Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
DBIx::Class::ResultSetUsercContributedIPerClass::ResultSet::RecursiveUpdate(3)

NAME
       DBIx::Class::ResultSet::RecursiveUpdate - like update_or_create - but
       recursive

VERSION
       version 0.34

SYNOPSIS
	   # The functional interface:

	   my $schema =	MyDB::Schema->connect();
	   my $new_item	= DBIx::Class::ResultSet::RecursiveUpdate::Functions::recursive_update(
	       resultset => $schema->resultset('User'),
	       updates => {
		   id => 1,
		   owned_dvds => [
		       {
			   title => "One Flew Over the Cuckoo's	Nest"
		       }
		   ]
	       },
	       unknown_params_ok => 1,
	   );

	   # As	ResultSet subclass:

	   __PACKAGE__->load_namespaces( default_resultset_class => '+DBIx::Class::ResultSet::RecursiveUpdate' );

	   # in	the Schema file	(see t/lib/DBSchema.pm).  Or appropriate 'use base' in the ResultSet classes.

	   my $user = $schema->resultset('User')->recursive_update({
	       id => 1,
	       owned_dvds => [
		   {
		       title =>	"One Flew Over the Cuckoo's Nest"
		   }
	       ]
	   }, {
	       unknown_params_ok => 1,
	   });

	   # You'll get	a warning if you pass non-result specific data to
	   # recursive_update. See L</"Additional data in the updates hashref">
	   # for more information how to prevent this.

DESCRIPTION
       You can feed the	->create method	of DBIx::Class with a recursive
       datastructure and have the related records created. Unfortunately you
       cannot do a similar thing with update_or_create.	This module tries to
       fill that void until DBIx::Class	has an api itself.

       The functional interface	can be used without modifications of the
       model, for example by form processors like
       HTML::FormHandler::Model::DBIC.

       It is a base class for DBIx::Class::ResultSets providing	the method
       recursive_update	which works just like update_or_create but can
       recursively update or create result objects composed of multiple	rows.
       All rows	need to	be identified by primary keys so you need to provide
       them in the update structure (unless they can be	deduced	from the
       parent row. For example a related row of	a belongs_to relationship). If
       any of the primary key columns are missing, a new row will be created,
       with the	expectation that the missing columns will be filled by it (as
       in the case of auto_increment primary keys).

       If the resultset	itself stores an assignment for	the primary key, like
       in the case of:

	   my $restricted_rs = $user_rs->search( { id => 1 } );

       you need	to inform recursive_update about the additional	predicate with
       the fixed_fields	attribute:

	   my $user = $restricted_rs->recursive_update(	{
		   owned_dvds => [
		   {
		       title =>	'One Flew Over the Cuckoo's Nest'
		   }
		   ]
	       },
	       {
		   fixed_fields	=> [ 'id' ],
	       }
	   );

       For a many_to_many (pseudo) relation you	can supply a list of primary
       keys from the other table and it	will link the record at	hand to	those
       and only	those records identified by them. This is convenient for
       handling	web forms with check boxes (or a select	field with multiple
       choice) that lets you update such (pseudo) relations.

       For a description how to	set up base classes for	ResultSets see
       "load_namespaces" in DBIx::Class::Schema.

   Additional data in the updates hashref
       If you pass additional data to recursive_update which doesn't match a
       column name, column accessor, relationship or many-to-many helper
       accessor, it will throw a warning by default. To	disable	this behaviour
       you can set the unknown_params_ok attribute to a	true value.

       The warning thrown is: "No such column, relationship, many-to-many
       helper accessor or generic accessor '$key'"

       When used by HTML::FormHandler::Model::DBIC this	can happen if you have
       additional form fields that aren't relevant to the database but don't
       have the	noupdate attribute set to a true value.

       NOTE: in	a future version this behaviour	will change and	throw an
       exception instead of a warning!

DESIGN CHOICES
       Columns and relationships which are excluded from the updates hashref
       aren't touched at all.

