if (List::Util::first
+ { exists $assumed_from_parent->{columns}{$_} }
+ keys %$uset
+ ) {
+ # remove implied stuff from the uset, we will inject the equivalent collapser a bit below
+ delete @{$uset}{keys %{$assumed_from_parent->{columns}}};
+ $parent_collapser_used = 1;
+ }
-=over 4
+ $collapse_map->{-collapse_on} = {
+ %{ $parent_collapser_used ? $parent_info->{collapse_on} : {} },
+ (map
+ {
+ my $fqc = join ('.',
+ @{$rel_chain}[1 .. $#$rel_chain],
+ ( $my_cols->{$_}{via_fk} || $_ ),
+ );
-=item Arguments: $relname
+ $fqc => $as_fq_idx->{$fqc};
+ }
+ keys %$uset
+ ),
+ };
+ }
-=back
+ # don't know how to collapse - keep descending down 1:1 chains - if
+ # a related non-LEFT 1:1 is resolvable - its condition will collapse us
+ # too
+ unless ($collapse_map->{-collapse_on}) {
+ my @candidates;
+
+ for my $rel (keys %$relinfo) {
+ next unless ($relinfo->{$rel}{is_single} && $relinfo->{$rel}{is_inner});
+
+ if ( my $rel_collapse = $relinfo->{$rel}{rsrc}->_resolve_collapse (
+ $rel_cols->{$rel},
+ $as_fq_idx,
+ [ @$rel_chain, $rel ],
+ { underdefined => 1 }
+ )) {
+ push @candidates, $rel_collapse->{-collapse_on};
+ }
+ }
-Returns the class name for objects in the given relationship.
+ # get the set with least amount of columns
+ # FIXME - maybe need to implement a data type order as well (i.e. prefer several ints
+ # to a single varchar)
+ if (@candidates) {
+ ($collapse_map->{-collapse_on}) = sort { keys %$a <=> keys %$b } (@candidates);
+ }
+ }
-=cut
+ # Still dont know how to collapse - see if the parent passed us anything
+ # (i.e. reuse collapser over 1:1)
+ unless ($collapse_map->{-collapse_on}) {
+ $collapse_map->{-collapse_on} = $parent_info->{collapse_on}
+ if $parent_info->{collapser_reusable};
+ }
-sub related_class {
- my ($self, $rel) = @_;
- if( !$self->has_relationship( $rel ) ) {
- $self->throw_exception("No such relationship '$rel'");
+
+ # stop descending into children if we were called by a parent for first-pass
+ # and don't despair if nothing was found (there may be other parallel branches
+ # to dive into)
+ if ($parent_info->{underdefined}) {
+ return $collapse_map->{-collapse_on} ? $collapse_map : undef
}
- return $self->schema->class($self->relationship_info($rel)->{source});
+ # nothing down the chain resolved - can't calculate a collapse-map
+ elsif (! $collapse_map->{-collapse_on}) {
+ $self->throw_exception ( sprintf
+ "Unable to calculate a definitive collapse column set for %s%s: fetch more unique non-nullable columns",
+ $self->source_name,
+ @$rel_chain > 1
+ ? sprintf (' (last member of the %s chain)', join ' -> ', @$rel_chain )
+ : ''
+ ,
+ );
+ }
+
+
+ # If we got that far - we are collapsable - GREAT! Now go down all children
+ # a second time, and fill in the rest
+
+ for my $rel (keys %$relinfo) {
+
+ $collapse_map->{$rel} = $relinfo->{$rel}{rsrc}->_resolve_collapse (
+ { map { $_ => 1 } ( keys %{$rel_cols->{$rel}} ) },
+
+ $as_fq_idx,
+
+ [ @$rel_chain, $rel],
+
+ {
+ collapse_on => { %{$collapse_map->{-collapse_on}} },
+
+ rel_condition => $relinfo->{$rel}{fk_map},
+
+ # if this is a 1:1 our own collapser can be used as a collapse-map
+ # (regardless of left or not)
+ collapser_reusable => $relinfo->{$rel}{is_single},
+ },
+ );
+ }
+
+ return $collapse_map;
}
-=head2 resultset
+sub _unique_column_set {
+ my ($self, $cols) = @_;
-Returns a resultset for the given source. This will initially be created
-on demand by calling
+ my %unique = $self->unique_constraints;
- $self->resultset_class->new($self, $self->resultset_attributes)
+ # always prefer the PK first, and then shortest constraints first
+ USET:
+ for my $set (delete $unique{primary}, sort { @$a <=> @$b } (values %unique) ) {
+ next unless $set && @$set;
-but is cached from then on unless resultset_class changes.
