ruby on rails - How to modify (encode and decode) routes id, but without changes in the model or controller? -

i want expose database ids , encode/decode id routes helper. encoding use hashids gem.

now have:

routes.rb

get 'companies/:id/:year', to: 'company#show', as: 'companies' 

company url:

/companies/1/2015 

for id encoding have encode/decode helper methods:

def encode(id)    # encode...    return 'abc123' end  def decode(hashid)    # decode...    return 1 end 

how can implemented, id routes helper converted? must show url:

/companies/abc123/2015 

and controller must automatically params id 1.

thanks answers! wont decode params id without changes in model or controller. after long consideration, have decided params id manipulate, before controller params. manipulate params in routes constraints.

example helper:

encoding_helper.rb

module encodinghelper   def encode(id)     # encode...     return 'abc123'   end    def decode(hashid)     # decode...     return 1   end end 

create path encode id:

companies_path(id: encode(1), year: 2015) # => /companies/abc123/2015 

manipulate params in routes constraints:

lib/constraints/decode_company_id.rb

module constraints   class decodeid     extend encodinghelper      def self.matches?(request)       request.params['id'] = decode(request.params['id']).to_s if request.params['id'].present?       true     end   end end 

config/routes.rb

constraints(constraints::decodeid)   'companies/:id/:year', to: 'company#show', as: 'companies' end 

after decode params id constraints und without manipulation in controller, params id 1.