   Treatment of	belongs_to relations
       In case the relationship	is included but	undefined in the updates
       hashref,	all columns forming the	relationship will be set to null.  If
       not all of them are nullable, DBIx::Class will throw an error.

       Updating	the relationship:

	   my $dvd = $dvd_rs->recursive_update(	{
	       id    =>	1,
	       owner =>	$user->id,
	   });

       Clearing	the relationship (only works if	cols are nullable!):

	   my $dvd = $dvd_rs->recursive_update(	{
	       id    =>	1,
	       owner =>	undef,
	   });

       Updating	a relationship including its (full) primary key:

	   my $dvd = $dvd_rs->recursive_update(	{
	       id    =>	1,
	       owner =>	{
		   id	=> 2,
		   name	=> "George",
	       },
	   });

   Treatment of	might_have relationships
       In case the relationship	is included but	undefined in the updates
       hashref,	all columns forming the	relationship will be set to null.

       Updating	the relationship:

	   my $user = $user_rs->recursive_update( {
	       id => 1,
	       address => {
		   street => "101 Main Street",
		   city	  => "Podunk",
		   state  => "New York",
	       }
	   });

       Clearing	the relationship:

	   my $user = $user_rs->recursive_update( {
	       id => 1,
	       address => undef,
	   });

   Treatment of	has_many relations
       If a relationship key is	included in the	data structure with a value of
       undef or	an empty array,	all existing related rows will be deleted, or
       their foreign key columns will be set to	null.

       The exact behaviour depends on the nullability of the foreign key
       columns and the value of	the "if_not_submitted" parameter. The
       parameter defaults to undefined which neither nullifies nor deletes.

       When the	array contains elements	they are updated if they exist,
       created when not	and deleted if not included.

       All foreign table columns are nullable

       In this case recursive_update defaults to nullifying the	foreign
       columns.

       Not all foreign table columns are nullable

       In this case recursive_update deletes the foreign rows.

       Updating	the relationship:

	   Passing ids:

	   my $user = $user_rs->recursive_update( {
	       id	  => 1,
	       owned_dvds => [1, 2],
	   });

	   Passing hashrefs:

	   my $user = $user_rs->recursive_update( {
	       id	  => 1,
	       owned_dvds => [
		   {
		       name => 'temp name 1',
		   },
		   {
		       name => 'temp name 2',
		   },
	       ],
	   });

	   Passing objects:

	   my $user = $user_rs->recursive_update( {
	       id	  => 1,
	       owned_dvds => [ $dvd1, $dvd2 ],
	   });

	   You can even	mix them:

	   my $user = $user_rs->recursive_update( {
	       id	  => 1,
	       owned_dvds => [ 1, { id => 2 } ],
	   });

       Clearing	the relationship:

	   my $user = $user_rs->recursive_update( {
	       id	  => 1,
	       owned_dvds => undef,
	   });

	   This	is the same as passing an empty	array:

	   my $user = $user_rs->recursive_update( {
	       id	  => 1,
	       owned_dvds => [],
	   });

   Treatment of	many-to-many pseudo relations
       If a many-to-many accessor key is included in the data structure	with a
       value of	undef or an empty array, all existing related rows are
       unlinked.

       When the	array contains elements	they are updated if they exist,
       created when not	and deleted if not included.

       RecursiveUpdate defaults	to calling 'set_$rel' to update	many-to-many
       relationships.  See "many_to_many" in DBIx::Class::Relationship for
       details.	 set_$rel effectively removes and re-adds all relationship
       data, even if the set of	related	items did not change at	all.

       If DBIx::Class::IntrospectableM2M is in use, RecursiveUpdate will look
       up the corresponding has_many relationship and use this to recursively
       update the many-to-many relationship.

       While both mechanisms have the same final result, deleting and re-
       adding all relationship data can	have unwanted consequences if triggers
       or method modifiers are defined or logging modules like
       DBIx::Class::AuditLog are in use.

       The traditional "set_$rel" behaviour can	be forced by passing
       "m2m_force_set_rel => 1"	to recursive_update.

       See "is_m2m" for	many-to-many pseudo relationship detection.

