ao tianlong wrote: > i want to write a plugin > that support like following > > Book.search_by_author_and_description(keyword) > i must hold method_missing to dynamic find books > but ActiveRecord already used method_missing . > how can i add onother method_misng method ? > You could alias the existing method_missing, redefine it to capture the cases you are interested in and forward the rest on to the aliased method. Check out Module#alias_method_chain in Rails 1.2: http://weblog.rubyonrails.org/2006/4/26/new-in-rails-module-alias_method_chain Tom