Rails: Preserving GET query string parameters in link_to

Question

I have a typical search facility in my app which returns a list of results that can be paginated, sorted, viewed with a different records_per_page value, etc. Each of these

Answer 1

A bit late i know..

If your using this as a way to filter search results have a look at my helper :)

This automagicly removes all blank and unneeded params and add the class "selected" if all of it's new params were already set.

def search_to s, args={}

  selected = 0
  args.each do |k, v|
    selected = selected + 1 if params[k] == v.to_s || ( params[k].nil? && v.blank? )
  end

  if @search_params_base.nil?
    @search_params_base = request.parameters.clone
    @search_params_base.delete(:action)
    @search_params_base.delete(:controller)
    @search_params_base.delete(:page)
    @search_params_base.delete_if{|k, v| v.nil? || v.blank?}
    @search_params_base.delete(:utf8) if @search_params_base[:keywords].nil?
  end
  search_params = @search_params_base.merge(args)
  search_params.delete_if{|k, v| v.nil? || v.blank?}

  link_to s, search_path + '?' + search_params.to_param, :class => selected == args.length ? 'selected' : nil
end

You can then just use this in your view:

search_to '$80 to $110', :price => 80..110

Or in your case:

search_to '30 per page', :page => params[:page], :per_page => 30