Viewing object associated via "has_many :through"?

rubyonrails-talk
1

You want to use @playlists.playlists_tracks in your view ...

2

I think what you need to do is leverage your has_many :through relationship. Something like:

<% for track in @playlist.track_ones %>   <tr>   <td><%= track.title %></td> </tr> <% end %>

or more idiomatically

<% @playlist.track_ones.each do |track| %>   <tr>   <td><%= track.title %></td> </tr> <% end %>

I don't know your data model, however, the "track_ones" thing kind of smells a bit of an incorrect data model. In general, if you have a table that enumerates a set of columns (track_1, track_2, ...) it may indicate that you are not modeling a parent -> child relationship. It was just a thought ... I am probably barking up the wrong tree ...

3

I believe that Rails uses the :source to identify the foreign key in the join table for the :through relationship. Try this ...

class Playlist < ActiveRecord::Base   ...   has_many :playlists_tracks, :dependent => :destroy   has_many :track_ones, :through => :playlists_tracks, :source => :track_one   has_many :track_twos, :through => :playlists_tracks, :source => :track_two end

Then use the your :through relationships in the view as before ..

4

Yes, you're right!

With this model (like you said):

class Playlist < ActiveRecord::Base   ...   has_many :playlists_tracks, :dependent => :destroy   has_many :track_ones, :through => :playlists_tracks, :source => :track_one   has_many :track_twos, :through => :playlists_tracks, :source => :track_two end

And this in the playlists/show view:

<% for track_one in @playlist.track_ones %>

<tr> <td><%= track_one.title %></td> </tr>

<% end %>

I can display the track's name.

Bill, Thank you so much! I really appreciate your walking me and my noobishness through this. I can now link the last pieces of my application together, and that's a great relief. Cheers!