Question

Does the render partial function take any type of collection? I tried passing a Set (@dogs) in and it doesn’t seem to work:

<%= render(:partial => "dog", :collection => @dogs, :as => :dog) %>  

I tried looking it up on the docs http://guides.rubyonrails.org/layouts_and_rendering.html but it doesn’t seem to suggest any limitation on sets… Is there something I have missed or another way to find out?

Thanks.

PS But when I tried to convert the very set to an array and it worked.

Answer 1

It won’t work with a set, because the PartialRenderer#collection method attempts to coerce the collection to an array using to_ary:

def collection
  if @options.key?(:collection)
    collection = @options[:collection]
    collection.respond_to?(:to_ary) ? collection.to_ary : []
  end
end

However Sets do not implement to_ary, so, as you have found, you must pass the collection like this:

:collection => @dogs.to_a