phpman > perldoc > Class::DBI::Relationship(3pm)

NAME
    Class::DBI::Relationship - base class for Relationships

DESCRIPTION
    A Class::DBI class represents a database table. But merely being able to represent single tables
    isn't really that useful - databases are all about relationships.

    So, Class::DBI provides a variety of Relationship models to represent common database occurences
    (HasA, HasMany and MightHave), and provides a way to add others.

SUBCLASSING
    Relationships should inherit from Class::DBI::Relationship, and provide a variety of methods to
    represent the relationship. For examples of how these are used see
    Class::DBI::Relationship::HasA, Class::DBI::Relationship::HasMany and
    Class::DBI::Relationship::MightHave.

  remap_arguments
            sub remap_arguments {
                    my $self = shift;
                    # process @_;
                    return ($class, accessor, $foreign_class, $args)
            }

    Subclasses should define a 'remap_arguments' method that takes the arguments with which your
    relationship method will be called, and transforms them into the structure that the Relationship
    modules requires. If this method is not provided, then it is assumed that your method will be
    called with these 3 arguments in this order.

    This should return a list of 4 items:

    class
        The Class::DBI subclass to which this relationship applies. This will be passed in to you
        from the caller who actually set up the relationship, and is available for you to call
        methods on whilst performing this mapping. You should almost never need to change this.

        This usually an entire application base class (or Class::DBI itself), but could be a single
        class wishing to override a default relationship.

    accessor
        The method in the class which will provide access to the results of the relationship.

    foreign_class
        The class for the table with which the class has a relationship.

    args
        Any additional args that your relationship requires. It is recommended that you use this as
        a hashref to store any extra information your relationship needs rather than adding extra
        accessors, as this information will all be stored in the 'meta_info'.

  triggers
            sub triggers {
                    return (
                            before_create => sub { ... },
                            after_create  => sub { ... },
                    );
            }

    Subclasses may define a 'triggers' method that returns a list of triggers that the relationship
    needs. This method can be omitted if there are no triggers to be set up.

  methods
            sub methods {
                    return (
                            method1 => sub { ... },
                            method2 => sub { ... },
                    );
            }

    Subclasses may define a 'methods' method that returns a list of methods to facilitate the
    relationship that should be created in the calling Class::DBI class. This method can be omitted
    if there are no methods to be set up.