Hi,
On Sep 30, 2008, at 1:25 PM, Matt S Trout wrote:
On Mon, Sep 29, 2008 at 05:39:25PM +0100, Pedro Melo wrote:
On Sep 29, 2008, at 4:50 PM, Matt S Trout wrote:
On Sun, Sep 28, 2008 at 05:56:11PM +0100, Oliver Gorwits wrote:
Ideally, DBIC would instead populate the relationship_info details
after someone has set up __PACKAGE__->many_to_many(...). That would
avoid this guesswork.
That would make no sense at all since many-to-many is NOT A
RELATIONSHIP.
I've been in this list for some years now that I've seen this phrase
written several times.
<pedantic>
If I recall correctly my time at CS department where I was forced to
read the relational model (not the -for-dummies version that is SQL
today. but the true horrid version), many-to-many was in fact a
relationship.
In DBIx::Class terms, that's not how we model it.
I know and understand that, but from the outside, can you understand
that given that many_to_many is discussed in
DBIx::Class::Relationships its only natural to people arriving at
DBIx::Class to assume that many_to_many is a relation type like any
other.
I'm not saying that they are right, I'm just saying that its one of
the things that I teach to people who ask me about it: even with
many_to_many defined in ::Relationship, its actually not. Just a bit
of sugar.
Having said that, it is trivial to use your own base class for your
sources in a way that you can catch many-to-many declarations and
cache the result somewhere private (your own version of
relationship_info()).
Please if you do that call it something -other- than
relationship_info.
I say that this is possible because I have code running in production
that does exactly that: creates a parallel relationship_info()
Much DBIC code and extension stuff assumes that anything in there is
a relationship in the DBIC sense.
if you start putting many-to-many stuff in there, your code is
broken. It
just might not have caused you any bugs yet.
I did not start to put many_to_many in relationship_info(), I used a
different name for my relationship introspection code.
relationship_info() is critical for *_related() to work, and I didn't
want to mess that up.
In case my point was not clear enough, I agree that
relationship_info() should only return relations that can be used in
*_related() methods.
But if we have a documented way (cf. ::Relationships) to declare all
this types, I think it makes sense to have a method (a different one
most likely) to return the information about all the relationships you
declared, including many_to_many. This makes it easier to do a lot of
things (like the current recursive insert/update stuff, or a
documentation generation tool).
Best regards,
--
Pedro Melo
Blog: http://www.simplicidade.org/notes/
XMPP ID: [EMAIL PROTECTED]
Use XMPP!
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