Rails Photos, Users, Comments

Question

Hi,

It's driving me crazy. I have 3 models. User, Photo, Comments.

Here is what I want to do.

A user has many photos and comments

A photo belongs to a user and has many comments

And a comment belongs to user and to a photo

So my models have these associations:

User

has_many :photos, :dependent => :destroy
has_many :comments, :dependent => :destroy

Photo

belongs_to :user
has_many :users, :through => :comments
has_many :comments, :dependent => :destroy

Comment

belongs_to :photo, :user

I want now to show a photo and load all the comments of this photo and display each comment with the user info.

So at the photos controller show action I have

@photo = Photo.find(params[:id], :include => :comments, :order => 'comments.created_at DESC')

And in the photo/show view

=render :partial => "/comments/partials/comment", :collection => @photo.comments, :as => :comment

It display the comments eg. the comment text fine but when inside the partial I try to do:

%p=comment.user.fname
%p=comment.body

It throws error "undefined method `fname' for nil:NilClass"

Something strange is that I am user authlogic so you have to be logged in to post a comment. But you can see the comments even if you are not logged in. When I am logged off it works find. When I log in it throws error.

Any help would be much appreciated cause it is driving me nuts.

By the way in my routes I have

map.resources :users, :has_many => [:photos, :comments]
map.resources :photos, :has_many => [:comments, :users]

Thanks

Answer 1

Not sure this will make a difference, but have you tried separating the belongs_to associations?

belongs_to :photo
belongs_to :user

Answer 2

+1 for using haml

i can think of a few reasons why this might happen

firstly, what happens when your remove the following line from your code?

# try removing this
%p=comment.user.fname

Does the error then move on to next variable (i.e. comment.body)

If not, then you have at least narrowed it down to the fname variable. in which case I would wonder if you have perhaps added the fname variable to your model after creating some intitial database entries... this would mean that some of hte entries don't have associated fname variables. in this instance you can fix the issue by scrubbing the database and remigrating from scratch

Also, do you have attr_accessible set for the fname variable in your model? chekc that you have this set for all the variables.

can you look inside your db and make sure that all entries have an fname variable set?

I realise that you want to get this working but if you can't, there's no shame in using the disqus.com plugin - it saves you db space, helps to attract more comments as lots of people already have profiles and gives you some nifty moderator features... on the downside, you lose branding, and you can't use any of your own rjs effects..

good luck