+ for (@$set) {
+ next USET unless ($cols->{$_} && $cols->{$_}{colinfo} && !$cols->{$_}{colinfo}{is_nullable} );
+ }
-=head2 resultset_class
+ return { map { $_ => 1 } @$set };
+ }
-` package My::ResultSetClass;
- use base 'DBIx::Class::ResultSet';
- ...
+ return undef;
+}
- $source->resultset_class('My::ResultSet::Class');
+# Takes an arrayref of {as} dbic column aliases and the collapse and select
+# attributes from the same $rs (the slector requirement is a temporary
+# workaround), and returns a coderef capable of:
+# my $me_pref_clps = $coderef->([$rs->cursor->next])
+# Where the $me_pref_clps arrayref is the future argument to
+# ::ResultSet::_collapse_result.
+#
+# $me_pref_clps->[0] is always returned (even if as an empty hash with no
+# rowdata), however branches of related data in $me_pref_clps->[1] may be
+# pruned short of what was originally requested based on {as}, depending
+# on:
+#
+# * If collapse is requested, a definitive collapse map is calculated for
+# every relationship "fold-point", consisting of a set of values (which
+# may not even be contained in the future 'me' of said relationship
+# (for example a cd.artist_id defines the related inner-joined artist)).
+# Thus a definedness check is carried on all collapse-condition values
+# and if at least one is undef it is assumed that we are dealing with a
+# NULLed right-side of a left-join, so we don't return a related data
+# container at all, which implies no related objects
+#
+# * If we are not collapsing, there is no constraint on having a selector
+# uniquely identifying all possible objects, and the user might have very
+# well requested a column that just *happens* to be all NULLs. What we do
+# in this case is fallback to the old behavior (which is a potential FIXME)
+# by always returning a data container, but only filling it with columns
+# IFF at least one of them is defined. This way we do not get an object
+# with a bunch of has_column_loaded to undef, but at the same time do not
+# further relationships based off this "null" object (e.g. in case the user
+# deliberately skipped link-table values). I am pretty sure there are some
+# tests that codify this behavior, need to find the exact testname.
+#
+# For an example of this coderef in action (and to see its guts) look at
+# t/prefetch/_internals.t
+#
+# This is a huge performance win, as we call the same code for
+# every row returned from the db, thus avoiding repeated method
+# lookups when traversing relationships
+#
+# Also since the coderef is completely stateless (the returned structure is
+# always fresh on every new invocation) this is a very good opportunity for
+# memoization if further speed improvements are needed
+#
+# The way we construct this coderef is somewhat fugly, although I am not
+# sure if the string eval is *that* bad of an idea. The alternative is to
+# have a *very* large number of anon coderefs calling each other in a twisty
+# maze, whereas the current result is a nice, smooth, single-pass function.
+# In any case - the output of this thing is meticulously micro-tested, so
+# any sort of rewrite should be relatively easy
+#
+sub _mk_row_parser {
+ my ($self, $as, $with_collapse, $select) = @_;
+
+ my $as_indexed = { map
+ { $as->[$_] => $_ }
+ ( 0 .. $#$as )
+ };
-Set the class of the resultset, this is useful if you want to create your
-own resultset methods. Create your own class derived from
-L<DBIx::Class::ResultSet>, and set it here.
