NAME
SPOPS::Configure::DBI - Define additional configuration methods
SYNOPSIS
my $init_classes = SPOPS::Configure::DBI->parse_config( { config => $CONFIG->{SPOPS} } );DESCRIPTION
We override the method additional_work() from SPOPS::Configure so we can create subroutines in the classes that want to link_to other objects, among other things.
It is possible -- and perhaps desirable for the sake of clarity -- to create a method within SPOPS::DBI that does all the work for us, then we would only need to create a subroutine that calls that subroutine.
However, creating routines with the values embedded directly in them should be quicker and more efficient. So we will try it this way.
METHODS
create_relationship( $spops_config )
Get the config and plow through the SPOPS classes, seeing if any of them have the links_to key defined. If so, we create three subroutines with the proper info.
The first is named '${links_to}' and simply returns an arrayref of objects that the main object links to. For instance:
Example:
# $links_to = 'group'
# Retrieve all groups that this user is a member of
my $group_list = eval { $user->group };The second is named '${links_to}_add' and links the object to any number of other objects. The return value is the number of successful links.
The third is named '${links_to}_remove' and removes links from the object to any number of other objects. The return value is the number of successful removals.
Examples:
# $links_to = 'group'
# First retrieve all groups
my $group_list = eval { $user->group };
print "Group list: ", join( ' // ', map { $_->{group_id} } @{ $group_list } );
>> 2 // 3 // 5
# Now add some more, making the user a member of these new groups
my $added = eval { $user->group_add( [ 7, 9, 21, 23 ] ) };
print "Group list: ", join( ' // ', map { $_->{group_id} } @{ $group_list } );
>> 2 // 3 // 5 // 7 // 9 // 21 // 23
# Now remove two of them
my $removed = eval { $user->group_remove( [ 2, 21 ] ) };
print "Group list: ", join( ' // ', map { $_->{group_id} } @{ $group_list } );
>> 3 // 5 // 7 // 9 // 23CONFIGURATION FIELDS EXPLAINED
links_to (\%)
The 'links_to' field allows you to specify a SPOPS alias and specify which table is used to link the objects:
{
'SPOPS-tag' => 'table_name',
}Note that this relationship assumes a link table that joins two separate tables. When you sever a link between two objects, you are only deleting the link rather than deleting an object. See "TO DO" for another proposal.
We are also considering making 'SPOPS-tag' into 'SPOPS-class' to make this more versatile. See SPOPS::Configure for more info.
TO DO
Make 'links_to' more flexible
We need to account for different types of linking; this may require an additional field beyond 'links_to' that has a similar effect but works differently.
For instance, Table-B might have a 'has_a' relationship with Table-A, but Table-A might have a 'links_to' relationship with Table-B. (Themes in OpenInteract work like this.) We need to be able to specify that when Table-A severs its relationship with one or more objects from Table-B, the actual object is removed rather than just a link between them.
BUGS
COPYRIGHT
Copyright (c) 2000 intes.net, inc.. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
AUTHORS
Chris Winters <chris@cwinters.com>