hoodwink.d enhanced


A Pagination Helper For Rails #

by why in inspect

Sam Stephenson’s PaginationHelper for Rails interacts with ActiveRecord to ensure only a single page of data is loaded from the database and handles links to the other hidden pages. It’s a helper script that I’ve been using everywhere.

Helpers are mixins which add methods to the Rails controller and templates. Install a helper by copying it into /app/helpers/ in your Rails application. Here’s an updated PaginationHelper I’ve updated for Rails 0.90: pagination_helper.rb.

Load the helper at the beginning of a controller like this:

 class BlogPostsController < ApplicationController
   helper :pagination
   include PaginationHelper

Not all helpers require the include statement. We’ll be using the Paginator class inside the helper, so it’s necessary in this case.

Now, you’ll need to use the Paginator in tandem with ActiveRecord#find to grab a single page of data for display:

 @pages = Paginator.new self, BlogPosts.count, 30, @params['page'].to_i
 @posts = BlogPosts.find nil, "post_time DESC", @pages.current.to_sql

My remix of the PaginationHelper (linked above) also features a simple method for generating a window of page links. The Paginator#window_links method accepts your template’s view object and a window size.

I’ve stored my paginator links in a partial called /app/views/partial/_pager.rb:

 <div id="counter">
   Displaying <%= @pages.current.first_item %>
   - <%= @pages.current.last_item %>
   of <%= @pages.item_count %> &nbsp; &nbsp;

   <%= link_to( h('< Previous'), @pages.current.previous.to_link ) + " | " if
     @pages.current.previous %>
   <%= @pages.window_links( self, 4 ) %>
   <%= " | " + link_to( h('Next >'), @pages.current.next.to_link ) if
     @pages.current.next %>
said on 21 Dec 2004 at 04:34
The helper :paginator is a pretty alternative to manually doing the include. You only need one of them, though. So throw away that include statement and live happily ever after ;)
said on 21 Dec 2004 at 08:51
I know it's supposed to work like that, David. But if I don't use include, I get an exception thrown: uninitialized constant ThreadsController::Paginator. Anyway, add_template_helper only mixes the module into the template class, right? I would need to manually mix into the controller class in order to use the helper there.
said on 21 Dec 2004 at 21:11
You don't need the casting in @params['page'].to_i because as written, the paginator helper will cast the page params for you.
said on 14 Apr 2005 at 21:56


said on 29 May 2005 at 01:57

for the test

said on 15 Jun 2005 at 06:47


said on 28 Aug 2005 at 22:25

I want to paginate a search result, that join with other object. The current paginate method suppose to support the whole model colection. Anyoe could point me a solution for this

said on 24 Sep 2005 at 06:07

Liked that

said on 24 Sep 2005 at 06:10

live happily ever after :)

said on 24 Sep 2005 at 06:11

living happily ever after :)

said on 24 Sep 2005 at 06:13


said on 12 Nov 2005 at 18:36


said on 12 Nov 2005 at 18:36


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