index_query_filter_before.rb

conditions_strings = []
conditions_params = {}

unless filters[:comment_text].blank?
  conditions_strings << "comments.text ILIKE :comment_text"
  conditions_params[:comment_text] = "%#{filters[:comment_text]}%"
end

conditions = (conditions_params.empty? ? "" : [conditions_strings.join(" AND "), conditions_params])

joins_list = []
joins_list << {:posts => :comment} if filters[:comment_text].present?

posts = Post.where(conditions).joins(joins_list).order("expected_ship_at desc, id desc")