Question

I’m using Rails 3 and Devise 2.0

In the index view of the Posts resource, I want to display a vote button unless the current_user has already voted.

I am only passing in @posts = Post.all into the index view. What’s the best way to check each post to see if the current_user has already voted and render the view accordingly?

I’m currently trying to do this by having a voted? method in my Post model, but the current_user method is not available there.

The other solution I see is to have if letter.votes.find_by_user_id(current_user.id) in the index view, but I’m not sure if this belongs in view logic.

Answer 1

You have a Post, a Vote and a User model

And you want to know when a post has a vote from a specific user

One way to do it could be Justin’s method, but that will produce way too many database queries than needed

A better solution would be to use a has_many :through association like this:

class Post
  has_many :votes
  has_many :voted_users, through: :votes, source: :user
end

And now you can call @posts = Post.includes(:voted_users)

This will eager load all the users that voted on each post

And you could just say

if post.voted_users.include? current_user
  #do stuff
end