+ # calculate collapse fold-points if needed
+ my $collapse_on = do {
+ # FIXME
+ # only consider real columns (not functions) during collapse resolution
+ # this check shouldn't really be here, as fucktards are not supposed to
+ # alias random crap to existing column names anyway, but still - just in
+ # case (also saves us from select/as mismatches which need fixing as well...)
+
+ my $plain_as = { %$as_indexed };
+ for (keys %$plain_as) {
+ delete $plain_as->{$_} if ref $select->[$plain_as->{$_}];
+ }
+ $self->_resolve_collapse ($plain_as);
-=head2 resultset_attributes
+ } if $with_collapse;
- $source->resultset_attributes({ order_by => [ 'id' ] });
+ my $perl = $self->__visit_as ($as_indexed, $collapse_on);
+ my $cref = eval "sub { $perl }"
+ or die "Oops! _mk_row_parser generated invalid perl:\n$@\n\n$perl\n";
+ return $cref;
+}
-Specify here any attributes you wish to pass to your specialised
-resultset. For a full list of these, please see
-L<DBIx::Class::ResultSet/ATTRIBUTES>.
+{
+ my $visit_as_dumper; # keep our own DD object around so we don't have to fitz with quoting
+
+ sub __visit_as {
+ my ($self, $as, $collapse_on, $known_defined) = @_;
+ $known_defined ||= {};
+
+ # prepopulate the known defined map with our own collapse value positions
+ # the rationale is that if an Artist needs column 0 to be uniquely
+ # identified, and related CDs need columns 0 and 1, by the time we get to
+ # CDs we already know that column 0 is defined (otherwise there would be
+ # no related CDs as there is no Artist in the 1st place). So we use this
+ # index to cut on repetitive defined() checks.
+ $known_defined->{$_}++ for ( values %{$collapse_on->{-collapse_on} || {}} );
+
+ my $my_cols = {};
+ my $rel_cols;
+ for (keys %$as) {
+ if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
+ $rel_cols->{$1}{$2} = $as->{$_};
+ }
+ else {
+ $my_cols->{$_} = $as->{$_};
+ }
+ }
-=cut
+ my @relperl;
+ for my $rel (sort keys %$rel_cols) {
+ my $rel_node = $self->__visit_as($rel_cols->{$rel}, $collapse_on->{$rel}, {%$known_defined} );
+
+ my @null_checks;
+ if ($collapse_on->{$rel}{-collapse_on}) {
+ @null_checks = map
+ { "(! defined '__VALPOS__${_}__')" }
+ ( grep
+ { ! $known_defined->{$_} }
+ ( sort
+ { $a <=> $b }
+ values %{$collapse_on->{$rel}{-collapse_on}}
+ )
+ )
+ ;
+ }
-sub resultset {
- my $self = shift;
- $self->throw_exception(
- 'resultset does not take any arguments. If you want another resultset, '.
- 'call it on the schema instead.'
- ) if scalar @_;
+ if (@null_checks) {
+ push @relperl, sprintf ( '(%s) ? () : ( %s => %s )',
+ join (' || ', @null_checks ),
+ $rel,
+ $rel_node,
+ );
+ }
+ else {
+ push @relperl, "$rel => $rel_node";
+ }
+ }
+ my $rels = @relperl
+ ? sprintf ('{ %s }', join (',', @relperl))
+ : 'undef'
+ ;
+
+ my $me = {
+ map { $_ => "__VALPOS__$my_cols->{$_}__" } (keys %$my_cols)
+ };
+
+ my $clps = [
+ map { "__VALPOS__${_}__" } ( sort { $a <=> $b } (values %{$collapse_on->{-collapse_on}}) )
+ ] if $collapse_on->{-collapse_on};
+
+ # we actually will be producing functional perl code here,
+ # thus no second-guessing of what these globals might have
+ # been set to. DO NOT CHANGE!
