Question

I’m having a big problem with will paginate.

I have a query defined as scope in my model:

scope :published_and_valid, joins(...).where(...)

In my controller I sometimes just want to have the top 20.

.limit(20)

Now I want to be able to paginate over these 20 results (5 per page)

And I try to do this:

@articles = Article.published_and_valid.limit(20).paginate(:page => params[:page])

This does not work as the result in my view is a pagineted result for ALL articles

Answer 1

It looks like will_paginate imposes its own limit clause on your relation in order to do the paging. After some experimentation, the easiest way I could find to do this is to do eager-loading of the result set and use the functionality contained in the array extensions to do the actual pagination.

Here’s a quick example; note that you have to require will_paginate/array; you may wish to do this in an initializer or somewhere else. Note that it does monkey-patch Array to have the paginate method.

require 'will_paginate/array'

class ArticlesController < ApplicationController
  def index
    @articles = Article.published.limit(20).all # call `all` to eager load
    @articles = @articles.paginate(:page => params[:page], :per_page => 10)
  end
end

[Update]

Another option is to pass in the total_entires option to will_paginate based on the result set size.

class ArticlesController < ApplicationController
  def index
    @articles = Article.published.limit(20)
    @articles = @articles.paginate(:page => params[:page], :per_page => 10, :total_entries => @articles.count)
  end
end

You can’t pass in 20 as you can’t guarantee that a full 20 results will be returned; by passing in the count attribute, you can ensure that the pagination will be correct.