RESTful RESOURCE PARTIAL UPDATE

I have modified scaffolding code slightly to get three edit actions
and three update actions.

The requirement: to allow users to edit attributes for the same model
from seperate forms instead of one form, while using the given
scaffolding code and performing model validations. I am using
restful_authentication with the login email password validations
defined.

class users_controller

  edit_email
  edit_login
  edit_password

  update_email if update_attr save else render => edit_email
  update_login if update_attr save else render => edit_login
  update_password @curr_pass = params[:curr+passs] if update_attr
save else render => edit_password

end

i have made routes

edit_email_path
edit_login_path
edit_password_path
update_email_path
update_login_path
update_password_path

I can get the update_email and update_login to work if I avoid setting
password validations on update. When i set the password validations
on update, i can get the update_password to work, but update_email,
and update_login fail validations because they are trying to validate
passwords too when there is no form elements for them.

Is there a way to make password validations only run when
update_attribute(params[:user]) is called within the update_password
controller method and to prevent password validations to run when
update_email and update_login update_attribute(params[:user]) methods
are called? Thanks in advance.

@curr_pass is defined in update_password for user model user.rb

validate_on_update
  User.authenticate(@user.login, @user.curr_pass)
      errors.add(@curr_pass, 'is incorrect')
end