[Openinteract-dev] Review of proposed changes and a question

[Vsevolod (S. I. <si...@cs...>]

Chris and Ray,

Now that Chris has some time (hopefully) to consider the changes, I'd 
like to submit a patch that would add has_many, auto-save/auto-delete 
(optional) and full cache support (which is necessary for the 
consistency circular references). Before I do that, I'd like to get 
Chris's approval on the following architectural decisions:

1. There will be a basic cache which will always return the cached 
object, not its copy.
2. The fetch_many() now will also use cache. It will still make a call 
to the database, because it won't know which ids to request from the 
cache, though.
3. Auto-save and auto-delete are off by default. This is not what Ray 
requested, but it's the only way to stay backwards compatible. With 
auto-save on, the graph of object in memory will be traversed to 
determine what has been changed. (Thus, I have deep_changed() instead of 
changed().)
4. It will be possible to use a separate class that corresponds to the 
linking table in links_to (think ClubMembership). The syntax I came up 
with is:
  Club => {
     class        => 'Club',
     ...
     links_to        =>
       { 'Person' =>
             { table         => 'ClubMembership',
             link_class => 'ClubMembership',
             link_class_alias => 'memberships',
             alias => 'members',
             to_id_field   => 'member_id',
             from_id_field => 'club_id' },

The ClubMembership class can have extra attributes (like date), but they 
will be specified in a regular way in the config file. The new attribute 
'link_class_alias' will return an arrayref of the ClubMembership 
instances. Again, this is not as elegant as Ray proposed, but backwards 
compatible.

An open question is what to do with has_a. Currently it's implemented in 
ClassFactory, not ClassFactory/DBI, but adding auto-save and auto-delete 
functionality requires the has_a code to be DBI-aware. I can add extra 
functionality into ClassFactory/DBI, but I am not sure which effect it 
would have on LDAP storage, for example.

Oh, and a style question. I have marked all of my changes with "tags":
#Simon
#/Simon
and I commented out, not deleted, all replaced code, for ease of 
reference. Is this necessary?

I will grudgingly remove lc-ing of field names. I love it, but, as 
pointed out before, it will break existing code.

Simon
-- 

Simon (Vsevolod ILyushchenko)   si...@cs...
				http://www.simonf.com

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is equivalent to Roosevelt's declaring war on blitzkrieg.

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