Why can't I 'count' the results from a model 'find'?

Rails
1

Hi,

I’m running the following code in my show() method:

    @articles = Article.find(:all, :conditions => ["issue_id = ?",

@issue.id], :order => ‘column,position’)

    if (params[:article_id])
      @article_id = params[:article_id].to_i
      c = 0
      total = @articles.count
      while (c < total)
        if @article_id == @articles[c].id
          if c == 0
            @article_prev = @articles.last.id
          else
            @article_prev = @articles[(c-1)].id
          end
          if ((c+1) == total)
            @article_next = @articles.first.id
          else
            @article_next = @articles[(c+1)].id
          end
        end
      end
    else
      @article_id = 0
      @article_main = @articles.first.id
      @article_prev = @articles.last.id
      @article_next = @articles[1].id
    end

Now to be honest this code is already a bit odd for me but I have no
idea how else to approach this in Ruby on Rails. So I’ve attempted to do
it PHP-style. But I’m being told that I can’t do @articles.count

Why? I have a user model and a user has a one to many relationship with
articles so I know that: @user.articles.count works. Hence I’m guessing
there’s something big I’m missing here.

So, how am I going to do this? How do I easily cycle through my list of
articles and get the previous and next ones?

Any help greatly appreciated. I’ve been going back and forth over my
books and forums but I can’t seem to formulate the question to be able
to ask it.

2

On Nov 25, 2008, at 2:40 PM, Theo Graham-brown wrote:

     c = 0
     total = @articles.count

…

guessing
there’s something big I’m missing here.

So, how am I going to do this? How do I easily cycle through my list
of
articles and get the previous and next ones?

@user.articles.count is Rails magic. It’s not actually fetching
everything and then counting it up, it’s looking at the associations
and building a “SELECT COUNT…”

@articles above is an array. Try @articles.size.

-philip

3

On Nov 25, 11:10 pm, Philip H. [email protected] wrote:

On Nov 25, 2008, at 2:40 PM, Theo Graham-brown wrote:

@user.articles.count is Rails magic. It’s not actually fetching
everything and then counting it up, it’s looking at the associations
and building a “SELECT COUNT…”

To be quite precise, @user.articles is not an array, it’s an
association proxy.

Fred

4

Thanks both of you.

I’ve got it working now. :slight_smile: