Updating attributes from retrieved objects that has required attr_acessors - Rails Tutorial - Michael Hartl's

On Chapter 7 from Michael Hartl's tutorial there is a User model <code here> that has a password attribute defined as a attr_accessor and also as attr_accessible with a presence validator.

The problem is: if I retrieve an existent User and try to update its email, ruby throws an exception claiming for its password, and I'm forced to re-set the password every time I want to update any other attribute. Example:

User.first.update_attributes!(:email => "example@mail.com")
ActiveRecord::RecordInvalid: Validation failed: Password can't be blank, Password is too short (minimum is 6 characters)

I开发者_开发百科 added ":on => :create" next to the password's presence validator and it seemed to solve the problem. Is this the right solution regarding a login system?

Anyone who has completed the Michael Harlt's tutorial knows if that was an error or it was his real intention?

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You want to add the validator to the password hash field so that it is the actual password stored in the database which is checked. If you make the password= function set the value of a hash column, then this method will work independently of the actual password virtual variable.