Evgeniy Kurtov's Profile

It seems that I should prebuild :fields in controller:
def new
@product_type = ProductType.new
@product_type.fields.build
...
end
or it won't show.

yeah, figured that out! thanks for great work :)

Exactly! I've faced a problem that ember-data simply don't handle nested resources - there is no way to hit /people/:person_id/something, it will be a /people_something for now.
So, it doesn't matter how mature Ember is, it will be just a local toy until ember-data conforms to its level, imho.

Imho Angular and Ember are not in 'versus' position. They both have their use cases.

This is true for all of them actually: Angular is build by guys with strong technical background and if one will to master it than he should understand wide variety of JS templates: factories, providers, injectors and much more.
Ember is evolving so fast that almost all documentation is out of date :)
Joosy is just one of a kind - but I think Rails world only wins from the diversity it brings into it. Again I haven't work with it because of there wasn't such a demand, but I strongly belives that it have it's layer - large scale rich applications.
If one day content generated by Joosy will be compilant with search engines it will really shine as first-class sitizen in a lots of porjects.

Is it possible to use Emblemjs in Slim templates?

Okay, guys you want a Ember vs Angular opinion - here it is:
Angular is more general and 'address root problem that HTML was not designed for dynamic views' in a very sleek way. It's directives is awesome - if u try it once you just cant forget how beautiful they are!
But he is not ready for a big applications, imho. Just look at his nested routing solution - it doesn't have one! There is only 3rd party module in angular-ui https://github.com/angular-ui/ui-router. No surprise it's version is 0.0.1
Ember is rails-aware and and it's your friend in a middle-size applications.
My opinion that Angular is a competitor rather to Backbone than to Ember. I'll use Angular if to drop interactivity here and there and use Ember for a to have a real front-side application, but... here is the sweet part - Joosy(http://www.joosy.ws/)!
So we have solutions for small, midle, and large front-end applicatoins, isn't this wonderful? :)