How to mark a post as viewed?

I have a model, Post, which has a field called is_viewed, which is false when a Post is created.

What is the best way to set is_viewed to true when a post is shown to the user?

Currently, I am having to do this:

class PostsController..

  def show
    #find the post
    @post = current_user.posts.find(params[:id])

    if !@post.is_viewed?
      #mark as viewed
    开发者_运维问答  @post.update_attribute(:is_viewed, true)
      #find the post (again)
      @post = current_user.posts.find(params[:id])
    end
  end
end

In order to load the post only once, I could do this:

if !@post.viewed?
  if @post.update_attribute(:is_viewed, true)
    #simply update the viewed to true, "in memory" so that
    #the view's erb can use the correct value of the "is_viewed" variable
    @post.viewed = true
  end
end

But is that the right thing to do?

Your ruby isn't very rubyish. Typically one doesn't use 'is_' as a prefix as ruby allows method names to end with a question mark. Assuming your field is a boolean you can use @post.viewed? as a shorthand.

Anyway to answer your question, because of ActiveRecord::Dirty there's really no need to check the current state. If you call @post.save on a post for which @post.changed? is false, no update query will be run. So:

@post = current_user.posts.find(params[:id])
@post.viewed = true
@post.save

You don't say why your code reloads the post so I'm going to assume that's bogus. Ruby has an unless keyword so you can replace constructions like if !expr with unless expr.

Also, ruby code looks best indented with 2 spaces :-)