will_paginate

will_paginate is a pagination library that integrates with Ruby on Rails, Sinatra, Merb, DataMapper and Sequel.

Installation:

## Gemfile for Rails 3+, Sinatra, and Merb
gem 'will_paginate', '~> 3.1.0'

See installation instructions on the wiki for more info.

Basic will_paginate use

## perform a paginated query:
@posts = Post.paginate(:page => params[:page])

# or, use an explicit "per page" limit:
Post.paginate(:page => params[:page], :per_page => 30)

## render page links in the view:
<%= will_paginate @posts %>

And that's it! You're done. You just need to add some CSS styles to make those pagination links prettier.

You can customize the default "per_page" value:

# for the Post model
class Post
  self.per_page = 10
end

# set per_page globally
WillPaginate.per_page = 10

New in Active Record 3:

# paginate in Active Record now returns a Relation
Post.where(:published => true).paginate(:page => params[:page]).order('id DESC')

# the new, shorter page() method
Post.page(params[:page]).order('created_at DESC')

See the wiki for more documentation. Report bugs on GitHub.

Happy paginating.