Additional data in the updates hashref

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!

Treatment of belongs_to relations

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

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

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

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 },
    );

recursive_update

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