Ah source code looks crappy here, here's a gist: https://gist.github.com/903276
On Apr 5, 10:56 am, Piotr Solnica <piotr.soln...@gmail.com> wrote: > Hey Nevin, > > We forgive you ;) > > Anyway, here's what you can do: > > class Photo > include DataMapper::Resource > > property :id, Serial > property :caption, String > > has n, :photo_tags > has n, :tags, :through => :photo_tags > end > > class PhotoTag > include DataMapper::Resource > > belongs_to :photo, :key => true > belongs_to :tag, :key => true > end > > class PhotoSet > include DataMapper::Resource > > property :id, Serial > > has n, :photo_set_tags > has n, :tags, :through => :photo_tags > > has n, :photos, :through => :tags > end > > class PhotoSetTag > include DataMapper::Resource > > belongs_to :photo_set, :key => true > belongs_to :tag, :key => true > end > > class Tag > include DataMapper::Resource > > property :id, Serial > property :name, String, :unique => true > > has n, :photo_tags > has n, :photos, :through => :photo_tags > > has n, :photo_set_tags > has n, :photos, :through => :photo_tags > end > > DataMapper.finalize > DataMapper.auto_migrate! > > red_tag = Tag.create(:name => 'red') > green_tag = Tag.create(:name => 'green') > blue_tag = Tag.create(:name => 'blue') > > Photo.create(:caption => "Tagged with red", :tags => > [ red_tag ]) > Photo.create(:caption => "Tagged with green", :tags => > [ green_tag ]) > Photo.create(:caption => "Tagged with green and blue", :tags => > [ green_tag, blue_tag ]) > > photo_set_red = PhotoSet.create(:tags => [ red_tag ]) > photo_set_green_and_blue = PhotoSet.create(:tags => [ green_tag, > blue_tag ]) > > # fetch all the photos from the photo set that has "red" tag > photo_set_red.photos > > # fetch all the photos from the photo set that has "green" and "blue" > tags > photo_set_green_and_blue.photos > > Please also remember that you can use dm-taggings plugins that does > 90% of the above. > > Hope this helps! > > Cheers > > # solnic > > On Apr 5, 9:52 am, Nevin <nevin...@gmail.com> wrote: > > > > > > > > > Hi, > > > Please forgive me that I'm pretty new to datamapper :-P > > > When I reading the associations document in the datamapper web, it > > shows how to do a mapping between Photo <--> Tag via the Tagging > > class. > > > What if I want to further extend the model so that a Set class is > > created to include Photos? The idea is to able to add Tags into a Set > > so I can retrieve all the Photos that have the same Tags. > > > Sets <--- tagging ---> Tags > > Photos <--- tagging ---> Tags > > > So ultimately: > > Set <--- Tags? Tagging? ---> Photos > > > Thanks :-) -- You received this message because you are subscribed to the Google Groups "DataMapper" group. To post to this group, send email to datamapper@googlegroups.com. To unsubscribe from this group, send email to datamapper+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/datamapper?hl=en.
