+1 for the usefulness of Jon's patch. During a previous project I was very disappointed to find that Rails didn't support nested :through associations. Besides my own experiences, a quick search on Google for "nested has many through associations" shows a litany of blog posts and discussions on hacks to simulate the functionality.
For example: http://justinfrench.com/notebook/nested-hasmany-through-associations-in-rails http://geoff.evason.name/2010/04/23/nested-has_many-through-in-rails-or-how-to-do-a-3-table-join/ http://kconrails.com/2010/01/28/nesting-has_many-through-relationships-in-ruby-on-rails/ I agree too with José Valim's comments that has_many :through needs to be fixed. The surprising inconsistencies between has_many :through and has_many adds cognitive load to developers and, for me at least, the lack of dependent options has pushed me into using has_many over has_many :through quite a bit. If Jon's code and proposed audit can help iron out these issues then all the better! On Dec 2, 2:01 am, Lunks <pnascime...@gmail.com> wrote: > +1 for sorting bugs out and commiting this. HMT just helps doing some > associations where it would be hard to do. Even if it is not fool proof, > allowing us to associate models further where needed is welcomed. I have > been in a couple of projects where coding would be easier with this patch. > > On Wed, Dec 1, 2010 at 23:44, Jason King <j...@handle.it> wrote: > > I'm very much in favor of hmt working to an infinite depth. From my own > > experience as well as responding to others, I know it's something that > > people just expect to work. > > > I'm also concerned about bugs, but I like your suggestion Jon. > > On Dec 1, 2010 12:18 PM, "Jon Leighton" <j...@jonathanleighton.com> wrote: > > > Hi all, > > > > Jose has responded on the pull request: > > > > =========================================== > > > Hey mate, thanks for the pull request. But could you please send this > > > request to Rails mailing list and get feedback from more people? > > > > At first, I am -1 on this feature. Rails has_many :through, without > > > being nested, already have a few limitations that I really would like to > > > see fixed before adding more complexity. For example, in the case "User > > > has many groups through subscriptions", the following does not work: > > > > group = user.groups.build > > > group.save > > > > As it does not save the associated object subscriptions. > > > Calling .create() works as expected though. The lack of the ability to > > > support a dependent option (like :destroy, :delete) for the associated > > > record is also another limitation (currently we have dangling records). > > > We can find others examples in LH. > > > =========================================== > > > > I wanted to respond here to prevent the discussion being split over > > > multiple places: > > > > I see the concern. Though we should be clear that nested through > > > associations will only ever be read-only, as writing to them would not > > > make any sense (not enough information to determine correct join > > > records). > > > > What I would propose is that I do an audit of tickets on LH that are > > > related to has many through. I suspect some of them will be solved by my > > > patch (as it rewrites lots of HMT code). I could identify others which > > > are still an issue. Then maybe we could identify which other tickets > > > should be fixed before this nested patch goes in. I'm happy to look at > > > other tickets as a stepping stone to getting this patch in. > > > > However it would be good if people could be up front and say now if > > > there are general concerns with this patch in principle, or whether > > > concerns are just around not introducing more bugs in HMT given the > > > number of existing bugs. > > > > Hope that makes sense. > > > > Cheers, > > > Jon > > > > On Mon, 2010-11-29 at 02:27 -0800, Jon Leighton wrote: > > >> The patch has now been "verified" on Lighthouse. I.e. 3 people have > > >> tested and +1ed it. I've done a pull request here: > >https://github.com/rails/rails/pull/121 > > > >> I merged latest master over the weekend and will continue to merge as > > >> necessary to keep it up to date. > > > >> Jon > > > >> On Nov 29, 1:42 am, lardawge <larda...@gmail.com> wrote: > > >> > Jon, > > >> > I would make sure this currently merges into master and send a pull > > >> > request on github with the lighthouse ticket in the comments... Need > > >> > get more eyes on it. > > > >> > On Nov 17, 3:40 am, Jon Leighton <j...@jonathanleighton.com> wrote: > > > >> > > Hi all, > > > >> > > In October I worked on a patch for a long-requested feature: > > >> > > associations that can go :through anything, including other :through > > >> > > associations. > > > >> > > The Lighthouse ticket is here: > >https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/1152 > > > >> > > I believe this is a robust, well-tested patch. I want to get it > > merged, > > >> > > but there has been very little response to the patch on Lighthouse. > > I > > >> > > should probably have posted on here before now - but here I am now > > >> > > anyway. > > > >> > > Can anyone help verify/review this patch? Any suggestions about how > > best > > >> > > to get it accepted by the core team? > > > >> > > Also, can somebody with the relevant permissions changes the status > > from > > >> > > "incomplete" to "open" please? I am actively maintaining the branch > > and > > >> > > merging in the latest master from time to time. I will also happily > > deal > > >> > > with any issues which arise as a result of this patch. > > > >> > > Thanks, > > >> > > Jon Leighton > > > >> > > --http://jonathanleighton.com/ > > > >> > > signature.asc > > >> > > < 1KViewDownload > > > > -- > > >http://jonathanleighton.com/ > > > -- > > You received this message because you are subscribed to the Google Groups > > "Ruby on Rails: Core" group. > > To post to this group, send email to rubyonrails-c...@googlegroups.com. > > To unsubscribe from this group, send email to > > rubyonrails-core+unsubscr...@googlegroups.com<rubyonrails-core%2bunsubscr...@googlegroups.com> > > . > > For more options, visit this group at > >http://groups.google.com/group/rubyonrails-core?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To post to this group, send email to rubyonrails-c...@googlegroups.com. 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