Hello, I found an interesting ER diagram on the "Module: ActiveRecord::Associations::ClassMethods" page of the Rails Framework Documentation : http://ar.rubyonrails.org/classes/ActiveRecord/Ass... At the beginning we can read Â« Associations are a set of macro-like class methods for tying objects together through foreign keys. They express relationships like "Project has one Project Manager" or "Project belongs to a Portfolio". Â». I would like to learn more about that concept of expressing relationships between objects. I only knew it as a design concept and can't remember seeing it applied "as this" in the source code using macros. I find the idea interesting. Is it some kind of Ruby "Best Practices" or design/development pattern ? JM. PS : Note that the diagram is not displayed on the "official" page : http://api.rubyonrails.org/classes/ActiveRecord/As... I was only able to find it on that "mirror".
on 2006-05-17 14:06
on 2006-05-17 14:09
Sorry for posting a "truncated" message but it was originally posted on Usenet and I forgot to rewrite it.
on 2006-06-09 11:01
Jean-Marc Molina wrote: > At the beginning we can read Â« Associations are a set of macro-like > class methods for tying objects together through foreign keys. They > express relationships like "Project has one Project Manager" or > "Project belongs to a Portfolio". Â». Reading the "Simplify Business Logic with PHP DataObjects" ONLamp.com article by Darryl Patterson I found an interesting comment about the Class::DBI  Perl module : Â« The greatest part about it is that you can declare relationships between classes/tables by indicating that a certain column in your table either is a foreign key (has_a) or that your table's primary key is referenced from another one (has_many). All the joins will then happen behind the scenes and you can use simple accessors to navigate your relations. Â». The same terms as in the diagram are used : "has_one", "has_many"... I know these are common software design terms but I'm pretty sure it's not a coÃ¯ncidence. I'm about to investigate on Perl communities, stay tuned... JM. Notes : *  <http://www.onlamp.com/pub/a/php/2004/08/05/dataobj... *  <http://www.class-dbi.com>