snip.rb

scoped = order("#{ sort_by } #{ direction }")

scoped = scoped.where( :publisher_id => params[:publisher_id] ) if params[:publisher_id].present?
scoped = scoped.where( :category_id => params[:category_id] ) if params[:category_id].present?
scoped = scoped.where( "title like ?", "%#{ params[:title] }%" ) if params[:title].present?
scoped = scoped.where( "description like ?", "%#{ params[:description] }%" ) if params[:description].present?

scoped = scoped.drafts if params[:drafts_only].present?
scoped = scoped.published if params[:published_only].present?