       Updating	the relationship:

	   Passing ids:

	   my $dvd = $dvd_rs->recursive_update(	{
	       id   => 1,
	       tags => [1, 2],
	   });

	   Passing hashrefs:

	   my $dvd = $dvd_rs->recursive_update(	{
	       id   => 1,
	       tags => [
		   {
		       id   => 1,
		       file => 'file0'
		   },
		   {
		       id   => 2,
		       file => 'file1',
		   },
	       ],
	   });

	   Passing objects:

	   my $dvd = $dvd_rs->recursive_update(	{
	       id   => 1,
	       tags => [ $tag1,	$tag2 ],
	   });

	   You can even	mix them:

	   my $dvd = $dvd_rs->recursive_update(	{
	       id   => 1,
	       tags => [ 2, { id => 3 }	],
	   });

       Clearing	the relationship:

	   my $dvd = $dvd_rs->recursive_update(	{
	       id   => 1,
	       tags => undef,
	   });

	   This	is the same as passing an empty	array:

	   my $dvd = $dvd_rs->recursive_update(	{
	       id   => 1,
	       tags => [],
	   });

       Make sure that set_$rel used to update many-to-many relationships even
       if IntrospectableM2M is loaded:

	   my $dvd = $dvd_rs->recursive_update(	{
	       id   => 1,
	       tags => [1, 2],
	   },
	   { m2m_force_set_rel => 1 },
	   );

INTERFACE
METHODS
   recursive_update
       The method that does the	work here.

   is_m2m
       Arguments: $name
       Return Value: true, if $name is a many to many pseudo-relationship

       The function gets the information about m2m relations from
       DBIx::Class::IntrospectableM2M. If it isn't loaded in the ResultSource
       class, the code relies on the fact:

	   if($object->can($name) and
		    !$object->result_source->has_relationship($name) and
		    $object->can( 'set_' . $name )
		)

       to identify a many to many pseudo relationship. In a similar ugly way
       the ResultSource	of that	many to	many pseudo relationship is detected.

       So if you need many to many pseudo relationship support,	it's strongly
       recommended to load DBIx::Class::IntrospectableM2M in your ResultSource
       class!

   get_m2m_source
       Arguments: $name
       Return Value: $result_source

CONFIGURATION AND ENVIRONMENT
       DBIx::Class::RecursiveUpdate requires no	configuration files or
       environment variables.

DEPENDENCIES
	   DBIx::Class

       optional	but recommended:
	   DBIx::Class::IntrospectableM2M

INCOMPATIBILITIES
       None reported.

BUGS AND LIMITATIONS
       The list	of reported bugs can be	viewed at
       <http://rt.cpan.org/Public/Dist/Display.html?Name=DBIx-Class-ResultSet-RecursiveUpdate>.

       Please report any bugs or feature requests to
       "bug-DBIx-Class-ResultSet-RecursiveUpdate@rt.cpan.org", or through the
       web interface at	<http://rt.cpan.org>.

AUTHORS
       o   Zbigniew Lukasiak <zby@cpan.org>

       o   John	Napiorkowski <jjnapiork@cpan.org>

       o   Alexander Hartmaier <abraxxa@cpan.org>

       o   Gerda Shank <gshank@cpan.org>

COPYRIGHT AND LICENSE
       This software is	copyright (c) 2013 by Zbigniew Lukasiak, John
       Napiorkowski, Alexander Hartmaier.

       This is free software; you can redistribute it and/or modify it under
       the same	terms as the Perl 5 programming	language system	itself.

perl v5.24.1			  20DBIx::Class::ResultSet::RecursiveUpdate(3)

NAME | VERSION | SYNOPSIS | DESCRIPTION | DESIGN CHOICES | INTERFACE | METHODS | CONFIGURATION AND ENVIRONMENT | DEPENDENCIES | INCOMPATIBILITIES | BUGS AND LIMITATIONS | AUTHORS | COPYRIGHT AND LICENSE

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=DBIx::Class::ResultSet::RecursiveUpdate&sektion=3&manpath=FreeBSD+12.1-RELEASE+and+Ports>

home | help