Symbol-type class_names in associations doesn't work

[VorontsovIE]

I've two models:

class User < ActiveRecord::Base
end

class Deal < ActiveRecord::Base
  belongs_to :owner, :class_name = >:User # or :user
end

Such code in controller:

@deal.owner = current_user

causes an error message: undefined methodmatch' for :user:Symbol but simplу changing:class_name => 'User'` solves the issue. I think it's Rails-style to make both string and symbolic types acceptable.

[sikachu]

This is a long running issue. I can tell that it exists since 2.x.x. I'll have a look into it.

[josevalim]

"I think it's Rails-style to make both string and symbolic types acceptable." No, it is not. This is common on some hashes due to security reasons, but it is not a general style.

[yfeldblum]

@josevalim what is the general style regarding hash keys?

[alexeymuranov]

I haven't noticed this and reported a similar issue (#2530) again.
In my opinion, passing class names as Symbols is more natural, than as Strings.
After all, it is not the content of the "ClassName" that matters here, even if it needs to be parsed.

At least it needs to be documented somewhere.

[yfeldblum]

It is more natural to pass class names as strings, especially when the class name is namespaced.

belongs_to :owner, :class_name => "Admin::User"

[alexeymuranov]

@yfeldblum why?
Splitting on "::" is the only parsing needed, so is this the only reason to pass class names as strings?
Is there a reason to not implement some time in the future splitting on "::" as Symbol#split?
In my opinion, class names are no less "immutable" than attribute names, and attribute name are usually passed as symbols.

[yfeldblum]

It is more natural for the programmer to write

belongs_to :owner, :class_name => "Admin::User"

than for him to write

belongs_to :owner, :class_name => "Admin::User".to_sym

or some variant thereof.

[alexeymuranov]

I would write :'Admin::User'.
I meant being natural from the point of view of the language, not typing.
I agree that to some extent this is also a matter of taste.

[mjnissim]

:class_name=>:user should simply look for User in upper case. When needed, strings can be passed, but it is natural to use symbols.