+ $visit_as_dumper ||= do {
+ require Data::Dumper;
+ Data::Dumper->new([])
+ ->Purity (1)
+ ->Pad ('')
+ ->Useqq (0)
+ ->Terse (1)
+ ->Quotekeys (1)
+ ->Deepcopy (1)
+ ->Deparse (0)
+ ->Maxdepth (0)
+ ->Indent (0)
+ };
+ for ($me, $clps) {
+ $_ = $visit_as_dumper->Values ([$_])->Dump;
+ }
- return $self->resultset_class->new(
- $self, $self->{resultset_attributes}
- );
+ unless ($collapse_on->{-collapse_on}) { # we are not collapsing, insert a definedness check on 'me'
+ $me = sprintf ( '(%s) ? %s : {}',
+ join (' || ', map { "( defined '__VALPOS__${_}__')" } (sort { $a <=> $b } values %$my_cols) ),
+ $me,
+ );
+ }
+
+ my @rv_list = ($me, $rels, $clps);
+ pop @rv_list while ($rv_list[-1] eq 'undef'); # strip trailing undefs
+
+ # change the quoted placeholders to unquoted alias-references
+ $_ =~ s/ \' __VALPOS__(\d+)__ \' /sprintf ('$_[0][%d]', $1)/gex
+ for grep { defined $_ } @rv_list;
+
+ return sprintf '[%s]', join (',', @rv_list);
+ }
}
-=head2 source_name
+=head2 related_source
=over 4
-=item Arguments: $source_name
+=item Arguments: $relname
+
+=item Return value: $source
=back
-Set the name of the result source when it is loaded into a schema.
-This is usefull if you want to refer to a result source by a name other than
-its class name.
+Returns the result source object for the given relationship.
- package ArchivedBooks;
- use base qw/DBIx::Class/;
- __PACKAGE__->table('books_archive');
- __PACKAGE__->source_name('Books');
+=cut
- # from your schema...
- $schema->resultset('Books')->find(1);
+sub related_source {
+ my ($self, $rel) = @_;
+ if( !$self->has_relationship( $rel ) ) {
+ $self->throw_exception("No such relationship '$rel' on " . $self->source_name);
+ }
+ return $self->schema->source($self->relationship_info($rel)->{source});
+}
+
+=head2 related_class
+
+=over 4
+
+=item Arguments: $relname
+
+=item Return value: $classname
+
+=back
+
+Returns the class name for objects in the given relationship.
+
+=cut
+
+sub related_class {
+ my ($self, $rel) = @_;
+ if( !$self->has_relationship( $rel ) ) {
+ $self->throw_exception("No such relationship '$rel'");
+ }
+ return $self->schema->class($self->relationship_info($rel)->{source});
+}
=head2 handle
=cut
sub handle {
- return new DBIx::Class::ResultSourceHandle({
+ return DBIx::Class::ResultSourceHandle->new({
schema => $_[0]->schema,
source_moniker => $_[0]->source_name
});
sub throw_exception {
my $self = shift;
+
if (defined $self->schema) {
$self->schema->throw_exception(@_);
- } else {
- croak(@_);
+ }
+ else {
+ DBIx::Class::Exception->throw(@_);
}
}
+=head2 source_info
+
+Stores a hashref of per-source metadata. No specific key names
+have yet been standardized, the examples below are purely hypothetical
+and don't actually accomplish anything on their own:
+
+ __PACKAGE__->source_info({
+ "_tablespace" => 'fast_disk_array_3',
+ "_engine" => 'InnoDB',
+ });
+
+=head2 new
+
+ $class->new();
+
+ $class->new({attribute_name => value});
+
+Creates a new ResultSource object. Not normally called directly by end users.
+
+=head2 column_info_from_storage
+
+=over
+
+=item Arguments: 1/0 (default: 0)
+
+=item Return value: 1/0
+
+=back
+
+ __PACKAGE__->column_info_from_storage(1);
+
+Enables the on-demand automatic loading of the above column
+metadata from storage as necessary. This is *deprecated*, and
+should not be used. It will be removed before 1.0.
+
+
=head1 AUTHORS
Matt S. Trout <mst@shadowcatsystems.co.uk>